Cetaceans

The stomachs of 17 cetaceans of seven species (3 Kogia simus, 5 Stenella longirostris, 3 S. graffmani, 2 Lagenorhynchus obliquidens, 2 Delphinus delphis, 1 Lissodelphis borealis, and 1 Phocoena sinus) yielded 18,164 fish otoliths representing over 51 species, 40 genera, and 22 families. Lanternfish (family Myctophidae) otoliths accounted for more than 89% of the total, and they had come from at least 19 species belonging to nine genera. Only two fish species could have been identified if we had not been able to utilize otoliths. To be useful in food studies involving otoliths, cetacean stomachs cannot be placed in formalin solutions, even for short periods.The kinds and diversity of species preyed upon by several of these cetaceans indicate that they routinely forage in depths of 650–800 ft (200–250 m), and a few such as Kogia simus may descend to 1000 ft (300 m) or deeper.

@article{doi101139f68227,
    author = "Fitch, John E. and Brownell, Robert L.",
    title = "Fish Otoliths in Cetacean Stomachs and Their Importance in Interpreting Feeding Habits",
    year = "1968",
    journal = "Journal of the Fisheries Research Board of Canada",
    abstract = "The stomachs of 17 cetaceans of seven species (3 Kogia simus, 5 Stenella longirostris, 3 S. graffmani, 2 Lagenorhynchus obliquidens, 2 Delphinus delphis, 1 Lissodelphis borealis, and 1 Phocoena sinus) yielded 18,164 fish otoliths representing over 51 species, 40 genera, and 22 families. Lanternfish (family Myctophidae) otoliths accounted for more than 89\% of the total, and they had come from at least 19 species belonging to nine genera. Only two fish species could have been identified if we had not been able to utilize otoliths. To be useful in food studies involving otoliths, cetacean stomachs cannot be placed in formalin solutions, even for short periods.The kinds and diversity of species preyed upon by several of these cetaceans indicate that they routinely forage in depths of 650–800 ft (200–250 m), and a few such as Kogia simus may descend to 1000 ft (300 m) or deeper.",
    url = "https://doi.org/10.1139/f68-227",
    doi = "10.1139/f68-227",
    openalex = "W2031500206",
    references = "doi1023071376606"
}

@article{doi1010160305049175900954,
    author = "Litchfield, Carter and Greenberg, Anne J. and Caldwell, David K.‏ and Caldwell, Melba C. and Sipos, J.C. and Ackman, R. G.",
    title = "Comparative lipid patterns in acoustical and nonacoustical fatty tissues of dolphins, porpoises and toothed whales",
    year = "1975",
    journal = "Comparative Biochemistry and Physiology Part B Comparative Biochemistry",
    url = "https://doi.org/10.1016/0305-0491(75)90095-4",
    doi = "10.1016/0305-0491(75)90095-4",
    openalex = "W1990166296"
}

Abstract Modern whaling, using an explosive harpoon fired from a steam catcher‐boat to kill the fast‐swimming rorquals, began from shore whaling stations in northern Norway in the 1860s. It spread to Iceland, the Faeroe Islands and Spitsbergen, before reaching the British Isles in 1903. Whaling took place from four stations in the Shetland Islands, one in the Outer Hebrides, and two in Ireland, before the First World War. Fin whales were the main species caught but Blue, Humpback, Sei, Right, Sperm and Bottle‐nosed whales were also taken. Four stations re‐opened in 1920, but from 1923 onwards only two continued to operate and whaling ceased in 1929, though the Hebridean station worked again for two seasons in 1950–1951. The species composition of catches at the Hebridean and Irish stations was very similar and different from that of the stations in the Shetland Islands where few Blue whales and Right whales were taken. There is evidence that Fin whales were being overfished on the Shetland Islands whaling grounds at an early date, and that Blue whales and Right whales, but not Fin whales, declined in numbers on the Hebridean grounds. The history of modern whaling in the north‐east North Atlantic region as a whole indicates that the stocks of Blue, Humpback and Right whales were not large enough to support continuous whaling on the scale which took place there. The development of whaling since 1945 supports the view that there are separate populations of Fin whales in the region. The numbers of this species have declined on the whaling grounds of the Faeroe Islands and western Norway, and possibly also of north Norway, but not on the Icelandic grounds where there is no evidence of overfishing.

@article{doi101111j136529071976tb00198x,
    author = "Brown, S. G.",
    title = "Modern whaling in Britain and the north‐east Atlantic Ocean",
    year = "1976",
    journal = "Mammal Review",
    abstract = "Abstract Modern whaling, using an explosive harpoon fired from a steam catcher‐boat to kill the fast‐swimming rorquals, began from shore whaling stations in northern Norway in the 1860s. It spread to Iceland, the Faeroe Islands and Spitsbergen, before reaching the British Isles in 1903. Whaling took place from four stations in the Shetland Islands, one in the Outer Hebrides, and two in Ireland, before the First World War. Fin whales were the main species caught but Blue, Humpback, Sei, Right, Sperm and Bottle‐nosed whales were also taken. Four stations re‐opened in 1920, but from 1923 onwards only two continued to operate and whaling ceased in 1929, though the Hebridean station worked again for two seasons in 1950–1951. The species composition of catches at the Hebridean and Irish stations was very similar and different from that of the stations in the Shetland Islands where few Blue whales and Right whales were taken. There is evidence that Fin whales were being overfished on the Shetland Islands whaling grounds at an early date, and that Blue whales and Right whales, but not Fin whales, declined in numbers on the Hebridean grounds. The history of modern whaling in the north‐east North Atlantic region as a whole indicates that the stocks of Blue, Humpback and Right whales were not large enough to support continuous whaling on the scale which took place there. The development of whaling since 1945 supports the view that there are separate populations of Fin whales in the region. The numbers of this species have declined on the whaling grounds of the Faeroe Islands and western Norway, and possibly also of north Norway, but not on the Icelandic grounds where there is no evidence of overfishing.",
    url = "https://doi.org/10.1111/j.1365-2907.1976.tb00198.x",
    doi = "10.1111/j.1365-2907.1976.tb00198.x",
    openalex = "W2159565823"
}

@misc{wursig1979dolphins7,
    author = "Wursig, B",
    title = "Dolphins",
    year = "1979",
    howpublished = "Scientific American, v. 240, no. 3, p. 136-148",
    note = "talkorigins\_source = {true}; raw\_reference = {Wursig, B., 1979, Dolphins: Scientific American, v. 240, no. 3, p. 136-148.}"
}

Abstract Most information on the distribution, movements and ecology of cetaceans in the N.E. Atlantic have come from whale catches mainly in the early part of this century, and from strandings records collected by the British Museum (Nat. Hist.). With the formation of the Cetacean Group in 1973, a scheme for recording live cetaceans at sea was started. This paper summarizes the results of about two thousand sightings involving nearly 25,000 individual animals between the years 1958– 1978 (but mainly from the last 10 years), and relates them to existing information collected from other sources. Difficulties of identification and potential sources of bias are discussed. Most large cetaceans are present in British waters as part of a latitudinal feeding migration whereas smaller species may be present in the N.E. Atlantic throughout the year with movements being mainly of an offshore‐inshore nature. Some species are clearly very rare probably as a result of over‐exploitation in the last century and early part of this century. These include the Right whale, Blue whale and probably Humpback whale. Other species are rarely recorded because their usual range is some distance from British waters. These include narwhal and White whale (from Arctic waters), Pygmy sperm whale, smaller beaked whales and Euphrosyne dolphin (from warm temperate to tropical waters). The Harbour porpoise is by far the most common and widespread species in British waters, occurring mainly in inshore waters, although it has apparently declined in certain regions (e.g. Southern North Sea, English Channel, Irish Sea) in recent years probably as a result of pollution, disturbance and/or over‐exploitation of food resources. Bottle‐nosed and Risso's dolphins are also widely distributed close to the coast, although the latter is restricted to the west and south coasts and the former is associated particularly with some large estuaries. Common dolphins are relatively abundant and widespread, and are more pelagic than the previous three species. White‐sided dolphins have a mainly pelagic distribution centred on the Northern North Sea whilst the White‐sided dolphin has a wider distribution which includes all the western seaboard. Of larger cetaceans, the Killer whale is relatively common particularly on the west coasts and the Pilot whale is locally and seasonally abundant at the north and south ends of Britain and Ireland where they probably represent distinct populations. The Bottlenose whale, Minke, Fin and Sei whales are confined to the west and north coasts, all but the Minke whale having a primarily pelagic distribution. Sperm whales although increasingly commonly stranded on British coasts, are rarely sighted in inshore waters. The west coast of Britain and Ireland are the most important regions for cetaceans whereas the Southern North Sea has the smallest number although in previous decades numbers were probably higher. Most cetacean species occur mainly in the summer months, particularly August and September, although some species, e.g. White‐sided Dolphin, Pilot whale and Minke whale show peaks later in the year. A number of species show secondary spring peaks, e.g. Bottle‐nosed and Common dolphins, Risso's dolphins, and Pilot whales. Present evidence suggests that only the large whales exhibit definite latitudinal migrations, all other species being resident at high latitudes although they may show offshore‐inshore or possibly small latitudinal movements. Many of the movements indicated from the present analysis can be linked to the seasonal changes in food availability and to the timing and geographical location of breeding, and these are described in detail. Many concentrations of a particular cetacean species occur regularly in the same area year after year and these may often be related to spawning concentrations of a particular fish species. Variations in herd size are noted between species and within species at different times of the year. These are related to aggregations associated with feeding, breeding, and long‐distance movements winch will vary according to the biology and ecology of different cetacean species.

@article{doi101111j136529071980tb00232x,
    author = "Evans, Peter G. H.",
    title = "Cetaceans in British waters",
    year = "1980",
    journal = "Mammal Review",
    abstract = "Abstract Most information on the distribution, movements and ecology of cetaceans in the N.E. Atlantic have come from whale catches mainly in the early part of this century, and from strandings records collected by the British Museum (Nat. Hist.). With the formation of the Cetacean Group in 1973, a scheme for recording live cetaceans at sea was started. This paper summarizes the results of about two thousand sightings involving nearly 25,000 individual animals between the years 1958– 1978 (but mainly from the last 10 years), and relates them to existing information collected from other sources. Difficulties of identification and potential sources of bias are discussed. Most large cetaceans are present in British waters as part of a latitudinal feeding migration whereas smaller species may be present in the N.E. Atlantic throughout the year with movements being mainly of an offshore‐inshore nature. Some species are clearly very rare probably as a result of over‐exploitation in the last century and early part of this century. These include the Right whale, Blue whale and probably Humpback whale. Other species are rarely recorded because their usual range is some distance from British waters. These include narwhal and White whale (from Arctic waters), Pygmy sperm whale, smaller beaked whales and Euphrosyne dolphin (from warm temperate to tropical waters). The Harbour porpoise is by far the most common and widespread species in British waters, occurring mainly in inshore waters, although it has apparently declined in certain regions (e.g. Southern North Sea, English Channel, Irish Sea) in recent years probably as a result of pollution, disturbance and/or over‐exploitation of food resources. Bottle‐nosed and Risso's dolphins are also widely distributed close to the coast, although the latter is restricted to the west and south coasts and the former is associated particularly with some large estuaries. Common dolphins are relatively abundant and widespread, and are more pelagic than the previous three species. White‐sided dolphins have a mainly pelagic distribution centred on the Northern North Sea whilst the White‐sided dolphin has a wider distribution which includes all the western seaboard. Of larger cetaceans, the Killer whale is relatively common particularly on the west coasts and the Pilot whale is locally and seasonally abundant at the north and south ends of Britain and Ireland where they probably represent distinct populations. The Bottlenose whale, Minke, Fin and Sei whales are confined to the west and north coasts, all but the Minke whale having a primarily pelagic distribution. Sperm whales although increasingly commonly stranded on British coasts, are rarely sighted in inshore waters. The west coast of Britain and Ireland are the most important regions for cetaceans whereas the Southern North Sea has the smallest number although in previous decades numbers were probably higher. Most cetacean species occur mainly in the summer months, particularly August and September, although some species, e.g. White‐sided Dolphin, Pilot whale and Minke whale show peaks later in the year. A number of species show secondary spring peaks, e.g. Bottle‐nosed and Common dolphins, Risso's dolphins, and Pilot whales. Present evidence suggests that only the large whales exhibit definite latitudinal migrations, all other species being resident at high latitudes although they may show offshore‐inshore or possibly small latitudinal movements. Many of the movements indicated from the present analysis can be linked to the seasonal changes in food availability and to the timing and geographical location of breeding, and these are described in detail. Many concentrations of a particular cetacean species occur regularly in the same area year after year and these may often be related to spawning concentrations of a particular fish species. Variations in herd size are noted between species and within species at different times of the year. These are related to aggregations associated with feeding, breeding, and long‐distance movements winch will vary according to the biology and ecology of different cetacean species.",
    url = "https://doi.org/10.1111/j.1365-2907.1980.tb00232.x",
    doi = "10.1111/j.1365-2907.1980.tb00232.x",
    openalex = "W1969993560"
}

@misc{edwords1982those2,
    author = "Edwords, F",
    title = "Those Amazing Animals",
    year = "1982",
    howpublished = "The Whales and the Dolphins: Creation/ Evolution, v. 3, p. 1-7",
    note = "talkorigins\_source = {true}; raw\_reference = {Edwords, F., 1982, Those Amazing Animals: The Whales and the Dolphins: Creation/ Evolution, v. 3, p. 1-7.}"
}

@misc{landau1982whales5,
    author = "Landau, M",
    title = "Whales",
    year = "1982",
    howpublished = "Can Evolution Account for Them?: Creation/Evolution, v. 10, p. 14-19",
    note = "talkorigins\_source = {true}; raw\_reference = {Landau, M., 1982, Whales: Can Evolution Account for Them?: Creation/Evolution, v. 10, p. 14-19.}"
}

@article{openalexw1572889853,
    author = "Gaskin, D. E.",
    title = "The ecology of whales and dolphins",
    year = "1982",
    openalex = "W1572889853"
}

@misc{conrad1983true1,
    author = "Conrad, E. C",
    title = "True vestigial structures in whales and dolphins",
    year = "1983",
    howpublished = "Creation/ Evolution, v. 3, p. 8-13",
    note = "talkorigins\_source = {true}; raw\_reference = {Conrad, E. C., 1983, True vestigial structures in whales and dolphins: Creation/ Evolution, v. 3, p. 8-13.}"
}

@misc{gingerich1983origin3,
    author = "Gingerich, P. D. and Wells, N. A. and Russell, D. E. and Ibrahim Shah, S. M",
    title = "Origin of whales in epicontinental remnant seas",
    year = "1983",
    howpublished = "new evidence from the early Eocene of Pakistan: Science, v. 220, p. 403-406",
    note = "talkorigins\_source = {true}; raw\_reference = {Gingerich, P. D., Wells, N. A., Russell, D. E., and Ibrahim Shah, S. M., 1983, Origin of whales in epicontinental remnant seas: new evidence from the early Eocene of Pakistan: Science, v. 220, p. 403-406.}"
}

@misc{gish1983creating4,
    author = "Gish, D. T",
    title = "Creating a missing link",
    year = "1983",
    howpublished = "a tale about a whale: ICR Impact Series, v. 123, p. i-iv",
    note = "talkorigins\_source = {true}; raw\_reference = {Gish, D. T., 1983, Creating a missing link: a tale about a whale: ICR Impact Series, v. 123, p. i-iv.}"
}

@misc{landau1983whales6,
    author = "Landau, M",
    title = "Whales",
    year = "1983",
    howpublished = "Can evolution account for them?: Creation/Evolution, v. 3, p. 14-19",
    note = "talkorigins\_source = {true}; raw\_reference = {Landau, M., 1983, Whales: Can evolution account for them?: Creation/Evolution, v. 3, p. 14-19.}"
}

@book{openalexw1537858039,
    author = "Leatherwood, Stephen and Reeves, Randall R. and Foster, Larry",
    title = "The Sierra Club handbook of whales and dolphins",
    year = "1983",
    openalex = "W1537858039"
}

A bstract The authors review the literature on bottlenose dolphin ecology, behavior and social organization, focusing on data collected on free‐ranging animals. Most bottlenose dolphins studied to date have had definable home ranges, and behavioral, morphological and biochemical information indicates discrete stocks in some areas. Bottlenose dolphins appear to form relatively permanent social groups based on sex and age. Mother—calf bonds are long‐lasting. Movement patterns are extremely variable from location to location but are relatively predictable at any given site. Food resources are one of the most important factors affecting movements. Bottlenose dolphin behavior is very flexible, and these dolphins are generally active day and night. Feeding peaks in the morning and afternoon have been observed at several sites. Social behavior is an important component of daily activities. Sharks are the most significant predator on bottlenose dolphins in most areas, but captive and wild studies show that dolphins and sharks frequently live in harmony as well. Human activities may be helpful, harmful or neutral to bottlenose dolphins, but interactions with humans are frequent for these coastal cetaceans.

@article{doi101111j174876921986tb00026x,
    author = "Shane, Susan H. and Wells, Randall S. and Würsig, Bernd",
    title = "ECOLOGY, BEHAVIOR AND SOCIAL ORGANIZATION OF THE BOTTLENOSE DOLPHIN: A REVIEW",
    year = "1986",
    journal = "Marine Mammal Science",
    abstract = "A bstract The authors review the literature on bottlenose dolphin ecology, behavior and social organization, focusing on data collected on free‐ranging animals. Most bottlenose dolphins studied to date have had definable home ranges, and behavioral, morphological and biochemical information indicates discrete stocks in some areas. Bottlenose dolphins appear to form relatively permanent social groups based on sex and age. Mother—calf bonds are long‐lasting. Movement patterns are extremely variable from location to location but are relatively predictable at any given site. Food resources are one of the most important factors affecting movements. Bottlenose dolphin behavior is very flexible, and these dolphins are generally active day and night. Feeding peaks in the morning and afternoon have been observed at several sites. Social behavior is an important component of daily activities. Sharks are the most significant predator on bottlenose dolphins in most areas, but captive and wild studies show that dolphins and sharks frequently live in harmony as well. Human activities may be helpful, harmful or neutral to bottlenose dolphins, but interactions with humans are frequent for these coastal cetaceans.",
    url = "https://doi.org/10.1111/j.1748-7692.1986.tb00026.x",
    doi = "10.1111/j.1748-7692.1986.tb00026.x",
    openalex = "W1984455459"
}

Bird flocks associated with dolphins in the eastern tropical Pacific are described from observations obtained during eight cruises that took place from January to March of 1976, 1977, 1979, and 1980. In the northern tropical waters between latitudes 5°N and 30°N, 43% to 53% of bird flocks co-occurred with dolphins. In equatorial and southern subtropical waters between latitudes 5°N to 12°S and in the central Pacific less than 8% of the flocks were associated with dolphins. In northern tropical waters about 70% of dolphin schools associated with flocks were composed of spotted or spotted plus spinner dolphins; conversely, 59% of spotted dolphin and 96% of spotted plus spinner dolphin schools co-occurred with bird flocks. Most large schools of these dolphins were associated with birds, and the number and diversity of bird species increased with dolphin school size. The average species composition of birds in dolphin-associated flocks of northern tropical waters was: boobies 41.7%, Wedge-tailed Shearwaters (Puffinus pacificus) 31.4%, jaegers 12.8%, Sooty Terns (Sterna fuscata) 6%, frigatebirds 3.6%, and others 4.5%. Positive statistical associations were found among these bird species, which are explained by common attraction to food made available by feeding yellowfin tuna. In the southern latitudes and in the central Pacific, flocks were dominated by Sooty Terns, and few flocks were associated with dolphins. These flocks appeared to be associated with skipjack rather than yellowfin tuna.

@article{doi1023071368877,
    author = "Pitman, Robert L.",
    title = "Seabird Interactions with Dolphins and Tuna in the Eastern Tropical Pacific",
    year = "1986",
    journal = "Ornithological Applications",
    abstract = "Bird flocks associated with dolphins in the eastern tropical Pacific are described from observations obtained during eight cruises that took place from January to March of 1976, 1977, 1979, and 1980. In the northern tropical waters between latitudes 5°N and 30°N, 43\% to 53\% of bird flocks co-occurred with dolphins. In equatorial and southern subtropical waters between latitudes 5°N to 12°S and in the central Pacific less than 8\% of the flocks were associated with dolphins. In northern tropical waters about 70\% of dolphin schools associated with flocks were composed of spotted or spotted plus spinner dolphins; conversely, 59\% of spotted dolphin and 96\% of spotted plus spinner dolphin schools co-occurred with bird flocks. Most large schools of these dolphins were associated with birds, and the number and diversity of bird species increased with dolphin school size. The average species composition of birds in dolphin-associated flocks of northern tropical waters was: boobies 41.7\%, Wedge-tailed Shearwaters (Puffinus pacificus) 31.4\%, jaegers 12.8\%, Sooty Terns (Sterna fuscata) 6\%, frigatebirds 3.6\%, and others 4.5\%. Positive statistical associations were found among these bird species, which are explained by common attraction to food made available by feeding yellowfin tuna. In the southern latitudes and in the central Pacific, flocks were dominated by Sooty Terns, and few flocks were associated with dolphins. These flocks appeared to be associated with skipjack rather than yellowfin tuna.",
    url = "https://doi.org/10.2307/1368877",
    doi = "10.2307/1368877",
    openalex = "W2119052713",
    references = "doi101111j146918091975tb00129x"
}

This study examines the positional relationships of the odontocete (toothed whale) larynx to further an understanding of their breathing, swallowing, and vocalizing abilities. Seventeen specimens representing nine cetacean genera (Delphinus, Stenella, Tursiops, Grampus, Delphinapterus, Globicephala, Kogia, Mesoplodon, and Phocoena) were studied post mortem. Nine specimens were sectioned in the midsagittal plane and the position of the larynx relative to vertebral levels, skull base, and palatal structures was recorded. In eight specimens that could not be bisected for reasons of large size or condition of preservation, the larynx was removed by a ventral approach for further dissection. The results show that the upper respiratory tract of the odontocetes has evolved away from a basic mammalian pattern. Laryngeal position among terrestrial mammals usually corresponds to the level of cervical vertebrae 1-3. The odontocete larynx, however, lies rostral to the level of the atlas and extends to the presphenoidal synchondrosis. Its extension above the level of the foramen magnum is due to three factors: 1) The larynx is elongated into a tubular extension that projects beyond the soft palate into the nasopharynx; 2) the neck region is shortened owing to the highly compressed cervical vertebrae; and 3) the skull base is oriented in the same direction as the cervical vertebrae because of the horizontal and fusiform alignment of the head and thorax. Whereas the larynx of most terrestrial mammals is separable from the nasopharynx, that of the odontocetes studied may be permanently intranarial, held in place by the palatopharyngeal sphincter. Laryngeal position may affect their vocal abilities, allowing odontocetes to simultaneously swallow and echolocate.

@article{doi101002ar1092180115,
    author = "Reidenberg, Joy S. and Laitman, Jeffrey T.",
    title = "Position of the larynx in odontoceti (toothed whales)",
    year = "1987",
    journal = "The Anatomical Record",
    abstract = "This study examines the positional relationships of the odontocete (toothed whale) larynx to further an understanding of their breathing, swallowing, and vocalizing abilities. Seventeen specimens representing nine cetacean genera (Delphinus, Stenella, Tursiops, Grampus, Delphinapterus, Globicephala, Kogia, Mesoplodon, and Phocoena) were studied post mortem. Nine specimens were sectioned in the midsagittal plane and the position of the larynx relative to vertebral levels, skull base, and palatal structures was recorded. In eight specimens that could not be bisected for reasons of large size or condition of preservation, the larynx was removed by a ventral approach for further dissection. The results show that the upper respiratory tract of the odontocetes has evolved away from a basic mammalian pattern. Laryngeal position among terrestrial mammals usually corresponds to the level of cervical vertebrae 1-3. The odontocete larynx, however, lies rostral to the level of the atlas and extends to the presphenoidal synchondrosis. Its extension above the level of the foramen magnum is due to three factors: 1) The larynx is elongated into a tubular extension that projects beyond the soft palate into the nasopharynx; 2) the neck region is shortened owing to the highly compressed cervical vertebrae; and 3) the skull base is oriented in the same direction as the cervical vertebrae because of the horizontal and fusiform alignment of the head and thorax. Whereas the larynx of most terrestrial mammals is separable from the nasopharynx, that of the odontocetes studied may be permanently intranarial, held in place by the palatopharyngeal sphincter. Laryngeal position may affect their vocal abilities, allowing odontocetes to simultaneously swallow and echolocate.",
    url = "https://doi.org/10.1002/ar.1092180115",
    doi = "10.1002/ar.1092180115",
    openalex = "W2054128434"
}

@article{openalexw2344718058,
    author = "De, Silva P H D H",
    title = "CETACEANS WHALES DOLPHINS AND PORPOISES RECORDED OFF SRI LANKA INDIA FROM THE ARABIAN SEA AND GULF GULF OF ADEN AND FROM THE RED SEA",
    year = "1987",
    journal = "Biodiversity Heritage Library (Smithsonian Institution)",
    url = "https://openalex.org/W2344718058",
    openalex = "W2344718058"
}

Species composition, length distribution seasonal variation in occurrence and sex ratio of 174 dolphins from Calicut coast were studied for the period 1976 to 1980. The incidence of dolphins in the gill nets were found to be more during the colder months of the year from October to February. Stenella longirostns contributed 52.9% of the dolphins landed followed by Tursiops adimcus which formed 32.7%. Delphinus delphis tropicalis and Sousa chinensis were the other two species that occurred in the nets

@article{openalexw85967137,
    author = "Mohan, Lal",
    title = "Observations on the by-catch of dolphins Stenella longirostris, Tursiops aduncus, Sousa chinensis and Delphinus delphis Tropicalis in the gill nets off Calicut coast, India",
    year = "1988",
    abstract = "Species composition, length distribution seasonal variation in occurrence and sex ratio of 174 dolphins from Calicut coast were studied for the period 1976 to 1980. The incidence of dolphins in the gill nets were found to be more during the colder months of the year from October to February. Stenella longirostns contributed 52.9\% of the dolphins landed followed by Tursiops adimcus which formed 32.7\%. Delphinus delphis tropicalis and Sousa chinensis were the other two species that occurred in the nets",
    openalex = "W85967137"
}

Abstract: Several species of cetaceans naturally slough visible quantities of skin. We have investigated the prospect of using this material as a viable alternative to the use of biopsy darts for the collection of samples for molecular analysis. Pieces of skin were collected from free‐ranging individuals of three different species—the humpback (Megaptera novaeangliae), sperm (Physeter macrocephalus) and right whales (Eubalaena glacialis). DNA was extracted from 11 pieces of sloughed skin and DNA “fingerprint” profiles prepared. All samples contained DNA of both sufficient quality and quantity for genetic analysis. The applicability of this approach is discussed generally in relation to answering problems about the population structure and breeding systems of cetaceans.

@article{doi101111j174876921992tb00409x,
    author = "Amos, William and Whitehead, H and Ferrari, M. J. and Glockner‐Ferrari, Debbie and Payne, Roger and Gordon, Jonathan",
    title = "RESTRICTABLE DNA FROM SLOUGHED CETACEAN SKIN; ITS POTENTIAL FOR USE IN POPULATION ANALYSIS",
    year = "1992",
    journal = "Marine Mammal Science",
    abstract = "Abstract: Several species of cetaceans naturally slough visible quantities of skin. We have investigated the prospect of using this material as a viable alternative to the use of biopsy darts for the collection of samples for molecular analysis. Pieces of skin were collected from free‐ranging individuals of three different species—the humpback (Megaptera novaeangliae), sperm (Physeter macrocephalus) and right whales (Eubalaena glacialis). DNA was extracted from 11 pieces of sloughed skin and DNA “fingerprint” profiles prepared. All samples contained DNA of both sufficient quality and quantity for genetic analysis. The applicability of this approach is discussed generally in relation to answering problems about the population structure and breeding systems of cetaceans.",
    url = "https://doi.org/10.1111/j.1748-7692.1992.tb00409.x",
    doi = "10.1111/j.1748-7692.1992.tb00409.x",
    openalex = "W2088017963"
}

A total of 2 077 records of approximately 49 000 small cetaceans, including dedicated and incidental sightings and specimens, was analysed to define distribution patterns of the 28 species found within southern African waters. Distribution analyses reveal distinct component patterns, including cosmopolitan (found in all waters) and pelagic cosmopolitan (found in all pelagic waters) components, tropical, subtropical and warm temperate components of the Agulhas Current system, an Agulhas Bank component, a South and East Coast inshore component, and West Coast neritic and pelagic components. While the offshore distribution appears to be determined by water depth, possibly through distribution of the principal prey, longshore distribution appears to be determined by water temperature. The high diversity of small cetacean species found within the relatively small study region results from the wide range of zoogeographic components present. These components arise from the wide range of water temperature resulting from the warm Agulhas Current and the upwelling Benguela system.

@article{doi10298902577619209504706,
    author = "Findlay, Ken and Best, PB and Ross, G. J. B. and Cockcroft, Victor G.",
    title = "The distribution of small odontocete cetaceans off the coasts of South Africa and Namibia",
    year = "1992",
    journal = "South African Journal of Marine Science",
    abstract = "A total of 2 077 records of approximately 49 000 small cetaceans, including dedicated and incidental sightings and specimens, was analysed to define distribution patterns of the 28 species found within southern African waters. Distribution analyses reveal distinct component patterns, including cosmopolitan (found in all waters) and pelagic cosmopolitan (found in all pelagic waters) components, tropical, subtropical and warm temperate components of the Agulhas Current system, an Agulhas Bank component, a South and East Coast inshore component, and West Coast neritic and pelagic components. While the offshore distribution appears to be determined by water depth, possibly through distribution of the principal prey, longshore distribution appears to be determined by water temperature. The high diversity of small cetacean species found within the relatively small study region results from the wide range of zoogeographic components present. These components arise from the wide range of water temperature resulting from the warm Agulhas Current and the upwelling Benguela system.",
    url = "https://doi.org/10.2989/02577619209504706",
    doi = "10.2989/02577619209504706",
    openalex = "W2036539988"
}

The sequence of the mitochondrial control region was determined in all 10 extant species commonly assigned to the suborder Mysticeti (baleen or whalebone whales) and to two odontocete (toothed whale) species (the sperm and the pygmy sperm whale). In the mysticetes, both the length and the sequence of the control region were very similar, with differences occurring primarily in the first approximately 160 bp of the 5' end of the L-strand of the region. There were marked differences between the mysticete and sperm whale sequences and also between the two sperm whales. The control region, less its variable portion, was used in a comparison including the 10 mysticete sequences plus the same region of an Antarctic minke whale specimen and the two sperm whales. The difference between the minke whales from the North Atlantic and the Antarctic was greater than that between any acknowledged species belonging to the same genus (Balaenoptera). The difference was similar to that between the families Balaenopteridae (rorquals) and Eschrichtiidae (gray whales). The findings suggest that the Antarctic minke whale should have a full species status, B. bonaerensis. Parsimony analysis separated the bowhead and the right whale (family Balaenidae) from all remaining mysticetes, including the pygmy right whale. The pygmy right whale is usually included in family Balaenidae. The analysis revealed a close relationship between the gray whale (family Eschrichtiidae) sequence and those of the rorquals (family Balaenopteridae). The gray whale was included in a clade together with the sei, Bryde's, fin, blue, and humpback whales. This clade was separated from the two minke whale types, which branched together.

@article{doi101093oxfordjournalsmolbeva040061,
    author = "Árnason, Úlfur and Gullberg, Anette and Widegren, Bengt",
    title = "Cetacean mitochondrial DNA control region: sequences of all extant baleen whales and two sperm whale species.",
    year = "1993",
    journal = "Molecular Biology and Evolution",
    abstract = "The sequence of the mitochondrial control region was determined in all 10 extant species commonly assigned to the suborder Mysticeti (baleen or whalebone whales) and to two odontocete (toothed whale) species (the sperm and the pygmy sperm whale). In the mysticetes, both the length and the sequence of the control region were very similar, with differences occurring primarily in the first approximately 160 bp of the 5' end of the L-strand of the region. There were marked differences between the mysticete and sperm whale sequences and also between the two sperm whales. The control region, less its variable portion, was used in a comparison including the 10 mysticete sequences plus the same region of an Antarctic minke whale specimen and the two sperm whales. The difference between the minke whales from the North Atlantic and the Antarctic was greater than that between any acknowledged species belonging to the same genus (Balaenoptera). The difference was similar to that between the families Balaenopteridae (rorquals) and Eschrichtiidae (gray whales). The findings suggest that the Antarctic minke whale should have a full species status, B. bonaerensis. Parsimony analysis separated the bowhead and the right whale (family Balaenidae) from all remaining mysticetes, including the pygmy right whale. The pygmy right whale is usually included in family Balaenidae. The analysis revealed a close relationship between the gray whale (family Eschrichtiidae) sequence and those of the rorquals (family Balaenopteridae). The gray whale was included in a clade together with the sei, Bryde's, fin, blue, and humpback whales. This clade was separated from the two minke whale types, which branched together.",
    url = "https://doi.org/10.1093/oxfordjournals.molbev.a040061",
    doi = "10.1093/oxfordjournals.molbev.a040061",
    openalex = "W2136602405"
}

Large-scale research vessel surveys were conducted annually from 1986 through 1990 by the US National Marine Fisheries Service to monitor the abundance of dolphin populations in the eastern tropical Pacific Ocean (ETP). Stratified line-transect surveys with two vessels sampled an area of 19 x 106 km2. Sightings of all cetaceans were recorded, leading to the identification of 29 species. Distribution maps are presented for all species. Data from all five surveys were pooled to give single estimates of abundance in the ETP for 24 stocks of cetaceans representing 19 species or genera. Abundance estimates totaled 9.6 million animals for all dolphin species (subfamilies Delphininae and Steninae), 292,800 for all species in the subfamily Globicephalinae, 45,300 for all species in the family Ziphiidae (beaked whales), 33,881 for all species in the superfamily Physeteroidea, representing 22,666 sperm whales and 11,215 dwarf sperm whales, and 14,431 for two species in the family Balaenopteridae (rorquals), representing 13,023 Bryde’s whales and 1,415 blue whales.

@article{openalexw2125086046,
    author = "Wade, Paul R. and Genodette, Tim",
    title = "Estimates of Cetacean Abundance and Distribution in the Eastern Tropical Pacific",
    year = "1993",
    abstract = "Large-scale research vessel surveys were conducted annually from 1986 through 1990 by the US National Marine Fisheries Service to monitor the abundance of dolphin populations in the eastern tropical Pacific Ocean (ETP). Stratified line-transect surveys with two vessels sampled an area of 19 x 106 km2. Sightings of all cetaceans were recorded, leading to the identification of 29 species. Distribution maps are presented for all species. Data from all five surveys were pooled to give single estimates of abundance in the ETP for 24 stocks of cetaceans representing 19 species or genera. Abundance estimates totaled 9.6 million animals for all dolphin species (subfamilies Delphininae and Steninae), 292,800 for all species in the subfamily Globicephalinae, 45,300 for all species in the family Ziphiidae (beaked whales), 33,881 for all species in the superfamily Physeteroidea, representing 22,666 sperm whales and 11,215 dwarf sperm whales, and 14,431 for two species in the family Balaenopteridae (rorquals), representing 13,023 Bryde’s whales and 1,415 blue whales.",
    openalex = "W2125086046"
}

The present paper deals with the incidental bycatch of dolphins at Fisheries Harbour, Cochin. Catch \nstatistics of dolphins lrom drift gillnets from January 1981 to December 1987 are given. Conservation \nand management of dolphins in India are stressed upon.

@article{openalexw64860075,
    author = "Jayaprakash, A A and Nammalwar, P and Pillai, S Krishna and Elayathu, M N K",
    title = "Incidental by-catch of dolphins at fisheries harbour, Cochin with a note on their conservation and management in India",
    year = "1995",
    journal = "Eprints@CMFRI Open Access Institutional Repository (Central Marine Fisheries Research Institute)",
    abstract = "The present paper deals with the incidental bycatch of dolphins at Fisheries Harbour, Cochin. Catch \nstatistics of dolphins lrom drift gillnets from January 1981 to December 1987 are given. Conservation \nand management of dolphins in India are stressed upon.",
    openalex = "W64860075"
}

Microsatellites are one of the most important classes of nuclear genetic markers and offer many advantages for the study of marine mammals. Here we describe the isolation and characterization of 12 cetacean microsatellites which are then tested across 30 different cetacean species. For around half the species tested, five or more polymorphic loci were identified. Since many species were represented by only one or two specimens, this figure is likely to underestimate the usefulness of these markers. No relationship was found between microsatellite repeat length and proportion of species which gave polymorphic products.

@article{doi101111j1365294x1996tb00301x,
    author = "Valsecchi, Elena and Amos, William",
    title = "Microsatellite markers for the study of cetacean populations",
    year = "1996",
    journal = "Molecular Ecology",
    abstract = "Microsatellites are one of the most important classes of nuclear genetic markers and offer many advantages for the study of marine mammals. Here we describe the isolation and characterization of 12 cetacean microsatellites which are then tested across 30 different cetacean species. For around half the species tested, five or more polymorphic loci were identified. Since many species were represented by only one or two specimens, this figure is likely to underestimate the usefulness of these markers. No relationship was found between microsatellite repeat length and proportion of species which gave polymorphic products.",
    url = "https://doi.org/10.1111/j.1365-294x.1996.tb00301.x",
    doi = "10.1111/j.1365-294x.1996.tb00301.x",
    openalex = "W2118854138",
    references = "doi101038367108a0"
}

Published records of cetaceans stranded on the Irish coast during the period 1901–95 are reviewed. In this review the number of stranding events has been used in the analysis and includes both live strandings and those animals washed up dead. There were 529 records involving 21 species. The Harbour Porpoise (27%) was the most frequently reported species, followed by Common Dolphins (16%) and Pilot Whales (15%). Minke Whales (8%) were the most frequently reported mysticete. The number of reported strandings has increased since the 1960s which is thought to be mainly due to increased observer effort. Cetaceans have stranded on all Irish coasts but mainly along the south coast and along the western seaboard but with no apparent overall seasonal trend. There was a peak in the strandings of Common Dolphins during 1991–92 when 27% (28 records) of all strandings were reported and of White‐sided Dolphins when 60% (28 records) were reported, both of which were attributed to possible interactions with fisheries. The number of Striped Dolphins stranded on the Irish coast has increased steadily since the 1980s and may reflect increasing water temperatures. These stranding records are considered inadequate to determine the status of most species of cetaceans in Irish waters but are sufficient to identify unusual stranding events such as high mortalities due to fisheries interactions or epizootics. More observer coverage is required before the stranding data are adequate for monitoring the status of most species but a stranding scheme is considered the most effective and efficient method of long‐term monitoring of cetaceans in Irish waters.

@article{doi101111j136529071997tb00372x,
    author = "Berrow, Simon and Rogan, Emer",
    title = "Review of cetaceans stranded on the Irish coast, 1901–95",
    year = "1997",
    journal = "Mammal Review",
    abstract = "Published records of cetaceans stranded on the Irish coast during the period 1901–95 are reviewed. In this review the number of stranding events has been used in the analysis and includes both live strandings and those animals washed up dead. There were 529 records involving 21 species. The Harbour Porpoise (27\%) was the most frequently reported species, followed by Common Dolphins (16\%) and Pilot Whales (15\%). Minke Whales (8\%) were the most frequently reported mysticete. The number of reported strandings has increased since the 1960s which is thought to be mainly due to increased observer effort. Cetaceans have stranded on all Irish coasts but mainly along the south coast and along the western seaboard but with no apparent overall seasonal trend. There was a peak in the strandings of Common Dolphins during 1991–92 when 27\% (28 records) of all strandings were reported and of White‐sided Dolphins when 60\% (28 records) were reported, both of which were attributed to possible interactions with fisheries. The number of Striped Dolphins stranded on the Irish coast has increased steadily since the 1980s and may reflect increasing water temperatures. These stranding records are considered inadequate to determine the status of most species of cetaceans in Irish waters but are sufficient to identify unusual stranding events such as high mortalities due to fisheries interactions or epizootics. More observer coverage is required before the stranding data are adequate for monitoring the status of most species but a stranding scheme is considered the most effective and efficient method of long‐term monitoring of cetaceans in Irish waters.",
    url = "https://doi.org/10.1111/j.1365-2907.1997.tb00372.x",
    doi = "10.1111/j.1365-2907.1997.tb00372.x",
    openalex = "W2024166500"
}

Incidental catches of cetaceans in the Dutch pelagic trawl fishery are largely restricted to late-winter early-spring in an area along the continental slope southwest of Ireland. Available evidence indicates that annual variations in such incidents are large. Using combined mid-water trawl by-catch and dolphin stomach content data, the hypothesis is put forward that Atlantic white-sided dolphin (Lagenorhynchus acutus), normally a more oceanic species, may actively search for mackerel (Scomber scombrus) closer to shore in early-spring, at least in some years. Supporting data were from an observer program during 1992–94, which covered seven trips representing 5% of the annual effort in the fishery. Also over the period 1989–94, a total of 71 records of by-catch incidents were collected (involving a minimum of 312 individuals), of which 41 occured in 1994 (172 individuals). Approximately 90% of the incidents occurred late-winter early-spring, when both the mackerel and horse mackerel (Trachurus trachurus) pelagic fisheries were operating in the same area, southwest of Ireland. Incidence frequency peaked by late February and March, when mackerel is known to move into the area during its southward migration. The Atlantic white-sided dolphin was the main cetacean species in the by-catch (83% of all identified individuals). Other species recorded included long-finned pilot whale (Globicephala melas), short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus) and the white-beaked dolphin (Lagenorhynchus albirostris). The stomachs of 47 Atlantic white-sided dolphins, 11 common dolphins, two bottlenose dolphins and one white-beaked dolphin were examined. Fresh mackerel remains were found in nearly all white-sided dolphin stomachs, whereas fresh horse mackerel remains occured only in stomachs of bottlenose and common dolphins. Deep-water fish otolith incidents suggested that white-sided, common and bottlenose dolphin had completely different diets before moving to the southwest of Ireland.

@article{doi102960jv22a16,
    author = "Couperus, A.S.",
    title = "Interactions Between Dutch Midwater Trawl and Atlantic White-sided Dolphins(Lagenorhynchus acutus) Southwest of Ireland",
    year = "1997",
    journal = "Journal of Northwest Atlantic Fishery Science",
    abstract = "Incidental catches of cetaceans in the Dutch pelagic trawl fishery are largely restricted to late-winter early-spring in an area along the continental slope southwest of Ireland. Available evidence indicates that annual variations in such incidents are large. Using combined mid-water trawl by-catch and dolphin stomach content data, the hypothesis is put forward that Atlantic white-sided dolphin (Lagenorhynchus acutus), normally a more oceanic species, may actively search for mackerel (Scomber scombrus) closer to shore in early-spring, at least in some years. Supporting data were from an observer program during 1992–94, which covered seven trips representing 5\% of the annual effort in the fishery. Also over the period 1989–94, a total of 71 records of by-catch incidents were collected (involving a minimum of 312 individuals), of which 41 occured in 1994 (172 individuals). Approximately 90\% of the incidents occurred late-winter early-spring, when both the mackerel and horse mackerel (Trachurus trachurus) pelagic fisheries were operating in the same area, southwest of Ireland. Incidence frequency peaked by late February and March, when mackerel is known to move into the area during its southward migration. The Atlantic white-sided dolphin was the main cetacean species in the by-catch (83\% of all identified individuals). Other species recorded included long-finned pilot whale (Globicephala melas), short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus) and the white-beaked dolphin (Lagenorhynchus albirostris). The stomachs of 47 Atlantic white-sided dolphins, 11 common dolphins, two bottlenose dolphins and one white-beaked dolphin were examined. Fresh mackerel remains were found in nearly all white-sided dolphin stomachs, whereas fresh horse mackerel remains occured only in stomachs of bottlenose and common dolphins. Deep-water fish otolith incidents suggested that white-sided, common and bottlenose dolphin had completely different diets before moving to the southwest of Ireland.",
    url = "https://doi.org/10.2960/j.v22.a16",
    doi = "10.2960/j.v22.a16",
    openalex = "W2092422264"
}

Cetaceans interact with trawls to an undetermined extent. A preliminary review of global data indicates that individuals of 25 cetacean species (two mysticete, 23 odontocete) have been documented to have died in working trawls or discarded trawling gear. Cetacean interactions with trawls are complex, in part because both fishermen and cetaceans are drawn to areas of high prey density. Furthermore, within such areas, cetaceans are probably often attracted to trawling activities because they make it easier for the animals to exploit a concentrated food source. Individuals of 15 (possibly 16) cetacean species (13 odontocete, and one or even two mysticete) have been reported to feed in association with trawls. Animals follow working nets (feeding on stirred-up organisms or fish gilled in mesh) and also feed on discarded by-catch. Damage to gear as a result of feeding interactions or entanglement has been reported. Such damage results in (1) harm to the animals, (2) creation of negative opinions of cetaceans by fishermen (regardless of whether a cetacean or a shark is, in fact, responsible for the damage in question), and (3) loss of time and money for repair and replacement of gear. The relationships of cetaceans with trawls need to be further studied to determine what effects the trawl fisheries have on the ecology and population status of the whales and dolphins involved.

@article{doi102960jv22a17,
    author = "Fertl, Dagmar and Leatherwood, Stephen",
    title = "Cetacean Interactions with Trawls: A Preliminary Review",
    year = "1997",
    journal = "Journal of Northwest Atlantic Fishery Science",
    abstract = "Cetaceans interact with trawls to an undetermined extent. A preliminary review of global data indicates that individuals of 25 cetacean species (two mysticete, 23 odontocete) have been documented to have died in working trawls or discarded trawling gear. Cetacean interactions with trawls are complex, in part because both fishermen and cetaceans are drawn to areas of high prey density. Furthermore, within such areas, cetaceans are probably often attracted to trawling activities because they make it easier for the animals to exploit a concentrated food source. Individuals of 15 (possibly 16) cetacean species (13 odontocete, and one or even two mysticete) have been reported to feed in association with trawls. Animals follow working nets (feeding on stirred-up organisms or fish gilled in mesh) and also feed on discarded by-catch. Damage to gear as a result of feeding interactions or entanglement has been reported. Such damage results in (1) harm to the animals, (2) creation of negative opinions of cetaceans by fishermen (regardless of whether a cetacean or a shark is, in fact, responsible for the damage in question), and (3) loss of time and money for repair and replacement of gear. The relationships of cetaceans with trawls need to be further studied to determine what effects the trawl fisheries have on the ecology and population status of the whales and dolphins involved.",
    url = "https://doi.org/10.2960/j.v22.a17",
    doi = "10.2960/j.v22.a17",
    openalex = "W2130001966"
}

A bstract A simulation method was developed for identifying populations with levels of human‐caused mortality that could lead to depletion, taking into account the uncertainty of available information. A mortality limit (termed the Potential Biological Removal, PBR, under the U. S. Marine Mammal Protection Act) was calculated as the product of a minimum population estimate (N MIN), one‐half of the maximum net productivity rate (R MAX), and a recovery factor (F R). Mortality limits were evaluated based on whether at least 95% of the simulated populations met two criteria: (1) that populations starting at the maximum net productivity level (MNPL) stayed there or above after 20 yr, and (2) that populations starting at 30% of carrying‐capacity (K) recovered to at least MNPL after 100 yr. Simulations of populations that experienced mortality equal to the PBR indicated that using approximately the 20th percentile (the lower 60% log‐normal confidence limit) of the abundance estimate for N MIN met the criteria for both cetaceans (assuming R MAX = 0.04) and pinnipeds (assuming R MAX = 0.12). Additional simulations that included plausible levels of bias in the available information indicated that using a value of 0.5 for F R would meet both criteria during these “bias trials.” It is concluded that any marine mammal population with an estimate of human‐caused mortality that is greater than its PBR has a level of mortality that could lead to the depletion of the population. The simulation methods were also used to show how mortality limits could be calculated to meet conservation goals other than the U. S. goal of maintaining populations above MNPL.

@article{doi101111j174876921998tb00688x,
    author = "Wade, Paul R.",
    title = "CALCULATING LIMITS TO THE ALLOWABLE HUMAN‐CAUSED MORTALITY OF CETACEANS AND PINNIPEDS",
    year = "1998",
    journal = "Marine Mammal Science",
    abstract = "A bstract A simulation method was developed for identifying populations with levels of human‐caused mortality that could lead to depletion, taking into account the uncertainty of available information. A mortality limit (termed the Potential Biological Removal, PBR, under the U. S. Marine Mammal Protection Act) was calculated as the product of a minimum population estimate (N MIN), one‐half of the maximum net productivity rate (R MAX), and a recovery factor (F R). Mortality limits were evaluated based on whether at least 95\% of the simulated populations met two criteria: (1) that populations starting at the maximum net productivity level (MNPL) stayed there or above after 20 yr, and (2) that populations starting at 30\% of carrying‐capacity (K) recovered to at least MNPL after 100 yr. Simulations of populations that experienced mortality equal to the PBR indicated that using approximately the 20th percentile (the lower 60\% log‐normal confidence limit) of the abundance estimate for N MIN met the criteria for both cetaceans (assuming R MAX = 0.04) and pinnipeds (assuming R MAX = 0.12). Additional simulations that included plausible levels of bias in the available information indicated that using a value of 0.5 for F R would meet both criteria during these “bias trials.” It is concluded that any marine mammal population with an estimate of human‐caused mortality that is greater than its PBR has a level of mortality that could lead to the depletion of the population. The simulation methods were also used to show how mortality limits could be calculated to meet conservation goals other than the U. S. goal of maintaining populations above MNPL.",
    url = "https://doi.org/10.1111/j.1748-7692.1998.tb00688.x",
    doi = "10.1111/j.1748-7692.1998.tb00688.x",
    openalex = "W2072494101"
}

A bstract We conducted a cetacean survey in the pelagic western tropical Indian Ocean (WTIO) aboard an 85‐m research vessel from March to July 1995, covering 9,784 linear km. Using 25 × binoculars and line‐transect methods, we recorded 589 sightings of 21 species. Stenella longirostris was the most abundant cetacean, in terms of number of individuals sighted, by an order of magnitude above any other species, while Physeter macrocephalus was the most frequently sighted, in terms of number of schools. Twelve species were widespread, seven were rare, and two were localized; our sightings include new distributional records for 12 species. Significant observations included the following: (1) Delphinus cf. tropicalis was abundant off the coast of Oman (16 sightings) and readily distinguishable in the field from D. delphis and D. capensis, (2) Balaenoptera musculus was fairly common and localized in the area of the Maldives (17 sightings), and (3) three sightings were made of an unidentified bottlenose whale tentatively referred to as Indopacetus (i. e., Mesoplodon) pacificus. We recorded 26 mixed‐species cetacean schools, 43 schools with which seabirds associated, and 17 schools associated with tuna. Notable among these were mixed aggregations of Stenella attenuata, S. longirostris, yellowfin tuna, and seabirds. The cetacean community of the WTIO was similar to that of the eastern tropical Pacific (ETP) and the Gulf of Mexico (GM) in several respects. First, differences in abundance rank of individual species were small, with the result that common species were common and rare species were rare, regardless of ocean. Second, these differences in abundance were due primarily to differences in encounter rate, which varied with ocean by as much as 3,000%, and less so to school size, which generally varied less than 100%. Third, regardless of ocean, three species comprised the majority of cetaceans in the community, Stenella attenuata, S. longirostris, and S. coeruleoalba, representing 62%‐82% of all individuals for all species. However, the rank order of abundance for these three species differed with ocean. Most notably, S. attenuata was abundant in the ETP and GM (abundance rank = 2 and 1, respectively) but much less common in the WTIO (abundance rank = 6). Although habitat preferences for S. attenuata appear to overlap considerably with those of S. longirostris in the ETP, our results suggest there may actually be significant differences between these two species. Detailed analysis of oceanographic correlates of distribution will be necessary in order to understand fully the habitat requirements of these pelagic dolphins, often the most conspicuous elements of tropical cetacean communities around the world.

@article{doi101111j174876921998tb00736x,
    author = "Ballance, Lisa T. and Pitman, Robert L.",
    title = "CETACEANS OF THE WESTERN TROPICAL INDIAN OCEAN: DISTRIBUTION, RELATIVE ABUNDANCE, AND COMPARISONS WITH CETACEAN COMMUNITIES OF TWO OTHER TROPICAL ECOSYSTEMS",
    year = "1998",
    journal = "Marine Mammal Science",
    abstract = "A bstract We conducted a cetacean survey in the pelagic western tropical Indian Ocean (WTIO) aboard an 85‐m research vessel from March to July 1995, covering 9,784 linear km. Using 25 × binoculars and line‐transect methods, we recorded 589 sightings of 21 species. Stenella longirostris was the most abundant cetacean, in terms of number of individuals sighted, by an order of magnitude above any other species, while Physeter macrocephalus was the most frequently sighted, in terms of number of schools. Twelve species were widespread, seven were rare, and two were localized; our sightings include new distributional records for 12 species. Significant observations included the following: (1) Delphinus cf. tropicalis was abundant off the coast of Oman (16 sightings) and readily distinguishable in the field from D. delphis and D. capensis, (2) Balaenoptera musculus was fairly common and localized in the area of the Maldives (17 sightings), and (3) three sightings were made of an unidentified bottlenose whale tentatively referred to as Indopacetus (i. e., Mesoplodon) pacificus. We recorded 26 mixed‐species cetacean schools, 43 schools with which seabirds associated, and 17 schools associated with tuna. Notable among these were mixed aggregations of Stenella attenuata, S. longirostris, yellowfin tuna, and seabirds. The cetacean community of the WTIO was similar to that of the eastern tropical Pacific (ETP) and the Gulf of Mexico (GM) in several respects. First, differences in abundance rank of individual species were small, with the result that common species were common and rare species were rare, regardless of ocean. Second, these differences in abundance were due primarily to differences in encounter rate, which varied with ocean by as much as 3,000\%, and less so to school size, which generally varied less than 100\%. Third, regardless of ocean, three species comprised the majority of cetaceans in the community, Stenella attenuata, S. longirostris, and S. coeruleoalba, representing 62\%‐82\% of all individuals for all species. However, the rank order of abundance for these three species differed with ocean. Most notably, S. attenuata was abundant in the ETP and GM (abundance rank = 2 and 1, respectively) but much less common in the WTIO (abundance rank = 6). Although habitat preferences for S. attenuata appear to overlap considerably with those of S. longirostris in the ETP, our results suggest there may actually be significant differences between these two species. Detailed analysis of oceanographic correlates of distribution will be necessary in order to understand fully the habitat requirements of these pelagic dolphins, often the most conspicuous elements of tropical cetacean communities around the world.",
    url = "https://doi.org/10.1111/j.1748-7692.1998.tb00736.x",
    doi = "10.1111/j.1748-7692.1998.tb00736.x",
    openalex = "W1977167295",
    references = "doi10100797836426546883, doi1010079789401115728, doi101007bf00349552, doi101111j174876921998tb00745x, doi1015259780520913547, doi1023071368877, openalexw1537858039, openalexw2125086046, openalexw2344718058, openalexw2795502180, openalexw3187043151"
}

Abstract Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions; populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right Whales Eubalaena glacialis, Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations, western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and, where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling, existing data indicate strong recovery in most studied populations of these species.

@article{doi101046j13652907199900035x,
    author = "Clapham, Phillip J. and Young, Sharon B. and Brownell, Robert L.",
    title = "Baleen whales: conservation issues and the status of the most endangered populations",
    year = "1999",
    journal = "Mammal Review",
    abstract = "Abstract Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions; populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right Whales Eubalaena glacialis, Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations, western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and, where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling, existing data indicate strong recovery in most studied populations of these species.",
    url = "https://doi.org/10.1046/j.1365-2907.1999.00035.x",
    doi = "10.1046/j.1365-2907.1999.00035.x",
    openalex = "W2013835428",
    references = "doi101038367108a0"
}

Abstract Group dynamics of humpback dolphins Sousa chinensis inhabiting the Algoa Bay region on the south Eastern Cape coast of South Africa, were investigated by means of boat‐based photo‐identification surveys undertaken between May 1991 and May 1994. Groups of humpback dolphins varied in size from three to 24 animals (x̄= seven), with adults representing almost two‐thirds of the group members. Births occurred predominantly in summer. Some females, however, may also cycle outside of the apparent summer breeding season, perhaps indicating a secondary winter season. Circumstantial evidence suggests a minimum of a 3‐year calving interval. Maternal care lasts at least 3–4 years, but female–calf separation is seemingly not related to the female's next pregnancy. Humpback dolphins displayed varying degrees of residence/fidelity to Algoa Bay. Although a few individuals may possibly be classified as ‘resident’, most dolphins were infrequent visitors in the Bay and seem to be transient. The social system of humpback dolphins appears to be fluid with only casual and short‐lasting affiliations. Strong bonds between individuals other than mothers and calves are uncommon. Lack of consistency in the group membership appears to be the general pattern. The weak site fidelity and possibly extensive long‐range movement of the majority of dolphins may contribute to the dynamic nature of humpback dolphin groups. There is probably some form of segregation between sex and/or age classes among humpback dolphins in Eastern Cape waters. The nature and extent of this segregation, however, is not yet sufficiently understood. It is likely that the degree of site fidelity displayed by female humpback dolphins is related to their reproductive stage and increases during the nursing period. Mate‐searching behaviour of male humpback dolphins is the most likely reproductive strategy of the species.

@article{doi101111j146979981999tb00765x,
    author = "Karczmarski, Leszek",
    title = "Group dynamics of humpback dolphins (Sousa chinensis) in the Algoa Bay region, South Africa",
    year = "1999",
    journal = "Journal of Zoology",
    abstract = "Abstract Group dynamics of humpback dolphins Sousa chinensis inhabiting the Algoa Bay region on the south Eastern Cape coast of South Africa, were investigated by means of boat‐based photo‐identification surveys undertaken between May 1991 and May 1994. Groups of humpback dolphins varied in size from three to 24 animals (x̄= seven), with adults representing almost two‐thirds of the group members. Births occurred predominantly in summer. Some females, however, may also cycle outside of the apparent summer breeding season, perhaps indicating a secondary winter season. Circumstantial evidence suggests a minimum of a 3‐year calving interval. Maternal care lasts at least 3–4 years, but female–calf separation is seemingly not related to the female's next pregnancy. Humpback dolphins displayed varying degrees of residence/fidelity to Algoa Bay. Although a few individuals may possibly be classified as ‘resident’, most dolphins were infrequent visitors in the Bay and seem to be transient. The social system of humpback dolphins appears to be fluid with only casual and short‐lasting affiliations. Strong bonds between individuals other than mothers and calves are uncommon. Lack of consistency in the group membership appears to be the general pattern. The weak site fidelity and possibly extensive long‐range movement of the majority of dolphins may contribute to the dynamic nature of humpback dolphin groups. There is probably some form of segregation between sex and/or age classes among humpback dolphins in Eastern Cape waters. The nature and extent of this segregation, however, is not yet sufficiently understood. It is likely that the degree of site fidelity displayed by female humpback dolphins is related to their reproductive stage and increases during the nursing period. Mate‐searching behaviour of male humpback dolphins is the most likely reproductive strategy of the species.",
    url = "https://doi.org/10.1111/j.1469-7998.1999.tb00765.x",
    doi = "10.1111/j.1469-7998.1999.tb00765.x",
    openalex = "W2039646148"
}

A bstract Mark‐recapture analyses were performed on photo‐identification data for Indo‐Pacific humpback dolphins (Sousa chinensis) inhabiting Algoa Bay, on the Eastern Cape coast of South Africa. Boat‐based photo‐ID surveys were undertaken between May 1991 and May 1994. The rate of discovery of newly identified dolphins, distribution of sightings and frequency of resightings of known individuals indicate a high level of seasonal immigration of humpback dolphins into, and emigration from, the Algoa Bay region in summer. Consequently, humpback dolphins from Algoa Bay appear to be part of a substantially larger population that uses a considerable length of the coastal zone. The minimum population size is estimated to be about 466 dolphins.

@article{doi101111j174876921999tb00880x,
    author = "Karczmarski, Leszek and Winter, P.E.D. and Cockcroft, Victor G. and McLachlan, Anton",
    title = "POPULATION ANALYSES OF INDO‐PACIFIC HUMPBACK DOLPHINS SOUSA CHINENSIS IN ALGOA BAY, EASTERN CAPE, SOUTH AFRICA 1",
    year = "1999",
    journal = "Marine Mammal Science",
    abstract = "A bstract Mark‐recapture analyses were performed on photo‐identification data for Indo‐Pacific humpback dolphins (Sousa chinensis) inhabiting Algoa Bay, on the Eastern Cape coast of South Africa. Boat‐based photo‐ID surveys were undertaken between May 1991 and May 1994. The rate of discovery of newly identified dolphins, distribution of sightings and frequency of resightings of known individuals indicate a high level of seasonal immigration of humpback dolphins into, and emigration from, the Algoa Bay region in summer. Consequently, humpback dolphins from Algoa Bay appear to be part of a substantially larger population that uses a considerable length of the coastal zone. The minimum population size is estimated to be about 466 dolphins.",
    url = "https://doi.org/10.1111/j.1748-7692.1999.tb00880.x",
    doi = "10.1111/j.1748-7692.1999.tb00880.x",
    openalex = "W1987405349"
}

A bstract To clarify phylogenetic relationships of Bryde's whales, we examined the nucleotide sequence of the mitochondrial control region and cytochrome b gene in 33 animals: 12 from offshore waters of the western North Pacific, five from off the Solomon Islands, and 16 from the East China Sea and coastal waters of Kochi in southwestern Japan. For reference purposes, homologous sequences from four Balaenoptera species including four Bryde's whales collected in the eastern Indian Ocean were added. We found whales from the three sampling areas to be genetically distinct. The control region sequences suggested that the whales from the three areas separate at higher than the populational level from one another. The cytochrome b data indicated that genetic differences between whales off the Solomon Islands and animals in the other two areas are equivalent to values found among recognized Balaenoptera species, although such a relationship was not observed between the other two areas. We conclude that whales in the East China Sea and coastal waters of Kochi separate from Bryde's whales in offshore waters of the western North Pacific at higher than the populational level but lower than the specific level (i. e., at the subspecific level) and that whales off the Solomon Islands do not belong genetically to the Bryde's whale as previously recognized.

@article{doi101111j174876921999tb00890x,
    author = "Yoshida, Hideyoshi and Kato, Hidehiro",
    title = "PHYLOGENETIC RELATIONSHIPS OF BRYDE'S WHALES IN THE WESTERN NORTH PACIFIC AND ADJACENT WATERS INFERRED FROM MITOCHONDRIAL DNA SEQUENCES 1",
    year = "1999",
    journal = "Marine Mammal Science",
    abstract = "A bstract To clarify phylogenetic relationships of Bryde's whales, we examined the nucleotide sequence of the mitochondrial control region and cytochrome b gene in 33 animals: 12 from offshore waters of the western North Pacific, five from off the Solomon Islands, and 16 from the East China Sea and coastal waters of Kochi in southwestern Japan. For reference purposes, homologous sequences from four Balaenoptera species including four Bryde's whales collected in the eastern Indian Ocean were added. We found whales from the three sampling areas to be genetically distinct. The control region sequences suggested that the whales from the three areas separate at higher than the populational level from one another. The cytochrome b data indicated that genetic differences between whales off the Solomon Islands and animals in the other two areas are equivalent to values found among recognized Balaenoptera species, although such a relationship was not observed between the other two areas. We conclude that whales in the East China Sea and coastal waters of Kochi separate from Bryde's whales in offshore waters of the western North Pacific at higher than the populational level but lower than the specific level (i. e., at the subspecific level) and that whales off the Solomon Islands do not belong genetically to the Bryde's whale as previously recognized.",
    url = "https://doi.org/10.1111/j.1748-7692.1999.tb00890.x",
    doi = "10.1111/j.1748-7692.1999.tb00890.x",
    openalex = "W2146715041",
    references = "doi101006mpev19951043, doi101007bf00173154, doi101007bf01731581, doi101007bf02515385, doi101007pl00006252, doi101093genetics1032287, doi101093nar22224673, doi101093oxfordjournalsmolbeva040061, doi101093oxfordjournalsmolbeva040454, doi101111j174876921992tb00409x"
}

A bstract This paper examines environmental and behavioral determinants of the habitat use and preferences of Indo‐Pacific humpback dolphins inhabiting the Algoa Bay region on the south Eastern Cape coast of South Africa. In order to quantify the habitat use and preference, two indices were used, the Coefficient of Area Use (AU) and the Activity Index (AI). The dolphins inhabit a narrow strip of shallow, inshore waters of Algoa Bay and remain mostly within 400 m of the shore, in water less than 15 m deep, with no apparent preference for clear or turbid water. Water depth is probably the main factor limiting their inshore distribution, and the 25‐m isobath seems to represent the critical depth. Within this confined, inshore distribution, dolphin activities concentrate in the vicinity of rocky reefs‐their primary feeding grounds. Dolphin dependence on these shallow‐water habitats is evident throughout the year and, consequently, the inshore shallow reefs are identified as the “key habitat” which is of primary importance for humpback dolphins in Eastern Cape waters. The dolphins' dependence on this restricted type of habitat within an already restricted inshore distribution makes them particularly vulnerable to alteration or loss of this habitat.

@article{doi101111j174876922000tb00904x,
    author = "Karczmarski, Leszek and Cockcroft, Victor G. and McLachlan, Anton",
    title = "HABITAT USE AND PREFERENCES OF INDO‐PACIFIC HUMPBACK DOLPHINS SOUSA CHINENSIS IN ALGOA BAY, SOUTH AFRICA",
    year = "2000",
    journal = "Marine Mammal Science",
    abstract = "A bstract This paper examines environmental and behavioral determinants of the habitat use and preferences of Indo‐Pacific humpback dolphins inhabiting the Algoa Bay region on the south Eastern Cape coast of South Africa. In order to quantify the habitat use and preference, two indices were used, the Coefficient of Area Use (AU) and the Activity Index (AI). The dolphins inhabit a narrow strip of shallow, inshore waters of Algoa Bay and remain mostly within 400 m of the shore, in water less than 15 m deep, with no apparent preference for clear or turbid water. Water depth is probably the main factor limiting their inshore distribution, and the 25‐m isobath seems to represent the critical depth. Within this confined, inshore distribution, dolphin activities concentrate in the vicinity of rocky reefs‐their primary feeding grounds. Dolphin dependence on these shallow‐water habitats is evident throughout the year and, consequently, the inshore shallow reefs are identified as the “key habitat” which is of primary importance for humpback dolphins in Eastern Cape waters. The dolphins' dependence on this restricted type of habitat within an already restricted inshore distribution makes them particularly vulnerable to alteration or loss of this habitat.",
    url = "https://doi.org/10.1111/j.1748-7692.2000.tb00904.x",
    doi = "10.1111/j.1748-7692.2000.tb00904.x",
    openalex = "W2024616448"
}

This compilation brings together current information on the status of Asian freshwater cetacean populations, the factors that have caused their recent declines, and what can be done to improve their chances for survival. All of the species or populations in quesion are classified as endangered or critically endangered in the 1996 IUCN Red List of Threatened Animals. Includes papers on water development issues, the Yangtze River Dolphin, or Baiji, the Ganges River Dolphin, or Susu, and the Yantgze River population of finless porpoisese. In the final section, five papers address methods for studying freswater cetaceans

@book{openalexw2269059746,
    author = "Reeves, Randall R. and Smith, Brian D. and Kasuya, Toshio",
    title = "Biology and conservation of freshwater cetaceans in Asia",
    year = "2000",
    booktitle = "IUCN eBooks",
    abstract = "This compilation brings together current information on the status of Asian freshwater cetacean populations, the factors that have caused their recent declines, and what can be done to improve their chances for survival. All of the species or populations in quesion are classified as endangered or critically endangered in the 1996 IUCN Red List of Threatened Animals. Includes papers on water development issues, the Yangtze River Dolphin, or Baiji, the Ganges River Dolphin, or Susu, and the Yantgze River population of finless porpoisese. In the final section, five papers address methods for studying freswater cetaceans",
    openalex = "W2269059746",
    references = "openalexw2352602336"
}

SINE (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (Odontoceti), especially river dolphins. Here, we characterize 25 informative SINEs inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these SINE loci to estimate divergence times among lineages. We demonstrate that: (i) Odontocetes are monophyletic; (ii) Ganges River dolphins, beaked whales, and ocean dolphins diverged (in this order) after sperm whales; (iii) three other river dolphin taxa, namely the Amazon, La Plata, and Yangtze river dolphins, form a monophyletic group with Yangtze River dolphins being the most basal; and (iv) the rapid radiation of extant cetacean lineages occurred some 28-33 million years B.P., in strong accord with the fossil record. The combination of SINE and flanking sequence analysis suggests a topology and set of divergence times for odontocete relationships, offering alternative explanations for several long-standing problems in cetacean evolution.

@article{doi101073pnas121139198,
    author = "Nikaido, Masato and Matsuno, Fumio and Hamilton, Healy and Brownell, Robert L. and Cao, Ying and Ding, Wang and Zuoyan, Zhu and Shedlock, Andrew M. and Fordyce, R. Ewan and Hasegawa, Masami and Okada, Norihiro",
    title = "Retroposon analysis of major cetacean lineages: The monophyly of toothed whales and the paraphyly of river dolphins",
    year = "2001",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "SINE (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (Odontoceti), especially river dolphins. Here, we characterize 25 informative SINEs inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these SINE loci to estimate divergence times among lineages. We demonstrate that: (i) Odontocetes are monophyletic; (ii) Ganges River dolphins, beaked whales, and ocean dolphins diverged (in this order) after sperm whales; (iii) three other river dolphin taxa, namely the Amazon, La Plata, and Yangtze river dolphins, form a monophyletic group with Yangtze River dolphins being the most basal; and (iv) the rapid radiation of extant cetacean lineages occurred some 28-33 million years B.P., in strong accord with the fossil record. The combination of SINE and flanking sequence analysis suggests a topology and set of divergence times for odontocete relationships, offering alternative explanations for several long-standing problems in cetacean evolution.",
    url = "https://doi.org/10.1073/pnas.121139198",
    doi = "10.1073/pnas.121139198",
    openalex = "W2149560192"
}

Watching killer whales in the wild in British Columbia and Washington state has become a popular recreational activity in the last decade. Nothing quite matches the thrill of witnessing a pod of these immense creatures cutting through the waters of Johnstone Strait or listening to their strident underwater calls to each other in their own dialect. The new edition of this book presents updated results of over 25 years of killer whale research in British Columbia and Washington. Intended for both whale enthusiasts and researchers, it contains the latest information on what is known of killer whale natural history and presents a catalogue of close to 300 photographs of resident killer whales as well as a genealogical registry that enables readers to identify individual killer whales and their family groups. New in this edition is the latest information on the status and future prospects of west-coast killer whales - how they may be affected by declining salmon stocks, high levels of toxic chemicals in their tissues, and increasing vessel traffic and underwater noise. Whale watchers will particularly appreciate revised suggestions and guidelines on how to view whales in the wild without disturbing them. The authors are active researchers who are widely regarded as the world's foremost authorities on killer whales.

@article{doi105860choice382743,
    title = "Killer whales: the natural history and genealogy of Orinus orca in British Columbia and Washington",
    year = "2001",
    journal = "Choice Reviews Online",
    abstract = "Watching killer whales in the wild in British Columbia and Washington state has become a popular recreational activity in the last decade. Nothing quite matches the thrill of witnessing a pod of these immense creatures cutting through the waters of Johnstone Strait or listening to their strident underwater calls to each other in their own dialect. The new edition of this book presents updated results of over 25 years of killer whale research in British Columbia and Washington. Intended for both whale enthusiasts and researchers, it contains the latest information on what is known of killer whale natural history and presents a catalogue of close to 300 photographs of resident killer whales as well as a genealogical registry that enables readers to identify individual killer whales and their family groups. New in this edition is the latest information on the status and future prospects of west-coast killer whales - how they may be affected by declining salmon stocks, high levels of toxic chemicals in their tissues, and increasing vessel traffic and underwater noise. Whale watchers will particularly appreciate revised suggestions and guidelines on how to view whales in the wild without disturbing them. The authors are active researchers who are widely regarded as the world's foremost authorities on killer whales.",
    url = "https://doi.org/10.5860/choice.38-2743",
    doi = "10.5860/choice.38-2743",
    openalex = "W1591767759"
}

Irish waters are some of the most important in Europe for a wide range of cetacean (whales, dolphins and porpoise) species. Historically whales were hunted in Ireland (Fairley, 1981) but now they are all protected under a wide range of national and EU legislation. However due to a lack of information on the basic ecology and habitat requirements of most species, this important element of Irelands’ fauna is rarely acknowledged in nature conservation and management in Ireland. This paper reviews the biodiversity of marine mammals in Irish waters and briefly discusses issues which may impact on this biodiversity, including actions that will improve our ability to protect the great abundance and diversity of cetaceans around the island of Ireland.

@article{openalexw2546754148,
    author = "Berrow, Simon and Whale, Irish and Quay, Merchants",
    title = "Biological diversity of cetaceans (whales, dolphins and porpoises) in Irish waters.",
    year = "2001",
    abstract = "Irish waters are some of the most important in Europe for a wide range of cetacean (whales, dolphins and porpoise) species. Historically whales were hunted in Ireland (Fairley, 1981) but now they are all protected under a wide range of national and EU legislation. However due to a lack of information on the basic ecology and habitat requirements of most species, this important element of Irelands’ fauna is rarely acknowledged in nature conservation and management in Ireland. This paper reviews the biodiversity of marine mammals in Irish waters and briefly discusses issues which may impact on this biodiversity, including actions that will improve our ability to protect the great abundance and diversity of cetaceans around the island of Ireland.",
    url = "https://openalex.org/W2546754148",
    openalex = "W2546754148",
    references = "doi1010160006320782900891, doi101016s0025326x02002151, doi101016s0165783699000132, doi10103832068, doi101046j13652907200000057x, doi101111j136529071976tb00198x, doi101111j136529071980tb00232x, doi101111j136529071997tb00372x, doi102960jv22a16, openalexw2592014285"
}

A bstract The taxonomic status of common dolphins in the Atlantic and Pacific oceans has been clarified in recent years, with the discovery that there appear to be two species, a short‐beaked (Delphinus delphis) and a long‐beaked (D. capensis) species. However, the taxonomy of common dolphins in the Indian Ocean and southeast Asia is still unclear. A nominal third species, Delphinus tropicalis van Bree, 1971, has been described from this area, but its validity is controversial. We reviewed records and literature on common dolphins from South Africa east to Australia and Japan, and measured 206 skulls of common dolphins from the Indo‐Pacific and southern California. Other than southern Australia, we found no evidence for Delphinus delphis in the Indo‐Pacific (South African specimens appear to be D. capensis). Previous reports of short‐beaked common dolphins in the Indo‐Pacific appear to have been cases of misidentification. The tropicalis ‐form has an exceptionally long and narrow rostrum with high tooth counts, but otherwise appears to resemble D. capensis, in both skeletal and external morphology. From an examination of 86 Delphinus skulls from the reported range of tropicalis (Middle East to China), we found that both tooth counts and rostral length/zygomatic width ratios were higher than for 94 D. capensis specimens from southern Japan, South Africa, and California. These measurements were greatest in the central Indian Ocean (around India). However, there was evidence of clinal variation, with both decreasing as one moves east or west from India, towards South Africa in the west or Japan in the east. We suggest that the tropicalis ‐form is actually a long‐beaked subspecies of D. capensis, which may hybridize or intergrade with the standard capensis ‐form in southeast Asia and possibly along the east coast of Africa. The appropriate name is Delphinus capensis tropicalis (van Bree, 1971), and a formal description of the subspecies is provided.

@article{doi101111j174876922002tb01074x,
    author = "Jefferson, Thomas A. and Waerebeek, Koen Van",
    title = "THE TAXONOMIC STATUS OF THE NOMINAL DOLPHIN SPECIES DELPHINUS TROPICALIS VAN BREE, 1971",
    year = "2002",
    journal = "Marine Mammal Science",
    abstract = "A bstract The taxonomic status of common dolphins in the Atlantic and Pacific oceans has been clarified in recent years, with the discovery that there appear to be two species, a short‐beaked (Delphinus delphis) and a long‐beaked (D. capensis) species. However, the taxonomy of common dolphins in the Indian Ocean and southeast Asia is still unclear. A nominal third species, Delphinus tropicalis van Bree, 1971, has been described from this area, but its validity is controversial. We reviewed records and literature on common dolphins from South Africa east to Australia and Japan, and measured 206 skulls of common dolphins from the Indo‐Pacific and southern California. Other than southern Australia, we found no evidence for Delphinus delphis in the Indo‐Pacific (South African specimens appear to be D. capensis). Previous reports of short‐beaked common dolphins in the Indo‐Pacific appear to have been cases of misidentification. The tropicalis ‐form has an exceptionally long and narrow rostrum with high tooth counts, but otherwise appears to resemble D. capensis, in both skeletal and external morphology. From an examination of 86 Delphinus skulls from the reported range of tropicalis (Middle East to China), we found that both tooth counts and rostral length/zygomatic width ratios were higher than for 94 D. capensis specimens from southern Japan, South Africa, and California. These measurements were greatest in the central Indian Ocean (around India). However, there was evidence of clinal variation, with both decreasing as one moves east or west from India, towards South Africa in the west or Japan in the east. We suggest that the tropicalis ‐form is actually a long‐beaked subspecies of D. capensis, which may hybridize or intergrade with the standard capensis ‐form in southeast Asia and possibly along the east coast of Africa. The appropriate name is Delphinus capensis tropicalis (van Bree, 1971), and a formal description of the subspecies is provided.",
    url = "https://doi.org/10.1111/j.1748-7692.2002.tb01074.x",
    doi = "10.1111/j.1748-7692.2002.tb01074.x",
    openalex = "W2157574413",
    references = "doi1015159789882200159016"
}

ABSTRACT 1. Monitoring spatial and temporal patterns in cetacean abundance involves a variety of approaches depending upon the target species and the resources available. As a first step, the collection of incidental sightings or strandings information aids the construction of a species list and a rough measure of status and seasonal variation in abundance. These often make use of networks of volunteer observers although the wide variation in abilities and experience means that special attention must be paid to training and to data quality control. More robust monitoring of numbers requires quantification of effort and some correction for factors that influence detectability, such as sea state. 2. The presence of cetaceans may be recorded visually, or indirectly by acoustics. Each has advantages and disadvantages, and their applicability may vary between species. The use of fixed stations tends to allow sustained monitoring at relatively low cost but coverage is limited to the immediate vicinity. For more extensive coverage, mobile platforms are necessary. Platforms of opportunity such as ferries, whale‐watching boats, etc. are often used to survey areas at low cost. These may allow repeat observations to be made over time, but with no control over where the vessel goes, it is typically not possible to sample wide areas, thus limiting abundance estimation. 3. Line transect surveys using dedicated platforms allow representative coverage of areas from which abundance estimates can be made (either using indices or absolute measures derived from density estimation). Assumptions relating to detectability and responsiveness need to be addressed and various methods (such as two‐platform surveys) have been developed to accommodate these. 4. For some cetacean species, mark‐recapture methods can be applied using photo‐identification of recognizable individuals. Again, a number of assumptions are made, particularly relating to recognizability, representativeness of sampling and capture probabilities. Capturing, on film, as many animals in the population as possible helps to reduce the problem of heterogeneity of capture probabilities. Mark‐recapture methods require at least two sampling occasions. If multiple sampling is employed, either open or closed population models can be used. 5. Measuring population change represents a particular challenge for mobile animals such as cetaceans. Changes in ranging patterns may have a large impact on abundance estimates unless very large areas are adequately covered. Power analysis is a useful method to indicate the ability of the data to detect a trend of a given magnitude. Increasingly, spatial modelling using GLMs and GAMs is being used to provide a better understanding of the biotic and hydrographic factors influencing cetacean distribution.

@article{doi101046j03051838200300027x,
    author = "Evans, Peter G. H. and Hammond, Philip S.",
    title = "Monitoring cetaceans in European waters",
    year = "2003",
    journal = "Mammal Review",
    abstract = "ABSTRACT 1. Monitoring spatial and temporal patterns in cetacean abundance involves a variety of approaches depending upon the target species and the resources available. As a first step, the collection of incidental sightings or strandings information aids the construction of a species list and a rough measure of status and seasonal variation in abundance. These often make use of networks of volunteer observers although the wide variation in abilities and experience means that special attention must be paid to training and to data quality control. More robust monitoring of numbers requires quantification of effort and some correction for factors that influence detectability, such as sea state. 2. The presence of cetaceans may be recorded visually, or indirectly by acoustics. Each has advantages and disadvantages, and their applicability may vary between species. The use of fixed stations tends to allow sustained monitoring at relatively low cost but coverage is limited to the immediate vicinity. For more extensive coverage, mobile platforms are necessary. Platforms of opportunity such as ferries, whale‐watching boats, etc. are often used to survey areas at low cost. These may allow repeat observations to be made over time, but with no control over where the vessel goes, it is typically not possible to sample wide areas, thus limiting abundance estimation. 3. Line transect surveys using dedicated platforms allow representative coverage of areas from which abundance estimates can be made (either using indices or absolute measures derived from density estimation). Assumptions relating to detectability and responsiveness need to be addressed and various methods (such as two‐platform surveys) have been developed to accommodate these. 4. For some cetacean species, mark‐recapture methods can be applied using photo‐identification of recognizable individuals. Again, a number of assumptions are made, particularly relating to recognizability, representativeness of sampling and capture probabilities. Capturing, on film, as many animals in the population as possible helps to reduce the problem of heterogeneity of capture probabilities. Mark‐recapture methods require at least two sampling occasions. If multiple sampling is employed, either open or closed population models can be used. 5. Measuring population change represents a particular challenge for mobile animals such as cetaceans. Changes in ranging patterns may have a large impact on abundance estimates unless very large areas are adequately covered. Power analysis is a useful method to indicate the ability of the data to detect a trend of a given magnitude. Increasingly, spatial modelling using GLMs and GAMs is being used to provide a better understanding of the biotic and hydrographic factors influencing cetacean distribution.",
    url = "https://doi.org/10.1046/j.0305-1838.2003.00027.x",
    doi = "10.1046/j.0305-1838.2003.00027.x",
    openalex = "W2124430626"
}

Populations of seals, sea lions, and sea otters have sequentially collapsed over large areas of the northern North Pacific Ocean and southern Bering Sea during the last several decades. A bottom-up nutritional limitation mechanism induced by physical oceanographic change or competition with fisheries was long thought to be largely responsible for these declines. The current weight of evidence is more consistent with top-down forcing. Increased predation by killer whales probably drove the sea otter collapse and may have been responsible for the earlier pinniped declines as well. We propose that decimation of the great whales by post-World War II industrial whaling caused the great whales' foremost natural predators, killer whales, to begin feeding more intensively on the smaller marine mammals, thus "fishing-down" this element of the marine food web. The timing of these events, information on the abundance, diet, and foraging behavior of both predators and prey, and feasibility analyses based on demographic and energetic modeling are all consistent with this hypothesis.

@article{doi101073pnas1635156100,
    author = "Springer, Alan M. and Estes, James A. and van Vliet, Gus B. and Williams, Terrie M. and Doak, Daniel F. and Danner, Eric M. and Forney, Karin A. and Pfister, B.",
    title = "Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?",
    year = "2003",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = {Populations of seals, sea lions, and sea otters have sequentially collapsed over large areas of the northern North Pacific Ocean and southern Bering Sea during the last several decades. A bottom-up nutritional limitation mechanism induced by physical oceanographic change or competition with fisheries was long thought to be largely responsible for these declines. The current weight of evidence is more consistent with top-down forcing. Increased predation by killer whales probably drove the sea otter collapse and may have been responsible for the earlier pinniped declines as well. We propose that decimation of the great whales by post-World War II industrial whaling caused the great whales' foremost natural predators, killer whales, to begin feeding more intensively on the smaller marine mammals, thus "fishing-down" this element of the marine food web. The timing of these events, information on the abundance, diet, and foraging behavior of both predators and prey, and feasibility analyses based on demographic and energetic modeling are all consistent with this hypothesis.},
    url = "https://doi.org/10.1073/pnas.1635156100",
    doi = "10.1073/pnas.1635156100",
    openalex = "W2081645934"
}

Abstract: Nature‐based tourism activities have been developing over the last decade, but it is still difficult to manage these activities sustainably. This sector is increasingly focusing on whales and dolphins in coastal communities, but the exact effects of these tourism activities are unclear. Markov chain modeling may help researchers assess the effects of tourism activities on the behavioral budget of small cetaceans. Matrix models have been used widely in population ecology to provide successful management guidelines. From June 2000 to August 2001, I collected information on the behavioral state of bottlenose dolphin (Tursiops spp.) schools from a population residing in Doubtful Sound, Fiordland, New Zealand. In addition, I recorded the occurrence of boat and dolphin interactions. I then calculated the transition probabilities of passing from one behavior to another by using a first‐order, time‐discrete Markov chain model. Behavioral transitions during which a boat‐dolphin interaction occurred were compiled in an “impact” chain. All other transitions were tallied in a control chain. I then quantified the effect of boat‐dolphin interactions during behavioral transitions by comparing the behavioral transition probabilities of both chains. Socializing and resting behaviors were disrupted by interactions with boats to a level that raises concern. Both the duration of bouts and the total amount of time spent in both these behavioral states were substantially decreased. Dolphins were significantly more likely to be traveling after an interaction with a boat. However, the overall behavioral budget of the population was not significantly affected. Therefore, the bottlenose dolphin population seems to be able to sustain the present level of boat interactions because of its low intensity. More effort is needed to develop prognosis analyses in order to understand how the effect of boat interactions on dolphins changes with variations in intensity.

@article{doi101111j15231739200300054x,
    author = "Lusseau, David",
    title = "Effects of Tour Boats on the Behavior of Bottlenose Dolphins: Using Markov Chains to Model Anthropogenic Impacts",
    year = "2003",
    journal = "Conservation Biology",
    abstract = "Abstract: Nature‐based tourism activities have been developing over the last decade, but it is still difficult to manage these activities sustainably. This sector is increasingly focusing on whales and dolphins in coastal communities, but the exact effects of these tourism activities are unclear. Markov chain modeling may help researchers assess the effects of tourism activities on the behavioral budget of small cetaceans. Matrix models have been used widely in population ecology to provide successful management guidelines. From June 2000 to August 2001, I collected information on the behavioral state of bottlenose dolphin (Tursiops spp.) schools from a population residing in Doubtful Sound, Fiordland, New Zealand. In addition, I recorded the occurrence of boat and dolphin interactions. I then calculated the transition probabilities of passing from one behavior to another by using a first‐order, time‐discrete Markov chain model. Behavioral transitions during which a boat‐dolphin interaction occurred were compiled in an “impact” chain. All other transitions were tallied in a control chain. I then quantified the effect of boat‐dolphin interactions during behavioral transitions by comparing the behavioral transition probabilities of both chains. Socializing and resting behaviors were disrupted by interactions with boats to a level that raises concern. Both the duration of bouts and the total amount of time spent in both these behavioral states were substantially decreased. Dolphins were significantly more likely to be traveling after an interaction with a boat. However, the overall behavioral budget of the population was not significantly affected. Therefore, the bottlenose dolphin population seems to be able to sustain the present level of boat interactions because of its low intensity. More effort is needed to develop prognosis analyses in order to understand how the effect of boat interactions on dolphins changes with variations in intensity.",
    url = "https://doi.org/10.1111/j.1523-1739.2003.00054.x",
    doi = "10.1111/j.1523-1739.2003.00054.x",
    openalex = "W1973943139"
}

Consistent evaluation and new recommendations for action are required of protective measures to address threats that were unrecognised or non-existent until recently. Global warming, noise pollution and reduced availability of prey are now of great concern. The all too familiar threats of accidental killing in fishing gear and exposure to toxic chemicals remain almost intractable. This Action Plan reviews threats and offers possible solutions. It also contains a thorough review of the status of species and a list of 57 recommended research projects and education initiatives

@book{doi102305iucnch2003sscap2en,
    author = "Smith, Brian D. and Crespo, Enrique A. and di Sciara, Giuseppe Notarbartolo",
    title = "Dolphins, whales and porpoises: 2002-2010 conservation action plan for the world's cetaceans",
    year = "2003",
    booktitle = "IUCN eBooks",
    abstract = "Consistent evaluation and new recommendations for action are required of protective measures to address threats that were unrecognised or non-existent until recently. Global warming, noise pollution and reduced availability of prey are now of great concern. The all too familiar threats of accidental killing in fishing gear and exposure to toxic chemicals remain almost intractable. This Action Plan reviews threats and offers possible solutions. It also contains a thorough review of the status of species and a list of 57 recommended research projects and education initiatives",
    url = "https://doi.org/10.2305/iucn.ch.2003.ssc-ap.2.en",
    doi = "10.2305/iucn.ch.2003.ssc-ap.2.en",
    openalex = "W2217880123",
    references = "doi1010160967065396842815, doi101038367108a0, doi101111j174876921999tb00890x, doi1015159789882200159016, openalexw2352602336"
}

@article{doi101016jbiocon200403017,
    author = "Whitehead, Hal and Rendell, Luke and Osborne, Richard W. and Würsig, Bernd",
    title = "Culture and conservation of non-humans with reference to whales and dolphins: review and new directions",
    year = "2004",
    journal = "Biological Conservation",
    url = "https://doi.org/10.1016/j.biocon.2004.03.017",
    doi = "10.1016/j.biocon.2004.03.017",
    openalex = "W2115710419",
    references = "doi1010160967065396842815"
}

Records of Indo-Pacific humpback dolphin sightings, strandings, and museum specimens in the Arabian region were compiled and used to review the distribution and status of this species. Nominal usage of Sousa chinensis (Osbeck, 1765) has been retained as a pragmatic measure, although the species present in the region resembles Sousa plumbea (Cuvier, 1828). Little is known about the ecology of this species in the region. Most available information on S. chinensis in the region originates from the Sultanate of Oman, where this species is among the most commonly recorded cetaceans; however, there is no absolute measure of abundance for anywhere in the region and the status of the species is unknown. Distribution is described for the region to include much of the Arabian (Persian) Gulf, Arabian Sea, Gulf of Aden, and Red Sea, but notably excludes the Gulf of Oman. This discontinuous distribution suggests the possible presence of discrete populations within the region. Beach-cast/dead individuals represent nearly two-thirds of all records (n=303) of this species in Oman. Live sightings indicate unusually large group sizes (up to 100 individuals) in the Arabian Sea and Arabian Gulf. Occasional associations with Tursiops sp. and Delphinus capensis tropicalis were documented. Mating behavior and the presence of calves were recorded in the months of April and May, and calves were also reported in June, October, November, and December. Threats to humpback dolphins in the Arabian region include incidental capture in fishing nets, coastal and offshore development (e.g., land reclamation, dredging, port and harbor construction), pollution, boat traffic, oil and gas exploration (including seismic surveying), military exercises, and biotoxins associated with red tide events. Evidence for historic and current directed catches of S. chinensis is limited, but opportunistic hunting may occur. Intraspecific variation in cranial measurements of individuals from the Arabian Sea coast of Oman fall within relative values found in individuals from the Saudi Arabian Gulf coast. Cranial abnormalities were few. Recommendations are made for conservation management-oriented research focusing on stock identity and status assessments, as well as for monitoring of fisheries by-catch, clearer definition of other threats, continued specimen and sample collection, and training of local scientists.

@article{doi101578am3012004111,
    author = "Baldwin, R.M. and Collins, Moth and Waerebeek, Koen Van and Minton, Gianna",
    title = "The Indo-Pacific Humpback Dolphin of the Arabian Region: A Status Review",
    year = "2004",
    journal = "Aquatic Mammals",
    abstract = "Records of Indo-Pacific humpback dolphin sightings, strandings, and museum specimens in the Arabian region were compiled and used to review the distribution and status of this species. Nominal usage of Sousa chinensis (Osbeck, 1765) has been retained as a pragmatic measure, although the species present in the region resembles Sousa plumbea (Cuvier, 1828). Little is known about the ecology of this species in the region. Most available information on S. chinensis in the region originates from the Sultanate of Oman, where this species is among the most commonly recorded cetaceans; however, there is no absolute measure of abundance for anywhere in the region and the status of the species is unknown. Distribution is described for the region to include much of the Arabian (Persian) Gulf, Arabian Sea, Gulf of Aden, and Red Sea, but notably excludes the Gulf of Oman. This discontinuous distribution suggests the possible presence of discrete populations within the region. Beach-cast/dead individuals represent nearly two-thirds of all records (n=303) of this species in Oman. Live sightings indicate unusually large group sizes (up to 100 individuals) in the Arabian Sea and Arabian Gulf. Occasional associations with Tursiops sp. and Delphinus capensis tropicalis were documented. Mating behavior and the presence of calves were recorded in the months of April and May, and calves were also reported in June, October, November, and December. Threats to humpback dolphins in the Arabian region include incidental capture in fishing nets, coastal and offshore development (e.g., land reclamation, dredging, port and harbor construction), pollution, boat traffic, oil and gas exploration (including seismic surveying), military exercises, and biotoxins associated with red tide events. Evidence for historic and current directed catches of S. chinensis is limited, but opportunistic hunting may occur. Intraspecific variation in cranial measurements of individuals from the Arabian Sea coast of Oman fall within relative values found in individuals from the Saudi Arabian Gulf coast. Cranial abnormalities were few. Recommendations are made for conservation management-oriented research focusing on stock identity and status assessments, as well as for monitoring of fisheries by-catch, clearer definition of other threats, continued specimen and sample collection, and training of local scientists.",
    url = "https://doi.org/10.1578/am.30.1.2004.111",
    doi = "10.1578/am.30.1.2004.111",
    openalex = "W2080048746",
    references = "doi1010160198025487902834, doi101111j146979981999tb00765x, doi101578am30120043, doi105479si03629236246, doi105962bhltitle130093, doi105962bhltitle57674, openalexw108323744, openalexw1537858039, openalexw1594849078, openalexw2344718058"
}

The Indo-Pacific humpback dolphin (Sousa chinensis, Osbeck, 1765) is found in coastal waters throughout the Indian and western Pacific Oceans, but the species has not been studied in detail along the coast of India. Records of stranded specimens, occasional sightings, incidental catches, and museum specimens are reviewed here, and these show that humpback dolphins occur along most Indian coastal areas and in northwest Sri Lanka. There also are two sighting records for the northeast Andaman Islands. An overview is given of a project carried out recently to study coastal cetacean populations in two areas along the west coast of India. Boat surveys were carried out along the coast of Goa and in the Gulf of Kachchh Marine Protected Area. The distribution, group size, and an index of abundance for S. chinensis in the two regions are evaluated. The sighting rate was over six times higher in Goa.

@article{doi101578am3012004125,
    author = "Sutaria, Dipani and Jefferson, Thomas A.",
    title = "Records of Indo-Pacific Humpback Dolphins (Sousa chinensis, Osbeck, 1765) Along the Coasts of India and Sri Lanka: An Overview",
    year = "2004",
    journal = "Aquatic Mammals",
    abstract = "The Indo-Pacific humpback dolphin (Sousa chinensis, Osbeck, 1765) is found in coastal waters throughout the Indian and western Pacific Oceans, but the species has not been studied in detail along the coast of India. Records of stranded specimens, occasional sightings, incidental catches, and museum specimens are reviewed here, and these show that humpback dolphins occur along most Indian coastal areas and in northwest Sri Lanka. There also are two sighting records for the northeast Andaman Islands. An overview is given of a project carried out recently to study coastal cetacean populations in two areas along the west coast of India. Boat surveys were carried out along the coast of Goa and in the Gulf of Kachchh Marine Protected Area. The distribution, group size, and an index of abundance for S. chinensis in the two regions are evaluated. The sighting rate was over six times higher in Goa.",
    url = "https://doi.org/10.1578/am.30.1.2004.125",
    doi = "10.1578/am.30.1.2004.125",
    openalex = "W2166666348",
    references = "doi1010160025326x93905733, doi101016s0141113697000160, doi101016s0964569196000701, doi101038086277b0, doi101111j174876921998tb00702x, doi101578am30120043, doi105479si03629236361, openalexw2344718058, openalexw64860075, openalexw652054596"
}

Dietary information derived from the examination of stomach contents of 29 Indo-Pacific humpback dolphins (Sousa chinensis) stranded in Hong Kong waters is presented in this study. Humpback dolphins in this area have a diet comprised nearly exclusively of fish. Prey spectrum from the 15 dolphins with contents includes a minimum of 24 species of fish, and one species of cephalopod. The croaker (Johnius sp.) was the most frequent and numerically most important prey, followed by the lionhead (Collichthys lucida) and anchovies (Thryssa spp.). The fish families Sciaenidae, Engraulidae, Trichiuridae, and Clupeidae accounted for over 93% of all prey consumed. Most of these prey are common in murky, brackish waters of estuaries and often occur in large shoals. There is some dietary overlap with finless porpoises (Neophocaena phocaenoides); the two species share some 13 fish species, but only anchovies figure among the top five prey for both species. In addition, finless porpoises rely more heavily on cephalopods (squids, cuttlefishes, and octopus) and may venture into deeper, clearer waters during foraging, whereas humpback dolphins seem to exploit demersal and shoaling fish of productive estuaries. The stocks of some fish species important in the diet of humpback dolphins may have been subjected to heavy exploitation by the fisheries in Hong Kong waters. Behavioral observations of dolphins feeding in association with pair trawlers suggest a somewhat different prey preference for some dolphins from the results of this study.

@article{doi101578am3012004179,
    author = "Barros, Nélio B. and Jefferson, Thomas A. and Parsons, E. C. M.",
    title = "Feeding Habits of Indo-Pacific Humpback Dolphins (Sousa chinensis) Stranded in Hong Kong",
    year = "2004",
    journal = "Aquatic Mammals",
    abstract = "Dietary information derived from the examination of stomach contents of 29 Indo-Pacific humpback dolphins (Sousa chinensis) stranded in Hong Kong waters is presented in this study. Humpback dolphins in this area have a diet comprised nearly exclusively of fish. Prey spectrum from the 15 dolphins with contents includes a minimum of 24 species of fish, and one species of cephalopod. The croaker (Johnius sp.) was the most frequent and numerically most important prey, followed by the lionhead (Collichthys lucida) and anchovies (Thryssa spp.). The fish families Sciaenidae, Engraulidae, Trichiuridae, and Clupeidae accounted for over 93\% of all prey consumed. Most of these prey are common in murky, brackish waters of estuaries and often occur in large shoals. There is some dietary overlap with finless porpoises (Neophocaena phocaenoides); the two species share some 13 fish species, but only anchovies figure among the top five prey for both species. In addition, finless porpoises rely more heavily on cephalopods (squids, cuttlefishes, and octopus) and may venture into deeper, clearer waters during foraging, whereas humpback dolphins seem to exploit demersal and shoaling fish of productive estuaries. The stocks of some fish species important in the diet of humpback dolphins may have been subjected to heavy exploitation by the fisheries in Hong Kong waters. Behavioral observations of dolphins feeding in association with pair trawlers suggest a somewhat different prey preference for some dolphins from the results of this study.",
    url = "https://doi.org/10.1578/am.30.1.2004.179",
    doi = "10.1578/am.30.1.2004.179",
    openalex = "W1966526542",
    references = "doi101578am3012004111"
}

The taxonomy and systematic relationships of humpback dolphins (genus Sousa) are highly confused. This is largely due to a lack of data and samples from large portions of the range of the genus, and confusing and seemingly contradictory patterns of variation in available external morphometric, skeletal morphometric, and molecular datasets. To help clarify the situation, we measured 222 skulls of humpback dolphins originating from throughout most regions of the range of Sousa. While patterns of cranial variation appeared to be relatively conservative, there was evidence for three groups: (1) Atlantic Ocean/West Africa, (2) Western Indian Ocean, and (3) Eastern Indian Ocean/Pacific Ocean. These would appear to correspond to the teuszii, plumbea, and chinensis forms, respectively. No taxonomic revisions are recommended at this time, and the conservative view of two species (S. teuszii in West Africa and S. chinensis in the Indo-Pacific) can be defended for the time being as a pragmatic approach. The distinctness of S. teuszii is clearcut, but other taxonomic decisions should await further studies of molecular genetics and morphometrics, currently underway.

@article{doi101578am30120043,
    author = "Jefferson, Thomas A. and Waerebeek, Koen Van",
    title = "Geographic Variation in Skull Morphology of Humpback Dolphins (Sousa spp.)",
    year = "2004",
    journal = "Aquatic Mammals",
    abstract = "The taxonomy and systematic relationships of humpback dolphins (genus Sousa) are highly confused. This is largely due to a lack of data and samples from large portions of the range of the genus, and confusing and seemingly contradictory patterns of variation in available external morphometric, skeletal morphometric, and molecular datasets. To help clarify the situation, we measured 222 skulls of humpback dolphins originating from throughout most regions of the range of Sousa. While patterns of cranial variation appeared to be relatively conservative, there was evidence for three groups: (1) Atlantic Ocean/West Africa, (2) Western Indian Ocean, and (3) Eastern Indian Ocean/Pacific Ocean. These would appear to correspond to the teuszii, plumbea, and chinensis forms, respectively. No taxonomic revisions are recommended at this time, and the conservative view of two species (S. teuszii in West Africa and S. chinensis in the Indo-Pacific) can be defended for the time being as a pragmatic approach. The distinctness of S. teuszii is clearcut, but other taxonomic decisions should await further studies of molecular genetics and morphometrics, currently underway.",
    url = "https://doi.org/10.1578/am.30.1.2004.3",
    doi = "10.1578/am.30.1.2004.3",
    openalex = "W2168422692",
    references = "doi101578am3012004111, doi101578am3012004125"
}

@article{crossref2005whales,
    title = "Whales, Dolphins, and Porpoises: Presentation of the Cetaceans",
    year = "2005",
    journal = "Aquatic Mammals",
    url = "https://doi.org/10.1578/am.31.3.2005.288",
    doi = "10.1578/am.31.3.2005.288",
    number = "3",
    openalex = "W4243547650",
    pages = "288-310",
    volume = "31"
}

Blue whales Balaenoptera musculus meet the highest prey demands of any predator that has ever existed by feeding exclusively upon dense but patchy schools of pelagic euphausiids. We examined the role that seasonally high primary production supported by coastal upwelling combined with topographic breaks off California play in creating, collecting, and maintaining euphausiids at densities sufficient to allow exploitation by whales. We used concurrent ship-and mooringbased oceanographic, hydroacoustic, and net sampling, whale-sighting records, visual surveys, and time-depth recorder deployment to examine temporal and spatial linkages between (1) intensity of upwelling, (2) primary production, (3) development, density and distribution of euphausiids, and (4) the distribution, abundance, and foraging behavior of blue whales in Monterey Bay, California between 1992 and 1996. Blue whales fed exclusively upon adult euphausiids Thysanoessa spinifera and Euphausia pacifica that were larger than those generally available in the Bay. Foraging whales dove repeatedly to dense euphausiid aggregations between 150 and 200 m on the edge of the Monterey Bay Submarine Canyon. Euphausiid aggregations where whales were foraging averaged 153 g m -3, approximately 2 orders of magnitude greater than mean euphausiid densities in the Bay (1.3 g m -3). High euphausiid densities are supported by high primary production between April and August (249 mg C m -3 d -1) and a submarine canyon that provides deep water down-current from an upwelling region. Peak euphausiid densities occur in late summer/early fall, lagging the seasonal increase in primary production by 3 to 4 mo. This lag results from the temporal development of euphausiids spawned around the spring increase in primary production and the shoreward collapse of productivity due to decreased upwelling in late summer. The migratory movements of the California blue whale probably reflect seasonal patterns in productivity in other foraging areas similar to those we describe for Monterey Bay.

@article{doi103354meps289117,
    author = "Croll, DA and Marinović, Branka and Benson, S. and Chavez, FP and Black, Nancy A. and Ternullo, Richard and Tershy, BR",
    title = "From wind to whales: trophic links in a coastal upwelling system",
    year = "2005",
    journal = "Marine Ecology Progress Series",
    abstract = "Blue whales Balaenoptera musculus meet the highest prey demands of any predator that has ever existed by feeding exclusively upon dense but patchy schools of pelagic euphausiids. We examined the role that seasonally high primary production supported by coastal upwelling combined with topographic breaks off California play in creating, collecting, and maintaining euphausiids at densities sufficient to allow exploitation by whales. We used concurrent ship-and mooringbased oceanographic, hydroacoustic, and net sampling, whale-sighting records, visual surveys, and time-depth recorder deployment to examine temporal and spatial linkages between (1) intensity of upwelling, (2) primary production, (3) development, density and distribution of euphausiids, and (4) the distribution, abundance, and foraging behavior of blue whales in Monterey Bay, California between 1992 and 1996. Blue whales fed exclusively upon adult euphausiids Thysanoessa spinifera and Euphausia pacifica that were larger than those generally available in the Bay. Foraging whales dove repeatedly to dense euphausiid aggregations between 150 and 200 m on the edge of the Monterey Bay Submarine Canyon. Euphausiid aggregations where whales were foraging averaged 153 g m -3, approximately 2 orders of magnitude greater than mean euphausiid densities in the Bay (1.3 g m -3). High euphausiid densities are supported by high primary production between April and August (249 mg C m -3 d -1) and a submarine canyon that provides deep water down-current from an upwelling region. Peak euphausiid densities occur in late summer/early fall, lagging the seasonal increase in primary production by 3 to 4 mo. This lag results from the temporal development of euphausiids spawned around the spring increase in primary production and the shoreward collapse of productivity due to decreased upwelling in late summer. The migratory movements of the California blue whale probably reflect seasonal patterns in productivity in other foraging areas similar to those we describe for Monterey Bay.",
    url = "https://doi.org/10.3354/meps289117",
    doi = "10.3354/meps289117",
    openalex = "W2007301479"
}

Kreb, Daniëlle, Budiono (2005): Cetacean Diversity And Habitat Preferences In Tropical Waters Of East Kalimantan, Indonesia. Raffles Bulletin of Zoology 53 (1): 149-155, DOI: 10.5281/zenodo.13245040

@article{doi105281zenodo13245039,
    author = "Kreb, Daniëlle and Budiono",
    title = "Cetacean Diversity And Habitat Preferences In Tropical Waters Of East Kalimantan, Indonesia",
    year = "2005",
    abstract = "Kreb, Daniëlle, Budiono (2005): Cetacean Diversity And Habitat Preferences In Tropical Waters Of East Kalimantan, Indonesia. Raffles Bulletin of Zoology 53 (1): 149-155, DOI: 10.5281/zenodo.13245040",
    url = "https://doi.org/10.5281/zenodo.13245039",
    doi = "10.5281/zenodo.13245039",
    openalex = "W2167383047"
}

1. Many species of delphinids co-occur in space and time. However, little is known of their ecological interactions and the underlying mechanisms that mediate their coexistence. 2. Snubfin Orcaella heinsohni, and Indo-Pacific humpback dolphins Sousa chinensis, live in sympatry throughout most of their range in Australian waters. I conducted boat-based surveys in Cleveland Bay, north-east Queensland, to collect data on the space and habitat use of both species. Using Geographic Information Systems, kernel methods and Euclidean distances I investigated interspecific differences in their space use patterns, behaviour and habitat preferences. 3. Core areas of use (50% kernel range) for both species were located close to river mouths and modified habitat such as dredged channels and breakwaters close to the Port of Townsville. Foraging and travelling activities were the dominant behavioural activities of snubfin and humpback dolphins within and outside their core areas. 4. Their representative ranges (95% kernel range) overlapped considerably, with shared areas showing strong concordance in the space use by both species. Nevertheless, snubfin dolphins preferred slightly shallower (1-2 m) waters than humpback dolphins (2-5 m). Additionally, shallow areas with seagrass ranked high in the habitat preferences of snubfin dolphins, whereas humpback dolphins favoured dredged channels. 5. Slight differences in habitat preferences appear to be one of the principal factors maintaining the coexistence of snubfin and humpback dolphins. I suggest diet partitioning and interspecific aggression as the major forces determining habitat selection in these sympatric species.

@article{doi101111j13652656200601104x,
    author = "Parra, Guido J.",
    title = "Resource partitioning in sympatric delphinids: space use and habitat preferences of Australian snubfin and Indo‐Pacific humpback dolphins",
    year = "2006",
    journal = "Journal of Animal Ecology",
    abstract = "1. Many species of delphinids co-occur in space and time. However, little is known of their ecological interactions and the underlying mechanisms that mediate their coexistence. 2. Snubfin Orcaella heinsohni, and Indo-Pacific humpback dolphins Sousa chinensis, live in sympatry throughout most of their range in Australian waters. I conducted boat-based surveys in Cleveland Bay, north-east Queensland, to collect data on the space and habitat use of both species. Using Geographic Information Systems, kernel methods and Euclidean distances I investigated interspecific differences in their space use patterns, behaviour and habitat preferences. 3. Core areas of use (50\% kernel range) for both species were located close to river mouths and modified habitat such as dredged channels and breakwaters close to the Port of Townsville. Foraging and travelling activities were the dominant behavioural activities of snubfin and humpback dolphins within and outside their core areas. 4. Their representative ranges (95\% kernel range) overlapped considerably, with shared areas showing strong concordance in the space use by both species. Nevertheless, snubfin dolphins preferred slightly shallower (1-2 m) waters than humpback dolphins (2-5 m). Additionally, shallow areas with seagrass ranked high in the habitat preferences of snubfin dolphins, whereas humpback dolphins favoured dredged channels. 5. Slight differences in habitat preferences appear to be one of the principal factors maintaining the coexistence of snubfin and humpback dolphins. I suggest diet partitioning and interspecific aggression as the major forces determining habitat selection in these sympatric species.",
    url = "https://doi.org/10.1111/j.1365-2656.2006.01104.x",
    doi = "10.1111/j.1365-2656.2006.01104.x",
    openalex = "W2138085322",
    references = "doi1016441545141020016550001sc20co2"
}

Studies evaluating effects of human activity on wildlife typically emphasize short-term behavioral responses from which it is difficult to infer biological significance or formulate plans to mitigate harmful impacts. Based on decades of detailed behavioral records, we evaluated long-term impacts of vessel activity on bottlenose dolphins (Tursiops sp.) in Shark Bay, Australia. We compared dolphin abundance within adjacent 36-km2 tourism and control sites, over three consecutive 4.5-year periods wherein research activity was relatively constant but tourism levels increased from zero, to one, to two dolphin-watching operators. A nonlinear logistic model demonstrated that there was no difference in dolphin abundance between periods with no tourism and periods in which one operator offered tours. As the number of tour operators increased to two, there was a significant average decline in dolphin abundance (14.9%; 95% CI=-20.8 to -8.23), approximating a decline of one per seven individuals. Concurrently, within the control site, the average increase in dolphin abundance was not significant (8.5%; 95% CI=-4.0 to +16.7). Given the substantially greater presence and proximity of tour vessels to dolphins relative to research vessels, tour-vessel activity contributed more to declining dolphin numbers within the tourism site than research vessels. Although this trend may not jeopardize the large, genetically diverse dolphin population of Shark Bay, the decline is unlikely to be sustainable for local dolphin tourism. A similar decline would be devastating for small, closed, resident, or endangered cetacean populations. The substantial effect of tour vessels on dolphin abundance in a region of low-level tourism calls into question the presumption that dolphin-watching tourism is benign.

@article{doi101111j15231739200600540x,
    author = "Bejder, Lars and Samuels, Amy and Whitehead, Hal and Gales, Nick and Mann, Janet and Connor, Richard C. and HEITHAUS, MIKE and Watson-Capps, Jana J. and Flaherty, Cindy and Krützen, Michael",
    title = "Decline in Relative Abundance of Bottlenose Dolphins Exposed to Long‐Term Disturbance",
    year = "2006",
    journal = "Conservation Biology",
    abstract = "Studies evaluating effects of human activity on wildlife typically emphasize short-term behavioral responses from which it is difficult to infer biological significance or formulate plans to mitigate harmful impacts. Based on decades of detailed behavioral records, we evaluated long-term impacts of vessel activity on bottlenose dolphins (Tursiops sp.) in Shark Bay, Australia. We compared dolphin abundance within adjacent 36-km2 tourism and control sites, over three consecutive 4.5-year periods wherein research activity was relatively constant but tourism levels increased from zero, to one, to two dolphin-watching operators. A nonlinear logistic model demonstrated that there was no difference in dolphin abundance between periods with no tourism and periods in which one operator offered tours. As the number of tour operators increased to two, there was a significant average decline in dolphin abundance (14.9\%; 95\% CI=-20.8 to -8.23), approximating a decline of one per seven individuals. Concurrently, within the control site, the average increase in dolphin abundance was not significant (8.5\%; 95\% CI=-4.0 to +16.7). Given the substantially greater presence and proximity of tour vessels to dolphins relative to research vessels, tour-vessel activity contributed more to declining dolphin numbers within the tourism site than research vessels. Although this trend may not jeopardize the large, genetically diverse dolphin population of Shark Bay, the decline is unlikely to be sustainable for local dolphin tourism. A similar decline would be devastating for small, closed, resident, or endangered cetacean populations. The substantial effect of tour vessels on dolphin abundance in a region of low-level tourism calls into question the presumption that dolphin-watching tourism is benign.",
    url = "https://doi.org/10.1111/j.1523-1739.2006.00540.x",
    doi = "10.1111/j.1523-1739.2006.00540.x",
    openalex = "W2132750032",
    references = "doi10100797814757990957, doi101016c20090022533, doi101016s0006320700000021, doi101093beheco112210, doi101098rsbl20040225, doi101111j00218901200400900x, doi101111j174876921999tb00784x, doi101139z90092, doi101163156853992x00101, doi105751es00404060111"
}

Abstract Historical records demonstrate that the most numerous, per capita, ocean‐going‐vessel strikes recorded among large‐whale species accrue to the North Atlantic right whale (Eubalaena glacialis). As vessel speed restrictions are being considered to reduce the likelihood and severity of vessel collisions with right whales, we present an analysis of the published historical records of vessels striking large whales. We examine the influence of vessel speed in contributing to either a lethal injury (defined as killed or severely injured) or a nonlethal injury (defined as minor or no apparent injury) to a large whale when struck. A logistic regression model fitted to the observations, and consistent with a bootstrap model, demonstrates that the greatest rate of change in the probability of a lethal injury (P lethal) to a large whale occurs between vessel speeds of 8.6 and 15 knots where P lethal increases from 0.21 to 0.79. The probability of a lethal injury drops below 0.5 at 11.8 knots. Above 15 knots, P lethal asymptotically approaches 1. The uncertainties in the logistic regression estimates are relatively large at relatively low speeds (e.g., at 8 knots the probability is 0.17 with a 95% CI of 0.03–0.6). The results we provide can be used to assess the utility of vessel speed limits that are being considered to reduce the lethality of vessels striking the critically endangered North Atlantic right whale and other large whales that are frequent victims of vessel strikes.

@article{doi101111j17487692200600098x,
    author = "Vanderlaan, Angelia S. M. and Taggart, Christopher T.",
    title = "VESSEL COLLISIONS WITH WHALES: THE PROBABILITY OF LETHAL INJURY BASED ON VESSEL SPEED",
    year = "2006",
    journal = "Marine Mammal Science",
    abstract = "Abstract Historical records demonstrate that the most numerous, per capita, ocean‐going‐vessel strikes recorded among large‐whale species accrue to the North Atlantic right whale (Eubalaena glacialis). As vessel speed restrictions are being considered to reduce the likelihood and severity of vessel collisions with right whales, we present an analysis of the published historical records of vessels striking large whales. We examine the influence of vessel speed in contributing to either a lethal injury (defined as killed or severely injured) or a nonlethal injury (defined as minor or no apparent injury) to a large whale when struck. A logistic regression model fitted to the observations, and consistent with a bootstrap model, demonstrates that the greatest rate of change in the probability of a lethal injury (P lethal) to a large whale occurs between vessel speeds of 8.6 and 15 knots where P lethal increases from 0.21 to 0.79. The probability of a lethal injury drops below 0.5 at 11.8 knots. Above 15 knots, P lethal asymptotically approaches 1. The uncertainties in the logistic regression estimates are relatively large at relatively low speeds (e.g., at 8 knots the probability is 0.17 with a 95\% CI of 0.03–0.6). The results we provide can be used to assess the utility of vessel speed limits that are being considered to reduce the lethality of vessels striking the critically endangered North Atlantic right whale and other large whales that are frequent victims of vessel strikes.",
    url = "https://doi.org/10.1111/j.1748-7692.2006.00098.x",
    doi = "10.1111/j.1748-7692.2006.00098.x",
    openalex = "W2144270142"
}

Dave Wall, Joanne O'Brien, John Meade, Brendan M. Allen, SUMMER DISTRIBUTION AND RELATIVE ABUNDANCE OF CETACEANS OFF THE WEST COAST OF IRELAND, Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 106B, No. 2 (AUGUST 2006), pp. 135-142

@article{doi103318bioe20061062135,
    author = "Wall, Dave and O’Brien, Joanne and Meade, John and Allen, Brendan M.",
    title = "Summer Distribution and Relative Abundance of Cetaceans off the West Coast of Ireland",
    year = "2006",
    journal = "Biology \& Environment Proceedings of the Royal Irish Academy",
    abstract = "Dave Wall, Joanne O'Brien, John Meade, Brendan M. Allen, SUMMER DISTRIBUTION AND RELATIVE ABUNDANCE OF CETACEANS OFF THE WEST COAST OF IRELAND, Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 106B, No. 2 (AUGUST 2006), pp. 135-142",
    url = "https://doi.org/10.3318/bioe.2006.106.2.135",
    doi = "10.3318/bioe.2006.106.2.135",
    openalex = "W2156842898",
    references = "openalexw2546754148"
}

The Yangtze River dolphin or baiji (Lipotes vexillifer), an obligate freshwater odontocete known only from the middle-lower Yangtze River system and neighbouring Qiantang River in eastern China, has long been recognized as one of the world's rarest and most threatened mammal species. The status of the baiji has not been investigated since the late 1990s, when the surviving population was estimated to be as low as 13 individuals. An intensive six-week multi-vessel visual and acoustic survey carried out in November-December 2006, covering the entire historical range of the baiji in the main Yangtze channel, failed to find any evidence that the species survives. We are forced to conclude that the baiji is now likely to be extinct, probably due to unsustainable by-catch in local fisheries. This represents the first global extinction of a large vertebrate for over 50 years, only the fourth disappearance of an entire mammal family since AD 1500, and the first cetacean species to be driven to extinction by human activity. Immediate and extreme measures may be necessary to prevent the extinction of other endangered cetaceans, including the sympatric Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis).

@article{doi101098rsbl20070292,
    author = "Turvey, Samuel T. and Pitman, Robert L. and Taylor, Barbara L. and Barlow, Jay and Akamatsu, Tomonari and Barrett, Leigh A. and Zhao, Xiujiang and Reeves, Randall R. and Stewart, Brent S. and Wang, Kexiong and Wei, Zhuo and Zhang, Xianfeng and Pusser, L. Todd and Richlen, Michael and Brandon, John R. and Wang, Ding",
    title = "First human-caused extinction of a cetacean species?",
    year = "2007",
    journal = "Biology Letters",
    abstract = "The Yangtze River dolphin or baiji (Lipotes vexillifer), an obligate freshwater odontocete known only from the middle-lower Yangtze River system and neighbouring Qiantang River in eastern China, has long been recognized as one of the world's rarest and most threatened mammal species. The status of the baiji has not been investigated since the late 1990s, when the surviving population was estimated to be as low as 13 individuals. An intensive six-week multi-vessel visual and acoustic survey carried out in November-December 2006, covering the entire historical range of the baiji in the main Yangtze channel, failed to find any evidence that the species survives. We are forced to conclude that the baiji is now likely to be extinct, probably due to unsustainable by-catch in local fisheries. This represents the first global extinction of a large vertebrate for over 50 years, only the fourth disappearance of an entire mammal family since AD 1500, and the first cetacean species to be driven to extinction by human activity. Immediate and extreme measures may be necessary to prevent the extinction of other endangered cetaceans, including the sympatric Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis).",
    url = "https://doi.org/10.1098/rsbl.2007.0292",
    doi = "10.1098/rsbl.2007.0292",
    openalex = "W2135547714",
    references = "doi101006jmsc20011159, doi101007978147575202113, doi1010160967065395917783, doi101016096706539591782y, doi101073pnas121139198, doi101111j13652907200600088x, doi101198jasa2007s192, doi101371journalpone0000296, doi102305iucnch2003sscap2en, openalexw2125086046"
}

ABSTRACT Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of ≥8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2%) or pairs (24.6%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. Compared with historical catches, the Antarctic (‘true’) subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales. South‐east Pacific blue whales have a discrete distribution and high sighting rates compared with the Antarctic. Further work is needed to clarify their subspecific status given their distinctive genetics, acoustics and length frequencies. Antarctic blue whales numbered 1700 (95% Bayesian interval 860–2900) in 1996 (less than 1% of original levels), but are increasing at 7.3% per annum (95% Bayesian interval 1.4–11.6%). The status of other populations in the Southern Hemisphere and northern Indian Ocean is unknown because few abundance estimates are available, but higher recent sighting rates suggest that they are less depleted than Antarctic blue whales.

@article{doi101111j13652907200700106x,
    author = "Branch, Trevor A. and Stafford, Kathleen M. and Palacios, Daniel M. and Allison, Cherry and Bannister, J. L. and Burton, Chris and Cabrera, Elsa and Carlson, Carole and Vernazzani, Bárbara Galletti and Gill, Peter C. and Hucke‐Gaete, Rodrigo and Jenner, K. Curt S. and Jenner, Micheline and Matsuoka, Koji and Mikhalev, Y. A. and Miyashita, Tomio and Morrice, Margie and Nishiwaki, S and Sturrock, Vanessa and Tormosov, Dmitriy D. and Anderson, Robert C. and Baker, Alan N. and Best, PB and Borsa, Philippe and Brownell, Robert L. and Childerhouse, Simon and Findlay, Ken and Gerrodette, Tim and Ilangakoon, Anoukchika D. and Joergensen, Morten and Kahn, Benjamin and Ljungblad, Don and Maughan, Ben C. and McCauley, Robert D. and McKay, Shannon and Norris, TF and Rankin, Shannon and Samaran, Flore and Thiele, Deborah and Waerebeek, Koen Van and Warneke, Robert M.",
    title = "Past and present distribution, densities and movements of blue whales Balaenoptera musculus in the Southern Hemisphere and northern Indian Ocean",
    year = "2007",
    journal = "Mammal Review",
    abstract = "ABSTRACT Blue whale locations in the Southern Hemisphere and northern Indian Ocean were obtained from catches (303 239), sightings (4383 records of ≥8058 whales), strandings (103), Discovery marks (2191) and recoveries (95), and acoustic recordings. Sighting surveys included 7 480 450 km of effort plus 14 676 days with unmeasured effort. Groups usually consisted of solitary whales (65.2\%) or pairs (24.6\%); larger feeding aggregations of unassociated individuals were only rarely observed. Sighting rates (groups per 1000 km from many platform types) varied by four orders of magnitude and were lowest in the waters of Brazil, South Africa, the eastern tropical Pacific, Antarctica and South Georgia; higher in the Subantarctic and Peru; and highest around Indonesia, Sri Lanka, Chile, southern Australia and south of Madagascar. Blue whales avoid the oligotrophic central gyres of the Indian, Pacific and Atlantic Oceans, but are more common where phytoplankton densities are high, and where there are dynamic oceanographic processes like upwelling and frontal meandering. Compared with historical catches, the Antarctic (‘true’) subspecies is exceedingly rare and usually concentrated closer to the summer pack ice. In summer they are found throughout the Antarctic; in winter they migrate to southern Africa (although recent sightings there are rare) and to other northerly locations (based on acoustics), although some overwinter in the Antarctic. Pygmy blue whales are found around the Indian Ocean and from southern Australia to New Zealand. At least four groupings are evident: northern Indian Ocean, from Madagascar to the Subantarctic, Indonesia to western and southern Australia, and from New Zealand northwards to the equator. Sighting rates are typically much higher than for Antarctic blue whales. South‐east Pacific blue whales have a discrete distribution and high sighting rates compared with the Antarctic. Further work is needed to clarify their subspecific status given their distinctive genetics, acoustics and length frequencies. Antarctic blue whales numbered 1700 (95\% Bayesian interval 860–2900) in 1996 (less than 1\% of original levels), but are increasing at 7.3\% per annum (95\% Bayesian interval 1.4–11.6\%). The status of other populations in the Southern Hemisphere and northern Indian Ocean is unknown because few abundance estimates are available, but higher recent sighting rates suggest that they are less depleted than Antarctic blue whales.",
    url = "https://doi.org/10.1111/j.1365-2907.2007.00106.x",
    doi = "10.1111/j.1365-2907.2007.00106.x",
    openalex = "W2128779859",
    references = "doi101016b9780124555211x50001, doi101016jdsr2200307015, doi1010291999jc000043, doi10102998eo00443, doi101038367108a0, doi101038nature02996, doi101111j174876921998tb00736x, doi101126science27753341956, doi103354meps289117, openalexw2131302185, openalexw2344718058, openalexw583646462"
}

Abstract Interactions between marine mammals and fisheries are a growing problem, and effective management requires assessment of the factors driving the interaction and of the impacts on fisheries. We used data from interactions between artisanal fisheries and bottlenose dolphins around the Balearic Islands to assess these factors and impacts. Observers collected data during 1,040 fishing operations over 3 yr. Location and year were important factors affecting interaction probability, with some areas showing large increases over the study period. We estimated the combined cost of catch loss and net damage as 6.5% of the total catch value (95% CI −12.3%, −1.6%), and the annual loss to be 3.4% (95% CI −6.5%, −0.1%) of the total catch by weight. This weight equates to the dietary needs of ∼12 dolphins (95% CI 0.2, 22), suggesting the fishery is not a vital food source for the dolphin population. Two dolphins died through entanglement during the observed fishing operations. We observed 3% of the total fishing activity, by weight, in 2003; scaling up this mortality directly suggests that as many as sixty dolphins may be dying in nets each year. This interaction likely has serious conservation implications for the dolphin population.

@article{doi101111j17487692200700164x,
    author = "Brotons, José María and Grau, Antonio María and Rendell, Luke",
    title = "Estimating the impact of interactions between bottlenose dolphins and artisanal fisheries around the Balearic Islands",
    year = "2007",
    journal = "Marine Mammal Science",
    abstract = "Abstract Interactions between marine mammals and fisheries are a growing problem, and effective management requires assessment of the factors driving the interaction and of the impacts on fisheries. We used data from interactions between artisanal fisheries and bottlenose dolphins around the Balearic Islands to assess these factors and impacts. Observers collected data during 1,040 fishing operations over 3 yr. Location and year were important factors affecting interaction probability, with some areas showing large increases over the study period. We estimated the combined cost of catch loss and net damage as 6.5\% of the total catch value (95\% CI −12.3\%, −1.6\%), and the annual loss to be 3.4\% (95\% CI −6.5\%, −0.1\%) of the total catch by weight. This weight equates to the dietary needs of ∼12 dolphins (95\% CI 0.2, 22), suggesting the fishery is not a vital food source for the dolphin population. Two dolphins died through entanglement during the observed fishing operations. We observed 3\% of the total fishing activity, by weight, in 2003; scaling up this mortality directly suggests that as many as sixty dolphins may be dying in nets each year. This interaction likely has serious conservation implications for the dolphin population.",
    url = "https://doi.org/10.1111/j.1748-7692.2007.00164.x",
    doi = "10.1111/j.1748-7692.2007.00164.x",
    openalex = "W2167482417",
    references = "doi1010160967065396842815"
}

This volume presents a sweeping picture of what we know about the natural history, biology, and ecology of whales in the broad context of the dynamics of ocean ecosystems. The book encompasses multiple points of view to consider the total ecological impact of industrial whaling on the world's oceans. Combining empirical research, ecological theory and modelling, and historical data, the chapters present perspectives from ecology, population biology, physiology, genetics, evolutionary history, ocean biogeography, economics, culture, and law, among other disciplines. Throughout, chapoters investigate how whaling fundamentally disrupted ocean ecosystems, examine the various roles whales play in food webs, and discuss the continuing ecological chain reactions to the depletion of these large animals. In addition to reviewing what is known of the current and historic whale populations, this book considers how this knowledge will bear on scientific approaches to conservation and whaling in the future and provocatively asks whether it is possible to restore ocean ecosystems to their pre-whaling condition.

@book{doi101525california97805202488470010001,
    title = "Whales, Whaling, and Ocean Ecosystems",
    year = "2007",
    abstract = "This volume presents a sweeping picture of what we know about the natural history, biology, and ecology of whales in the broad context of the dynamics of ocean ecosystems. The book encompasses multiple points of view to consider the total ecological impact of industrial whaling on the world's oceans. Combining empirical research, ecological theory and modelling, and historical data, the chapters present perspectives from ecology, population biology, physiology, genetics, evolutionary history, ocean biogeography, economics, culture, and law, among other disciplines. Throughout, chapoters investigate how whaling fundamentally disrupted ocean ecosystems, examine the various roles whales play in food webs, and discuss the continuing ecological chain reactions to the depletion of these large animals. In addition to reviewing what is known of the current and historic whale populations, this book considers how this knowledge will bear on scientific approaches to conservation and whaling in the future and provocatively asks whether it is possible to restore ocean ecosystems to their pre-whaling condition.",
    url = "https://doi.org/10.1525/california/9780520248847.001.0001",
    doi = "10.1525/california/9780520248847.001.0001",
    openalex = "W601979986",
    references = "doi101038367108a0"
}

Collisions with vessels are a well-documented conservation problem for some populations of large whales (LW) in the Northern Hemisphere. Less attention has been given to incidents in the Southern Hemisphere or to small cetaceans (SC) worldwide, therefore an experimental database was compiled (N=256; 119 LW, 137 SC) to allow a rapid assessment. Confirmed collision records were identified for 25 species (7 LW, 18 SC) and unconfirmed but probable records for 10 other species (2 LW, 8 SC). Among LW, ship-caused mortality and traumatic injuries seem to affect primarily southern right (56 reported cases), humpback (15) and Bryde's whales (13), but also sperm (8), blue (5), sei (4) and fin whales (2) are involved, and probably Antarctic minke and dwarf minke whales. Southern right whale populations off South Africa and off eastern South America (Brazil, Uruguay and Argentina) suffer significant mortality. Incidence and potential population impact vary widely among the 26 small cetacean species for which collision records exist. Vessel strikes in at least two populations each of the Indo-Pacific humpback dolphin (Xiamen and Hong Kong/Pearl River, possibly western Taiwan), Irrawaddy dolphin (Mahakam River, Chilika Lagoon, possibly Laos) and finless porpoise (Yangtze River, Hong Kong) may directly compromise long-term survival. Annual vessel-caused mortality (min. 2.9% of population) for Irrawaddy dolphins in the Mahakam River may not be sustainable. The quasi-extinction of the baiji warns for a potential similar fate for the Yangtze River finless porpoise and Ganges river dolphin. Two calves of the endangered Hector's dolphin are known killed by boats. All highly impacted species have a neritic, estuarine or fluviatile habitat, areas where vessel traffic is concentrated. Species that may receive a moderate impact from collisions but which may be sustainable at species level (because many strikes are nonlethal), include common bottlenose dolphins, killer whales, short-finned pilot whales and pygmy sperm whales. Almost 2% of common bottlenose dolphins in the Gulf of Guayaquil showed propeller-inflicted injuries and scars. Propeller guards should be made compulsory for all boat-based cetacean tourism, as habituation to boat traffic seems a contributing factor in accidents. Low impact occurs in 15 small cetacean species with only few reported vessel strikes. However, vast underreporting is thought to be the norm and there is a need for a global, standardised database.

@article{doi105597lajam00109,
    author = "Waerebeek, Koen Van and Baker, Alan N. and Félix, Fernando and Gedamke, Jason and Íñiguez, Miguel A. and Sanino, Gian Paolo and Secchi, Eduardo R. and Sutaria, Dipani and van Helden, Anton and Wang, Y.",
    title = "Vessel collisions with small cetaceans worldwide and with large whales in the Southern Hemisphere, an initial assessment",
    year = "2007",
    journal = "Latin American Journal of Aquatic Mammals",
    abstract = "Collisions with vessels are a well-documented conservation problem for some populations of large whales (LW) in the Northern Hemisphere. Less attention has been given to incidents in the Southern Hemisphere or to small cetaceans (SC) worldwide, therefore an experimental database was compiled (N=256; 119 LW, 137 SC) to allow a rapid assessment. Confirmed collision records were identified for 25 species (7 LW, 18 SC) and unconfirmed but probable records for 10 other species (2 LW, 8 SC). Among LW, ship-caused mortality and traumatic injuries seem to affect primarily southern right (56 reported cases), humpback (15) and Bryde's whales (13), but also sperm (8), blue (5), sei (4) and fin whales (2) are involved, and probably Antarctic minke and dwarf minke whales. Southern right whale populations off South Africa and off eastern South America (Brazil, Uruguay and Argentina) suffer significant mortality. Incidence and potential population impact vary widely among the 26 small cetacean species for which collision records exist. Vessel strikes in at least two populations each of the Indo-Pacific humpback dolphin (Xiamen and Hong Kong/Pearl River, possibly western Taiwan), Irrawaddy dolphin (Mahakam River, Chilika Lagoon, possibly Laos) and finless porpoise (Yangtze River, Hong Kong) may directly compromise long-term survival. Annual vessel-caused mortality (min. 2.9\% of population) for Irrawaddy dolphins in the Mahakam River may not be sustainable. The quasi-extinction of the baiji warns for a potential similar fate for the Yangtze River finless porpoise and Ganges river dolphin. Two calves of the endangered Hector's dolphin are known killed by boats. All highly impacted species have a neritic, estuarine or fluviatile habitat, areas where vessel traffic is concentrated. Species that may receive a moderate impact from collisions but which may be sustainable at species level (because many strikes are nonlethal), include common bottlenose dolphins, killer whales, short-finned pilot whales and pygmy sperm whales. Almost 2\% of common bottlenose dolphins in the Gulf of Guayaquil showed propeller-inflicted injuries and scars. Propeller guards should be made compulsory for all boat-based cetacean tourism, as habituation to boat traffic seems a contributing factor in accidents. Low impact occurs in 15 small cetacean species with only few reported vessel strikes. However, vast underreporting is thought to be the norm and there is a need for a global, standardised database.",
    url = "https://doi.org/10.5597/lajam00109",
    doi = "10.5597/lajam00109",
    openalex = "W2020715471",
    references = "doi101002jcu1870140619, doi101016jmarpolbul200603014, doi101098rsbl20070292, doi101111j13652907200700106x, doi101111j17487692200600098x, doi101578am3012004111, doi102305iucnch2003sscap2en, doi1047536jcrmvi288, doi105860choice382743, openalexw1529948115, openalexw565618124"
}

Contributors Foreword The Mammal Research Institute Acknowledgements Introduction Map of the subregion The cetacean environment off southern Africa Isabelle Ansorge and Johann Lutjeharms The South African species gate William Perrin A classification of living cetacea Keys to the whales, dolphins and porpoise of the region Anatomy of cetacean skulls Species accounts BALAENIDAE: Southern right whale, Eubalaena australis NEOBALAENIDAE: Pygmy right whale, Caperea marginata BALAENOPTERIDAE: Humpback whale, Megaptera novaeangliae Antarctic minke whale, Balaenoptera bonaerensis Dwarf minke whale, B. acutorostrata subsp. Bryde's whale, B. brydei Sei whale, B. borealis Fin whale, B. physalus Blue whale, B. musculus PHYSETERIDAE: Sperm whale, Physeter macrocephalus KOGIIDAE: Pygmy sperm whale, Kogia breviceps Dwarf sperm whale, K. sima ZIPHIIDAE: Cuvier's beaked whale, Ziphius cavirostris Arnoux's beaked whale, Berardius arnuxii Shepherd's beaked whale, Tasmacetus shepherdi Longman's beaked whale, Indopacetus pacificus Southern bottlenose whale, Hyperoodon planifrons Hector's beaked whale, Mesoplodon hectori True's beaked whale, M. mirus Gervais' beaked whale, M. europaeus Gray's beaked whale, M. grayi Andrews' beaked whale, M. bowdoini Layard's beaked whale, M. layardii Blainville's beaked whale, M. densirostris Ginkgo-toothed beaked whale, M. ginkgodens DELPHINIDAE: Heaviside's dolphin, Cephalorhynchus heavisidii Commerson's dolphin, C. commersonii Rough-toothed dolphin, Steno bredanensis Atlantic humpback dolphin, Sousa teuszi Indian humpback dolphin, S. chinensis Common bottlenose dolphin, Tursiops truncates Indian Ocean bottlenose dolphin, T. aduncus Pantropical spotted dolphin, Stenella attenuate Atlantic spotted dolphin, S. frontalis Spinner dolphin, S. longirostris Clymene dolphin, S. clymene Striped dolphin, S. coeruleoalba Short-beaked common dolphin, Delphinus delphis Long-beaked common dolphin, D. capensis Fraser's dolphin, Lagenodelphis hosei Dusky dolphin, Lagenorhynchus obscurus Hourglass dolphin, L. cruciger Southern right whale dolphin, Lissodelphis peronii Risso's dolphin, Grampus griseus Melon-headed whale, Peponocephala electra Pygmy killer whale, Feresa attenuate False killer whale, Pseudorca crassidens Killer whale, Orcinus orca Long-finned pilot whale, Globicephala melas Short-finned pilot whale, G. macrorhynchus PHOCOENIDAE: Spectacled porpoise, Phocoena dioptrica Bibliography Glossary Photographic acknowledgements Index List of subscribers.

@book{openalexw565618124,
    author = "Best, Peter B. and Folkens, Pieter A.",
    title = "Whales and dolphins of the Southern African subregion",
    year = "2007",
    journal = "Medical Entomology and Zoology",
    abstract = "Contributors Foreword The Mammal Research Institute Acknowledgements Introduction Map of the subregion The cetacean environment off southern Africa Isabelle Ansorge and Johann Lutjeharms The South African species gate William Perrin A classification of living cetacea Keys to the whales, dolphins and porpoise of the region Anatomy of cetacean skulls Species accounts BALAENIDAE: Southern right whale, Eubalaena australis NEOBALAENIDAE: Pygmy right whale, Caperea marginata BALAENOPTERIDAE: Humpback whale, Megaptera novaeangliae Antarctic minke whale, Balaenoptera bonaerensis Dwarf minke whale, B. acutorostrata subsp. Bryde's whale, B. brydei Sei whale, B. borealis Fin whale, B. physalus Blue whale, B. musculus PHYSETERIDAE: Sperm whale, Physeter macrocephalus KOGIIDAE: Pygmy sperm whale, Kogia breviceps Dwarf sperm whale, K. sima ZIPHIIDAE: Cuvier's beaked whale, Ziphius cavirostris Arnoux's beaked whale, Berardius arnuxii Shepherd's beaked whale, Tasmacetus shepherdi Longman's beaked whale, Indopacetus pacificus Southern bottlenose whale, Hyperoodon planifrons Hector's beaked whale, Mesoplodon hectori True's beaked whale, M. mirus Gervais' beaked whale, M. europaeus Gray's beaked whale, M. grayi Andrews' beaked whale, M. bowdoini Layard's beaked whale, M. layardii Blainville's beaked whale, M. densirostris Ginkgo-toothed beaked whale, M. ginkgodens DELPHINIDAE: Heaviside's dolphin, Cephalorhynchus heavisidii Commerson's dolphin, C. commersonii Rough-toothed dolphin, Steno bredanensis Atlantic humpback dolphin, Sousa teuszi Indian humpback dolphin, S. chinensis Common bottlenose dolphin, Tursiops truncates Indian Ocean bottlenose dolphin, T. aduncus Pantropical spotted dolphin, Stenella attenuate Atlantic spotted dolphin, S. frontalis Spinner dolphin, S. longirostris Clymene dolphin, S. clymene Striped dolphin, S. coeruleoalba Short-beaked common dolphin, Delphinus delphis Long-beaked common dolphin, D. capensis Fraser's dolphin, Lagenodelphis hosei Dusky dolphin, Lagenorhynchus obscurus Hourglass dolphin, L. cruciger Southern right whale dolphin, Lissodelphis peronii Risso's dolphin, Grampus griseus Melon-headed whale, Peponocephala electra Pygmy killer whale, Feresa attenuate False killer whale, Pseudorca crassidens Killer whale, Orcinus orca Long-finned pilot whale, Globicephala melas Short-finned pilot whale, G. macrorhynchus PHOCOENIDAE: Spectacled porpoise, Phocoena dioptrica Bibliography Glossary Photographic acknowledgements Index List of subscribers.",
    openalex = "W565618124"
}

ABSTRACT Bottlenose dolphins Tursiops truncatus are amongst the best‐known cetaceans. In the Mediterranean Sea, however, modern field studies of cetaceans did not start until the late 1980s. Bottlenose dolphins have been studied only in relatively small portions of the basin, and wide areas remain largely unexplored. This paper reviews the ecology, behaviour, interactions with fisheries and conservation status of Mediterranean bottlenose dolphins, and identifies threats likely to have affected them in historical and recent times. Whilst intentional killing was probably the most important cause of mortality until the 1960s, important ongoing threats include incidental mortality in fishing gear and the reduced availability of key prey caused by overfishing and environmental degradation throughout the region. Additional potential or likely threats include the toxic effects of xenobiotic chemicals, epizootic outbreaks, direct disturbance from boating and shipping, noise, and the consequences of climate change. The flexible social organization and opportunistic diet and behaviour of bottlenose dolphins may allow them to withstand at least some of the effects of overfishing and habitat degradation. However, dolphin abundance is thought to have declined considerably in the region and management measures are needed to prevent further decline. Management strategies that could benefit bottlenose dolphins, such as sustainable fishing, curbing marine pollution and protecting biodiversity, are already embedded in legislation and treaties. Compliance with those existing commitments and obligations should be given high priority.

@article{doi101111j13652907200800133x,
    author = "Bearzi, Giovanni and Fortuna, Caterina Maria and Reeves, Randall R.",
    title = "Ecology and conservation of common bottlenose dolphins Tursiops truncatus in the Mediterranean Sea",
    year = "2008",
    journal = "Mammal Review",
    abstract = "ABSTRACT Bottlenose dolphins Tursiops truncatus are amongst the best‐known cetaceans. In the Mediterranean Sea, however, modern field studies of cetaceans did not start until the late 1980s. Bottlenose dolphins have been studied only in relatively small portions of the basin, and wide areas remain largely unexplored. This paper reviews the ecology, behaviour, interactions with fisheries and conservation status of Mediterranean bottlenose dolphins, and identifies threats likely to have affected them in historical and recent times. Whilst intentional killing was probably the most important cause of mortality until the 1960s, important ongoing threats include incidental mortality in fishing gear and the reduced availability of key prey caused by overfishing and environmental degradation throughout the region. Additional potential or likely threats include the toxic effects of xenobiotic chemicals, epizootic outbreaks, direct disturbance from boating and shipping, noise, and the consequences of climate change. The flexible social organization and opportunistic diet and behaviour of bottlenose dolphins may allow them to withstand at least some of the effects of overfishing and habitat degradation. However, dolphin abundance is thought to have declined considerably in the region and management measures are needed to prevent further decline. Management strategies that could benefit bottlenose dolphins, such as sustainable fishing, curbing marine pollution and protecting biodiversity, are already embedded in legislation and treaties. Compliance with those existing commitments and obligations should be given high priority.",
    url = "https://doi.org/10.1111/j.1365-2907.2008.00133.x",
    doi = "10.1111/j.1365-2907.2008.00133.x",
    openalex = "W2009349670",
    references = "doi101002aqc855, doi101016c20090022533, doi101016s0169534700891715, doi101038nature01017, doi101038nature01286, doi101126science1059199, doi101126science1132294, doi101126science2795352860, doi1012019781420050943ch7, doi101260095830507781076194, doi102305iucnch2003sscap2en, openalexw2939474406"
}

In this study, we present for the first time a model for the social structure of Risso’s dolphins (Grampus griseus Cuvier, 1812). Over the period 2004–2006, 1028 Risso’s dolphins were identified at Pico island, Azores. Individuals sighted on 10 or more occasions were included in the analysis of social structure (n = 183). High resighting rates indicate strong site fidelity for at least part of the population. We found that individuals form stable, long-term bonds organised in pairs or in clusters of 3–12 individuals. Social structure is stratified based on age and sex classes, with strong associations between adult males and between adult females. We suggest that clusters form the basic units of Risso’s dolphin society. Thirteen pods consisting solely of adults, likely males, and 3 pods consisting of mother–calf pairs were identified. Males are organised in stable, long-term associations of varying size that occur throughout the complete range of behavioural states observed. For females, associations can be of similar strength, but the time scale may vary depending on the presence of nursing calves. As subadults, associations also occur (pair formation), but are less stable than those observed for adults. We propose a new model for Risso’s dolphin societies known as a stratified social organisation, which differs from the fission–fusion and matrilineal society models.

@article{doi101139z07138,
    author = "Hartman, Karin L. and Visser, Fleur and Hendriks, Arthur J. E.",
    title = "Social structure of Risso’s dolphins (Grampus griseus) at the Azores: a stratified community based on highly associated social units",
    year = "2008",
    journal = "Canadian Journal of Zoology",
    abstract = "In this study, we present for the first time a model for the social structure of Risso’s dolphins (Grampus griseus Cuvier, 1812). Over the period 2004–2006, 1028 Risso’s dolphins were identified at Pico island, Azores. Individuals sighted on 10 or more occasions were included in the analysis of social structure (n = 183). High resighting rates indicate strong site fidelity for at least part of the population. We found that individuals form stable, long-term bonds organised in pairs or in clusters of 3–12 individuals. Social structure is stratified based on age and sex classes, with strong associations between adult males and between adult females. We suggest that clusters form the basic units of Risso’s dolphin society. Thirteen pods consisting solely of adults, likely males, and 3 pods consisting of mother–calf pairs were identified. Males are organised in stable, long-term associations of varying size that occur throughout the complete range of behavioural states observed. For females, associations can be of similar strength, but the time scale may vary depending on the presence of nursing calves. As subadults, associations also occur (pair formation), but are less stable than those observed for adults. We propose a new model for Risso’s dolphin societies known as a stratified social organisation, which differs from the fission–fusion and matrilineal society models.",
    url = "https://doi.org/10.1139/z07-138",
    doi = "10.1139/z07-138",
    openalex = "W2153746697",
    references = "doi101111j174876921998tb00736x"
}

A short term survey to quantify the number of marine mammals incidentally caught, and interviews to gain perceptions of local fishers towards issues of by-catch, were conducted. A total of 44 cetaceans was recorded as incidental catches at Chennai, Kakinada and Mangalore fishing harbours during 80 days of observation. Six species of dolphins and one species of porpoise were recorded. The spinner dolphin Stenella longirostris was the most frequently caught (38.6%), followed by the finless porpoise Neophocaena phocaenoides (31.8%). Gill-nets and purse seines operated from motorized boats accounted for the entire by-catch. It is estimated that 9000–10,000 cetaceans are killed by gill-nets every year along the Indian coast. The intricacies and possibilities of reducing cetacean kills by gill-nets are discussed in this paper.

@article{doi101017s175526720900075x,
    author = "Yousuf, K S S M and Anoop, Ambili and Anoop, B. K. and Afsal, V.V. and Vivekanandan, E and Kumarran, R. P. and Rajagopalan, M. and Krishnakumar, P K and Jayasankar, P.",
    title = "Observations on incidental catch of cetaceans in three landing centres along the Indian coast",
    year = "2009",
    journal = "Marine Biodiversity Records",
    abstract = "A short term survey to quantify the number of marine mammals incidentally caught, and interviews to gain perceptions of local fishers towards issues of by-catch, were conducted. A total of 44 cetaceans was recorded as incidental catches at Chennai, Kakinada and Mangalore fishing harbours during 80 days of observation. Six species of dolphins and one species of porpoise were recorded. The spinner dolphin Stenella longirostris was the most frequently caught (38.6\%), followed by the finless porpoise Neophocaena phocaenoides (31.8\%). Gill-nets and purse seines operated from motorized boats accounted for the entire by-catch. It is estimated that 9000–10,000 cetaceans are killed by gill-nets every year along the Indian coast. The intricacies and possibilities of reducing cetacean kills by gill-nets are discussed in this paper.",
    url = "https://doi.org/10.1017/s175526720900075x",
    doi = "10.1017/s175526720900075x",
    openalex = "W2113685439"
}

Abstract This study examined the population of Indo‐Pacific humpback dolphins, Sousa chinensis, inhabiting the Great Sandy Strait Marine Park, Queensland, Australia. A total of 106 dolphins were identified during 228 boat‐based surveys, completed between April 2004 and April 2007. Based on the distribution of resighted individuals and the pattern of associations, it was established that this population consists of two largely geographically distinct communities, referred to as the Northern Community (NC) and the Southern Community (SC). The only recorded interaction between the two groups was a single pod composed of one member of the NC and 11 dolphins from the SC. Abundance was estimated for the entire population and by geographical area using open population models. Estimates for the Great Sandy Strait indicate that about 150 dolphins (N GSS = 148.4, SE = 8.3, 95% CI: 132.5–165.2) used this area during the study. The NC and SC total population sizes was estimated to be 76 (N NGSS = 75.80, SE = 3.88, 95% CI = 71–86) and 75 (N SGSS = 74.98, SE = 4.43, 95% CI: 66–83), respectively. Analysis of residence patterns indicates that a majority of the identified dolphins are long‐term residents.

@article{doi101111j17487692200900296x,
    author = "Cagnazzi, Daniele and Harrison, Peter L. and Ross, G. J. B. and Lynch, Peter",
    title = "Abundance and site fidelity of Indo‐Pacific Humpback dolphins in the Great Sandy Strait, Queensland, Australia",
    year = "2009",
    journal = "Marine Mammal Science",
    abstract = "Abstract This study examined the population of Indo‐Pacific humpback dolphins, Sousa chinensis, inhabiting the Great Sandy Strait Marine Park, Queensland, Australia. A total of 106 dolphins were identified during 228 boat‐based surveys, completed between April 2004 and April 2007. Based on the distribution of resighted individuals and the pattern of associations, it was established that this population consists of two largely geographically distinct communities, referred to as the Northern Community (NC) and the Southern Community (SC). The only recorded interaction between the two groups was a single pod composed of one member of the NC and 11 dolphins from the SC. Abundance was estimated for the entire population and by geographical area using open population models. Estimates for the Great Sandy Strait indicate that about 150 dolphins (N GSS = 148.4, SE = 8.3, 95\% CI: 132.5–165.2) used this area during the study. The NC and SC total population sizes was estimated to be 76 (N NGSS = 75.80, SE = 3.88, 95\% CI = 71–86) and 75 (N SGSS = 74.98, SE = 4.43, 95\% CI: 66–83), respectively. Analysis of residence patterns indicates that a majority of the identified dolphins are long‐term residents.",
    url = "https://doi.org/10.1111/j.1748-7692.2009.00296.x",
    doi = "10.1111/j.1748-7692.2009.00296.x",
    openalex = "W2055655547",
    references = "doi101578am3012004125"
}

The Indo-Pacific humpback dolphin (Sousa chinensis Osbeck, 1765) is a threatened species inhabiting the waters of China. Despite being of conservation concern, the distribution and abundance of this species has not been comprehensively evaluated. From 1994 to 2008 we performed over 14 000 km of line-transect surveys and administered over 700 questionnaires to collect basic information on the geographic range and likely abundance of Indo-Pacific humpback dolphins along the southern and eastern coasts of China. Through our study we were able to establish a reporting network of stranding and incidental catches for this species. Our quantitative data suggests that only 76 animals remain around Xiamen, 39 in the Hepu Nature Reserve and 114 in the estuary of the Dafengjiang River. Qualitative data from local fishing people and government officials suggests that dolphins may exist year-round in waters off Ningde and Shantou. We found that wild populations of Sousa chinensis in this important region are clearly being affected by human disturbance and habitat deterioration, including underwater blasting, vessel collision, fishing, aquaculture and water pollution. Although some protected areas have been established and this species is protected under Chinese law, there remains virtually no protection for this animal.

@article{doi101111j17494877200900160x,
    author = "Chen, Bingyao and Zheng, Dongmei and Yang, Guang and Xu, Xinrong and Zhou, Kaiya",
    title = "Distribution and conservation of the Indo–Pacific humpback dolphin in China",
    year = "2009",
    journal = "Integrative Zoology",
    abstract = "The Indo-Pacific humpback dolphin (Sousa chinensis Osbeck, 1765) is a threatened species inhabiting the waters of China. Despite being of conservation concern, the distribution and abundance of this species has not been comprehensively evaluated. From 1994 to 2008 we performed over 14 000 km of line-transect surveys and administered over 700 questionnaires to collect basic information on the geographic range and likely abundance of Indo-Pacific humpback dolphins along the southern and eastern coasts of China. Through our study we were able to establish a reporting network of stranding and incidental catches for this species. Our quantitative data suggests that only 76 animals remain around Xiamen, 39 in the Hepu Nature Reserve and 114 in the estuary of the Dafengjiang River. Qualitative data from local fishing people and government officials suggests that dolphins may exist year-round in waters off Ningde and Shantou. We found that wild populations of Sousa chinensis in this important region are clearly being affected by human disturbance and habitat deterioration, including underwater blasting, vessel collision, fishing, aquaculture and water pollution. Although some protected areas have been established and this species is protected under Chinese law, there remains virtually no protection for this animal.",
    url = "https://doi.org/10.1111/j.1749-4877.2009.00160.x",
    doi = "10.1111/j.1749-4877.2009.00160.x",
    openalex = "W2086299454",
    references = "doi1015159789882200159016"
}

Joanne O'Brien, Simon Berrow, David McGrath, Peter Evans, CETACEANS IN IRISH WATERS: A REVIEW OF RECENT RESEARCH, Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 109B, No. 2 (September 2009), pp. 63-88

@article{doi103318bioe2009109263,
    author = "O’Brien, Joanne and Berrow, Simon and McGrath, David and Evans, Peter G. H.",
    title = "CETACEANS IN IRISH WATERS: A REVIEW OF RECENT RESEARCH",
    year = "2009",
    journal = "Biology \& Environment Proceedings of the Royal Irish Academy",
    abstract = "Joanne O'Brien, Simon Berrow, David McGrath, Peter Evans, CETACEANS IN IRISH WATERS: A REVIEW OF RECENT RESEARCH, Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 109B, No. 2 (September 2009), pp. 63-88",
    url = "https://doi.org/10.3318/bioe.2009.109.2.63",
    doi = "10.3318/bioe.2009.109.2.63",
    openalex = "W2014950976",
    references = "openalexw2546754148"
}

We reviewed prominent emerging infectious diseases of cetaceans, examined their potential to impact populations, re-assessed zoonotic risk and evaluated the role of environmental stressors. Cetacean morbilliviruses and papillomaviruses as well as Brucella spp. and Toxoplasma gondii are thought to interfere with population abundance by inducing high mortalities, lowering reproductive success or by synergistically increasing the virulence of other diseases. Severe cases of lobomycosis and lobomycosis-like disease (LLD) may contribute to the death of some dolphins. The zoonotic hazard of marine mammal brucellosis and toxoplasmosis may have been underestimated, attributable to frequent misdiagnoses and underreporting, particularly in developing countries and remote areas where carcass handling without protective gear and human consumption of fresh cetacean products are commonplace. Environmental factors seem to play a role in the emergence and pathogenicity of morbillivirus epidemics, lobomycosis/LLD, toxoplasmosis, poxvirus-associated tattoo skin disease and, in harbour porpoises, infectious diseases of multifactorial aetiology. Inshore and estuarine cetaceans incur higher risks than pelagic cetaceans due to habitats often severely altered by anthropogenic factors such as chemical and biological contamination, direct and indirect fisheries interactions, traumatic injuries from vessel collisions and climate change.

@article{doi103354dao02101,
    author = "Bressem, MF Van and Raga, Juan Antonio and Guardo, Giovanni Di and Jepson, PD and Duignan, PJ and Siebert, Ursula and Barrett, T. and Santos, MCdO and Moreno, IB and Siciliano, Salvatore and Aguilar, Álex and Waerebeek, Koen Van",
    title = "Emerging infectious diseases in cetaceans worldwide and the possible role of environmental stressors",
    year = "2009",
    journal = "Diseases of Aquatic Organisms",
    abstract = "We reviewed prominent emerging infectious diseases of cetaceans, examined their potential to impact populations, re-assessed zoonotic risk and evaluated the role of environmental stressors. Cetacean morbilliviruses and papillomaviruses as well as Brucella spp. and Toxoplasma gondii are thought to interfere with population abundance by inducing high mortalities, lowering reproductive success or by synergistically increasing the virulence of other diseases. Severe cases of lobomycosis and lobomycosis-like disease (LLD) may contribute to the death of some dolphins. The zoonotic hazard of marine mammal brucellosis and toxoplasmosis may have been underestimated, attributable to frequent misdiagnoses and underreporting, particularly in developing countries and remote areas where carcass handling without protective gear and human consumption of fresh cetacean products are commonplace. Environmental factors seem to play a role in the emergence and pathogenicity of morbillivirus epidemics, lobomycosis/LLD, toxoplasmosis, poxvirus-associated tattoo skin disease and, in harbour porpoises, infectious diseases of multifactorial aetiology. Inshore and estuarine cetaceans incur higher risks than pelagic cetaceans due to habitats often severely altered by anthropogenic factors such as chemical and biological contamination, direct and indirect fisheries interactions, traumatic injuries from vessel collisions and climate change.",
    url = "https://doi.org/10.3354/dao02101",
    doi = "10.3354/dao02101",
    openalex = "W1974062751",
    references = "doi105597lajam00109"
}

Global climate change has already resulted in an increase in oceanic water temperatures in some areas and is predicted to lead to further increases throughout much of the world in the foreseeable future. One possible response of cetacean species to these increases in water temperature is that species' ranges may change. Here, I provide a framework for assessing which cetacean species' ranges are likely to change as a result of increases in water temperature and whether they will expand, shift poleward or contract based on their current distributions. Based on this framework, it is predicted that the ranges of 88% of cetaceans may be affected by changes in water temperature resulting from global climate change. For 47% of species, these changes are anticipated to have unfavourable implications for their conservation, and for 21% the changes may put at least one geographically isolated population of the species at high risk of extinction. This framework suggests that certain characteristics put some species at greater risk from such changes than others. These include a range that is restricted to non-tropical waters (including temperate species) and a preference for shelf waters. These characteristics are shared by most porpoises and Lagenorhynchus species and by all members of the genus Cephalorhynchus. As a result, species in these taxa are potentially at particular risk from changes in range in response to increasing water temperatures. However, further research is required to assess whether these predictions are, indeed, correct.

@article{doi103354esr00197,
    author = "MacLeod, CD",
    title = "Global climate change, range changes and potential implications for the conservation of marine cetaceans: a review and synthesis",
    year = "2009",
    journal = "Endangered Species Research",
    abstract = "Global climate change has already resulted in an increase in oceanic water temperatures in some areas and is predicted to lead to further increases throughout much of the world in the foreseeable future. One possible response of cetacean species to these increases in water temperature is that species' ranges may change. Here, I provide a framework for assessing which cetacean species' ranges are likely to change as a result of increases in water temperature and whether they will expand, shift poleward or contract based on their current distributions. Based on this framework, it is predicted that the ranges of 88\% of cetaceans may be affected by changes in water temperature resulting from global climate change. For 47\% of species, these changes are anticipated to have unfavourable implications for their conservation, and for 21\% the changes may put at least one geographically isolated population of the species at high risk of extinction. This framework suggests that certain characteristics put some species at greater risk from such changes than others. These include a range that is restricted to non-tropical waters (including temperate species) and a preference for shelf waters. These characteristics are shared by most porpoises and Lagenorhynchus species and by all members of the genus Cephalorhynchus. As a result, species in these taxa are potentially at particular risk from changes in range in response to increasing water temperatures. However, further research is required to assess whether these predictions are, indeed, correct.",
    url = "https://doi.org/10.3354/esr00197",
    doi = "10.3354/esr00197",
    openalex = "W2028472174",
    references = "doi101016016953479390043o, doi101016s0169534799017644, doi10103835842, doi101038nature01286, doi101038nature02121, doi101126science1071329, doi101126science1111322, doi101126science28754612225, doi101146annurevecolsys36102803095431, doi102305iucnch2003sscap2en, openalexw583646462"
}

@incollection{crossref2010cetaceans,
    title = "Cetaceans",
    year = "2010",
    booktitle = "Lyster's International Wildlife Law",
    url = "https://doi.org/10.1017/cbo9780511975301.008",
    doi = "10.1017/cbo9780511975301.008",
    pages = "150-198"
}

Abstract To obtain critical information on distribution and abundance of Indo-Pacific humpback dolphins (Sousa chinensis) residing in the Pearl River Estuary (PRE), systematic line-transect surveys and photo-identification studies were conducted in the eastern and western sections of the estuary in 2005–2006 and 2007–2008, respectively. Dolphins in the eastern section occurred throughout Lingding Bay, whereas their distribution in the western section extended from the mouth of Modaomen to the channel between Shangchuan and Xiachuan islands. Variations in dolphin distribution during the wet and dry seasons were evident and probably associated with movements of their prey species. Photo-identification of individuals confirmed exchange of at least some individuals between the western and eastern sections of PRE, and thus dolphins from both areas almost certainly comprise a single population. Using line-transect analysis, the total population size of the PRE humpback dolphins was estimated to be 2555 during the wet season and 2517 during the dry season. However, these should be considered preliminary as the coefficients of variation in some survey areas were high. Further studies should focus on refining these estimates and working towards understanding the western boundary of the PRE population.

@article{doi101515mamm2010024,
    author = "Chen, Tao and Hung, Samuel K. and Qiu, Yongsong and Jia, Xiaoping and Jefferson, Thomas A.",
    title = "Distribution, abundance, and individual movements of Indo-Pacific humpback dolphins (Sousa chinensis) in the Pearl River Estuary, China",
    year = "2010",
    journal = "Mammalia",
    abstract = "Abstract To obtain critical information on distribution and abundance of Indo-Pacific humpback dolphins (Sousa chinensis) residing in the Pearl River Estuary (PRE), systematic line-transect surveys and photo-identification studies were conducted in the eastern and western sections of the estuary in 2005–2006 and 2007–2008, respectively. Dolphins in the eastern section occurred throughout Lingding Bay, whereas their distribution in the western section extended from the mouth of Modaomen to the channel between Shangchuan and Xiachuan islands. Variations in dolphin distribution during the wet and dry seasons were evident and probably associated with movements of their prey species. Photo-identification of individuals confirmed exchange of at least some individuals between the western and eastern sections of PRE, and thus dolphins from both areas almost certainly comprise a single population. Using line-transect analysis, the total population size of the PRE humpback dolphins was estimated to be 2555 during the wet season and 2517 during the dry season. However, these should be considered preliminary as the coefficients of variation in some survey areas were high. Further studies should focus on refining these estimates and working towards understanding the western boundary of the PRE population.",
    url = "https://doi.org/10.1515/mamm.2010.024",
    doi = "10.1515/mamm.2010.024",
    openalex = "W2033528029",
    references = "doi1016441545141020016550001sc20co2"
}

The Shannon Estuary is home to Ireland’s only known resident population of bottlenose dolphins (Tursiops truncatus) and is designated as a candidate Special Area of Conservation (cSAC) for this species. Proper conservation management of these dolphins requires an understanding of the social structure of this population. Four years of photoidentification data (2005 to 2009, excluding 2007) were used to construct sociograms that complement a cluster analysis of individually marked dolphins and their associates. The results found little evidence of social stability or group fidelity for this study’s dolphin population. Analysis of dolphins observed in consecutive years showed that the probability of group members encountering an individual dolphin in the second year did not depart from a random model. The social parameters for this resident population seem to be typical for this species. Bottlenose dolphins are found to exhibit a highly fluid, dynamic social structure within which individuals change their composition and associates regularly. These dolphins in the Shannon Estuary appear to live in a fission-fusion based society.

@article{doi101578am3642010372,
    author = "Foley, Aoife and McGrath, David and Berrow, Simon and Gerritsen, H.D.",
    title = "Social Structure Within the Bottlenose Dolphin (Tursiops truncatus) Population in the Shannon Estuary, Ireland",
    year = "2010",
    journal = "Aquatic Mammals",
    abstract = "The Shannon Estuary is home to Ireland’s only known resident population of bottlenose dolphins (Tursiops truncatus) and is designated as a candidate Special Area of Conservation (cSAC) for this species. Proper conservation management of these dolphins requires an understanding of the social structure of this population. Four years of photoidentification data (2005 to 2009, excluding 2007) were used to construct sociograms that complement a cluster analysis of individually marked dolphins and their associates. The results found little evidence of social stability or group fidelity for this study’s dolphin population. Analysis of dolphins observed in consecutive years showed that the probability of group members encountering an individual dolphin in the second year did not depart from a random model. The social parameters for this resident population seem to be typical for this species. Bottlenose dolphins are found to exhibit a highly fluid, dynamic social structure within which individuals change their composition and associates regularly. These dolphins in the Shannon Estuary appear to live in a fission-fusion based society.",
    url = "https://doi.org/10.1578/am.36.4.2010.372",
    doi = "10.1578/am.36.4.2010.372",
    openalex = "W2091096356",
    references = "openalexw2546754148"
}

The Guiana dolphin, Sotalia guianensis, is a small delphinid found in costal waters, estuaries and bays from Santa Catarina, Brazil, to Nicaragua. Strandings of Guiana dolphins were recorded systematically and opportunistically in the coast of Ceará (~02-04°S), northeastern Brazil, from 1992 to 2005. A total of 160 single events were documented. The number of records was higher in Fortaleza Metropolitan Region than in other three surveyed areas, probably due to a more intensive survey effort. More strandings were recorded during austral winter and spring. The majority of stranded animals were adults (48.8%). Calves were not commonly recovered and no seasonality in the strandings of calves was observed. Overall body length ranged from 95 to 208cm for females and from 85 to 210cm for males. A total of 49 animals (30.6%) showed evidence of fishery interactions such as net marks and cuts. Of these, we confirmed through fisherman information the incidental catch of 13 dolphins by driftnet (n = 8), surface gillnet (n = 3) and beach seine (n = 2). Twenty three percent of all stranded animals showed evidences of other human interactions, like meat or fins removed, eyes removed and rostrum extracted. According to the results, Guiana dolphin strandings occurred year-round in all zones along the coast of Ceará. The incidental bycatch in fishing nets may have a negative impact on the dolphin population. The study reveals that a long-term systematic monitoring of artisanal fishing communities is necessary to evaluate the extent of the impact on the species.

@article{doi105597lajam00157,
    author = "de Meirelles, Ana Carolina Oliveira and Ribeiro, Alexandre C. and Silva, C. P. N. and Soares-Filho, Aldeney Andrade",
    title = "Records of Guiana dolphin, Sotalia guianensis, in the State of Ceará, Northeastern Brazil",
    year = "2010",
    journal = "Latin American Journal of Aquatic Mammals",
    abstract = "The Guiana dolphin, Sotalia guianensis, is a small delphinid found in costal waters, estuaries and bays from Santa Catarina, Brazil, to Nicaragua. Strandings of Guiana dolphins were recorded systematically and opportunistically in the coast of Ceará (\textasciitilde 02-04°S), northeastern Brazil, from 1992 to 2005. A total of 160 single events were documented. The number of records was higher in Fortaleza Metropolitan Region than in other three surveyed areas, probably due to a more intensive survey effort. More strandings were recorded during austral winter and spring. The majority of stranded animals were adults (48.8\%). Calves were not commonly recovered and no seasonality in the strandings of calves was observed. Overall body length ranged from 95 to 208cm for females and from 85 to 210cm for males. A total of 49 animals (30.6\%) showed evidence of fishery interactions such as net marks and cuts. Of these, we confirmed through fisherman information the incidental catch of 13 dolphins by driftnet (n = 8), surface gillnet (n = 3) and beach seine (n = 2). Twenty three percent of all stranded animals showed evidences of other human interactions, like meat or fins removed, eyes removed and rostrum extracted. According to the results, Guiana dolphin strandings occurred year-round in all zones along the coast of Ceará. The incidental bycatch in fishing nets may have a negative impact on the dolphin population. The study reveals that a long-term systematic monitoring of artisanal fishing communities is necessary to evaluate the extent of the impact on the species.",
    url = "https://doi.org/10.5597/lajam00157",
    doi = "10.5597/lajam00157",
    openalex = "W2088470283",
    references = "openalexw2546754148"
}

SUMMARY There is currently a great deal of interest in using stable isotope methods to investigate diet, trophic level and migration in wild cetaceans. In order to correctly interpret the results stemming from these methods, it is crucial to understand how diet isotopic values are reflected in consumer tissues. In this study, we investigated patterns of isotopic discrimination between diet and blood constituents of two species of cetaceans (killer whale, Orcinus orca, and bottlenose dolphin, Tursiops truncatus) fed controlled diets over 308 and 312 days, respectively. Diet discrimination factors (Δ; mean ± s.d.) for plasma were estimated to Δ13C=2.3±0.6‰ and Δ15N=1.8±0.3‰, respectively, for both species and to Δ13C=2.7±0.3‰ and Δ15N=0.5±0.1‰ for red blood cells. Delipidation did not have a significant effect on carbon and nitrogen isotopic values of blood constituents, confirming that cetacean blood does not serve as a reservoir of lipids. In contrast, carbon isotopic values were higher in delipidated samples of blubber, liver and muscle from killer whales. The potential for conflict between fisheries and cetaceans has heightened the need for trophic information about these taxa. These results provide the first published stable isotope incorporation data for cetaceans, which are essential if conclusions are to be drawn on issues concerning trophic structures, carbon sources and diet reconstruction.

@article{caut2011stable,
    author = "Caut, Stéphane and Laran, Sophie and Garcia-Hartmann, Emmanuel and Das, Krishna",
    title = "Stable isotopes of captive cetaceans (killer whales and bottlenose dolphins)",
    year = "2011",
    journal = "Journal of Experimental Biology",
    abstract = "SUMMARY There is currently a great deal of interest in using stable isotope methods to investigate diet, trophic level and migration in wild cetaceans. In order to correctly interpret the results stemming from these methods, it is crucial to understand how diet isotopic values are reflected in consumer tissues. In this study, we investigated patterns of isotopic discrimination between diet and blood constituents of two species of cetaceans (killer whale, Orcinus orca, and bottlenose dolphin, Tursiops truncatus) fed controlled diets over 308 and 312 days, respectively. Diet discrimination factors (Δ; mean ± s.d.) for plasma were estimated to Δ13C=2.3±0.6‰ and Δ15N=1.8±0.3‰, respectively, for both species and to Δ13C=2.7±0.3‰ and Δ15N=0.5±0.1‰ for red blood cells. Delipidation did not have a significant effect on carbon and nitrogen isotopic values of blood constituents, confirming that cetacean blood does not serve as a reservoir of lipids. In contrast, carbon isotopic values were higher in delipidated samples of blubber, liver and muscle from killer whales. The potential for conflict between fisheries and cetaceans has heightened the need for trophic information about these taxa. These results provide the first published stable isotope incorporation data for cetaceans, which are essential if conclusions are to be drawn on issues concerning trophic structures, carbon sources and diet reconstruction.",
    url = "https://doi.org/10.1242/jeb.045104",
    doi = "10.1242/jeb.045104",
    number = "4",
    openalex = "W2124793589",
    pages = "538-545",
    volume = "214",
    references = "doi101007s004420031270z, doi101007s004420050865, doi101007s004420060630x, doi1010160307441278900493, doi101016jtree200409004, doi101016s0021925818648495, doi101111j13652664200901620x, doi101111j1469185x200800064x, doi101139z99165, doi1018900012965819970781271siiaea20co2"
}

@article{crossref2011declaration,
    title = "Declaration of Rights for Cetaceans: Whales and Dolphins",
    year = "2011",
    journal = "Journal of International Wildlife Law \& Policy",
    url = "https://doi.org/10.1080/13880292.2011.557946",
    doi = "10.1080/13880292.2011.557946",
    number = "1",
    openalex = "W4243974015",
    pages = "75-75",
    volume = "14"
}

@article{crossref2011introduction,
    title = "Introduction to the Declaration of Rights for Cetaceans: Whales and Dolphins",
    year = "2011",
    journal = "Journal of International Wildlife Law \& Policy",
    url = "https://doi.org/10.1080/13880292.2011.557948",
    doi = "10.1080/13880292.2011.557948",
    number = "1",
    openalex = "W4252608549",
    pages = "76-77",
    volume = "14"
}

There is currently a great deal of interest in using stable isotope methods to investigate diet, trophic level and migration in wild cetaceans. In order to correctly interpret the results stemming from these methods, it is crucial to understand how diet isotopic values are reflected in consumer tissues. In this study, we investigated patterns of isotopic discrimination between diet and blood constituents of two species of cetaceans (killer whale, Orcinus orca, and bottlenose dolphin, Tursiops truncatus) fed controlled diets over 308 and 312 days, respectively. Diet discrimination factors (Δ; mean ± s.d.) for plasma were estimated to Δ(13)C=2.3±0.6‰ and Δ(15)N=1.8±0.3‰, respectively, for both species and to Δ(13)C=2.7±0.3‰ and Δ(15)N=0.5±0.1‰ for red blood cells. Delipidation did not have a significant effect on carbon and nitrogen isotopic values of blood constituents, confirming that cetacean blood does not serve as a reservoir of lipids. In contrast, carbon isotopic values were higher in delipidated samples of blubber, liver and muscle from killer whales. The potential for conflict between fisheries and cetaceans has heightened the need for trophic information about these taxa. These results provide the first published stable isotope incorporation data for cetaceans, which are essential if conclusions are to be drawn on issues concerning trophic structures, carbon sources and diet reconstruction.

@article{doi101242jeb045104,
    author = "Caut, Stéphane and Laran, Sophie and Garcia-Hartmann, Emmanuel and Das, Krishna",
    title = "Stable isotopes of captive cetaceans (killer whales and bottlenose dolphins)",
    year = "2011",
    journal = "Journal of Experimental Biology",
    abstract = "There is currently a great deal of interest in using stable isotope methods to investigate diet, trophic level and migration in wild cetaceans. In order to correctly interpret the results stemming from these methods, it is crucial to understand how diet isotopic values are reflected in consumer tissues. In this study, we investigated patterns of isotopic discrimination between diet and blood constituents of two species of cetaceans (killer whale, Orcinus orca, and bottlenose dolphin, Tursiops truncatus) fed controlled diets over 308 and 312 days, respectively. Diet discrimination factors (Δ; mean ± s.d.) for plasma were estimated to Δ(13)C=2.3±0.6‰ and Δ(15)N=1.8±0.3‰, respectively, for both species and to Δ(13)C=2.7±0.3‰ and Δ(15)N=0.5±0.1‰ for red blood cells. Delipidation did not have a significant effect on carbon and nitrogen isotopic values of blood constituents, confirming that cetacean blood does not serve as a reservoir of lipids. In contrast, carbon isotopic values were higher in delipidated samples of blubber, liver and muscle from killer whales. The potential for conflict between fisheries and cetaceans has heightened the need for trophic information about these taxa. These results provide the first published stable isotope incorporation data for cetaceans, which are essential if conclusions are to be drawn on issues concerning trophic structures, carbon sources and diet reconstruction.",
    url = "https://doi.org/10.1242/jeb.045104",
    doi = "10.1242/jeb.045104",
    openalex = "W2124793589",
    references = "doi101007s004420031270z, doi101007s004420050865, doi101007s004420060630x, doi1010160307441278900493, doi101016jtree200409004, doi101016s0021925818648495, doi101111j13652664200901620x, doi101111j1469185x200800064x, doi101139z99165, doi1018900012965819970781271siiaea20co2"
}

Behaviour of Indo-Pacific Humpback Dolphin, Sousa chinensis (Osbeck) in the Ashtamudi estuary, southwest coast of India

@article{openalexw574372650,
    author = "Kumar, Appukuttannair Biju and Smrithy, R.",
    title = "Behaviour of Indo-Pacific humpback dolphin, Sousa chinensis (Osbeck) in the Ashtamudi estuary, southwest coast of India",
    year = "2011",
    journal = "Eprints@CMFRI Open Access Institutional Repository (Central Marine Fisheries Research Institute)",
    abstract = "Behaviour of Indo-Pacific Humpback Dolphin, Sousa chinensis (Osbeck) in the Ashtamudi estuary, southwest coast of India",
    openalex = "W574372650",
    references = "doi1047536jcrmv10i3637"
}

RATIONALE: In stable isotope research, the use of accurate, species-specific diet-tissue discrimination factors (i.e., Δ(13)C and Δ(15)N) is central to the estimation of trophic position relative to primary consumers and to the identification of the dietary sources of an individual. Previous research suggested that the diet of fin whales from the waters off northwestern Spain is overwhelmingly based on krill, thus permitting reliable calculation of discrimination values in this wild population. METHODS: After confirming that the stable isotope ratios (δ(13)C and δ(15)N values) in muscle from 65 aged fin whales remained constant through age classes (4-65 years), the signatures were determined in muscle, bone protein, skin, liver, kidney, baleen plates and brain, as well as food (krill), from a subset of individuals to calculate discrimination factors. Signatures were determined by means of elemental analysis isotope ratio mass spectrometry (EA-IRMS) using a ThermoFinnigan Flash 1112. RESULTS: The isotopic values remained constant regardless of age. The mean Δ(15)N values between krill and whale tissues ranged from 2.04 in bone protein to 4.27‰ in brain, and those of Δ(13)C ranged from 1.28 in skin to 3.11‰ in bone protein. This variation was consistent with that found in other groups of mammals, and is attributed to variation in tissue composition and physiology. CONCLUSIONS: Because discrimination factors are relatively constant between taxonomically close species, the results here obtained may be reliably extrapolated to other cetaceans to improve dietary reconstructions. The skin discrimination factors are of particular relevance to monitoring diet through biopsies or other non-destructive sampling methods. The large difference in bone protein discrimination factors from those of other tissues should be taken into consideration when bone collagen is used to determine trophic level or to assess diet in paleodietary isotopic reconstructions.

@article{doi101002rcm6267,
    author = "Borrell, Asunción and Abad‐Oliva, N. and Gómez‐Campos, Encarna and Giménez, Joan and Aguilar, Álex",
    title = "Discrimination of stable isotopes in fin whale tissues and application to diet assessment in cetaceans",
    year = "2012",
    journal = "Rapid Communications in Mass Spectrometry",
    abstract = "RATIONALE: In stable isotope research, the use of accurate, species-specific diet-tissue discrimination factors (i.e., Δ(13)C and Δ(15)N) is central to the estimation of trophic position relative to primary consumers and to the identification of the dietary sources of an individual. Previous research suggested that the diet of fin whales from the waters off northwestern Spain is overwhelmingly based on krill, thus permitting reliable calculation of discrimination values in this wild population. METHODS: After confirming that the stable isotope ratios (δ(13)C and δ(15)N values) in muscle from 65 aged fin whales remained constant through age classes (4-65 years), the signatures were determined in muscle, bone protein, skin, liver, kidney, baleen plates and brain, as well as food (krill), from a subset of individuals to calculate discrimination factors. Signatures were determined by means of elemental analysis isotope ratio mass spectrometry (EA-IRMS) using a ThermoFinnigan Flash 1112. RESULTS: The isotopic values remained constant regardless of age. The mean Δ(15)N values between krill and whale tissues ranged from 2.04 in bone protein to 4.27‰ in brain, and those of Δ(13)C ranged from 1.28 in skin to 3.11‰ in bone protein. This variation was consistent with that found in other groups of mammals, and is attributed to variation in tissue composition and physiology. CONCLUSIONS: Because discrimination factors are relatively constant between taxonomically close species, the results here obtained may be reliably extrapolated to other cetaceans to improve dietary reconstructions. The skin discrimination factors are of particular relevance to monitoring diet through biopsies or other non-destructive sampling methods. The large difference in bone protein discrimination factors from those of other tissues should be taken into consideration when bone collagen is used to determine trophic level or to assess diet in paleodietary isotopic reconstructions.",
    url = "https://doi.org/10.1002/rcm.6267",
    doi = "10.1002/rcm.6267",
    openalex = "W2159250264",
    references = "caut2011stable, doi101007bf00379558, doi101007s004420031270z, doi101007s004420060630x, doi1010160016703778901990, doi1010160016703781902441, doi1010160016703784900917, doi101111j13652664200901620x, doi101139z99165, doi101242jeb045104, doi1018900012965820020830703usitet20co2, doi104319lo20014682061"
}

Post-mortem examination of dead and live stranded beach-cast pinnipeds and cetaceans for determination of a cause of death provides valuable information for the management, mitigation and prosecution of unintentional and sometimes malicious human impacts, such as vessel collision, fishing gear entanglement and gunshot. Delayed discovery, inaccessibility, logistics, human safety concerns, and weather make these events challenging. Over the past 3 decades, in response to public concern and federal and state or provincial regulations mandating such investigations to inform mitigation efforts, there has been an increasing effort to objectively and systematically investigate these strandings from a diagnostic and forensic perspective. This Theme Section provides basic investigative methods, and case definitions for each of the more commonly recognized case presentations of human interactions in pinnipeds and cetaceans. Wild animals are often adversely affected by factors such as parasitism, anthropogenic contaminants, biotoxins, subclinical microbial infections and competing habitat uses, such as prey depletion and elevated background and episodic noise. Understanding the potential contribution of these subclinical factors in predisposing or contributing to a particular case of trauma of human origin is hampered, especially where putrefaction is significant and resources as well as expertise are limited. These case criteria descriptions attempt to acknowledge those confounding factors to enable an appreciation of the significance of the observed human-derived trauma in that broader context where possible.

@article{doi103354dao02566,
    author = "Moore, Michael J. and van der Hoop, Julie and Barco, SG and Costidis, AM and Gulland, FM and Jepson, PD and Moore, K. T. and Raverty, Stephen and McLellan, WA",
    title = "Criteria and case definitions for serious injury and death of pinnipeds and cetaceans caused by anthropogenic trauma",
    year = "2012",
    journal = "Diseases of Aquatic Organisms",
    abstract = "Post-mortem examination of dead and live stranded beach-cast pinnipeds and cetaceans for determination of a cause of death provides valuable information for the management, mitigation and prosecution of unintentional and sometimes malicious human impacts, such as vessel collision, fishing gear entanglement and gunshot. Delayed discovery, inaccessibility, logistics, human safety concerns, and weather make these events challenging. Over the past 3 decades, in response to public concern and federal and state or provincial regulations mandating such investigations to inform mitigation efforts, there has been an increasing effort to objectively and systematically investigate these strandings from a diagnostic and forensic perspective. This Theme Section provides basic investigative methods, and case definitions for each of the more commonly recognized case presentations of human interactions in pinnipeds and cetaceans. Wild animals are often adversely affected by factors such as parasitism, anthropogenic contaminants, biotoxins, subclinical microbial infections and competing habitat uses, such as prey depletion and elevated background and episodic noise. Understanding the potential contribution of these subclinical factors in predisposing or contributing to a particular case of trauma of human origin is hampered, especially where putrefaction is significant and resources as well as expertise are limited. These case criteria descriptions attempt to acknowledge those confounding factors to enable an appreciation of the significance of the observed human-derived trauma in that broader context where possible.",
    url = "https://doi.org/10.3354/dao02566",
    doi = "10.3354/dao02566",
    openalex = "W2051789925",
    references = "doi105597lajam00109"
}

The association of yellowfin tuna and pantropical spotted dolphins in the eastern tropical Pacific Ocean (ETP) has been exploited by tuna fishermen and has intrigued scientists for decades, yet we still have questions about what the benefits of the association are -whether the association is obligatory or facultative, why the tuna are most often found with spotted dolphins, and why the species associate most strongly in the ETP. We review the hypotheses that have been proposed to explain the bond and present results from 3 studies conducted to address these hypotheses: a simultaneous tracking study of spotted dolphins and yellowfin tuna, a trophic interactions study comparing their prey and daily foraging patterns, and a spatial study of oceanographic features correlated with the tuna-dolphin association. These studies demonstrate that the association is neither permanent nor obligatory and that the benefits of the association are not based on feeding advantages. These studies do support the hypothesis that one or both species reduce the risk of predation by forming large, mixed-species groups. The association is most prevalent where the habitat of the tuna is compressed to the warm, shallow, surface waters of the mixed layer by the oxygen minimum zone, a thick layer of oxygen-poor waters underlying the mixed layer. The association has been observed in other oceans with similar oceanographic conditions, but it is most prevalent and consistent in the ETP, where the oxygen minimum zone is the most hypoxic and extensive in the world.

@article{doi103354meps09740,
    author = "Scott, MD and Chivers, S. J. and Olson, RJ and Fiedler, PC and Holland, Kim N.",
    title = "Pelagic predator associations: tuna and dolphins in the eastern tropical Pacific Ocean",
    year = "2012",
    journal = "Marine Ecology Progress Series",
    abstract = "The association of yellowfin tuna and pantropical spotted dolphins in the eastern tropical Pacific Ocean (ETP) has been exploited by tuna fishermen and has intrigued scientists for decades, yet we still have questions about what the benefits of the association are -whether the association is obligatory or facultative, why the tuna are most often found with spotted dolphins, and why the species associate most strongly in the ETP. We review the hypotheses that have been proposed to explain the bond and present results from 3 studies conducted to address these hypotheses: a simultaneous tracking study of spotted dolphins and yellowfin tuna, a trophic interactions study comparing their prey and daily foraging patterns, and a spatial study of oceanographic features correlated with the tuna-dolphin association. These studies demonstrate that the association is neither permanent nor obligatory and that the benefits of the association are not based on feeding advantages. These studies do support the hypothesis that one or both species reduce the risk of predation by forming large, mixed-species groups. The association is most prevalent where the habitat of the tuna is compressed to the warm, shallow, surface waters of the mixed layer by the oxygen minimum zone, a thick layer of oxygen-poor waters underlying the mixed layer. The association has been observed in other oceans with similar oceanographic conditions, but it is most prevalent and consistent in the ETP, where the oxygen minimum zone is the most hypoxic and extensive in the world.",
    url = "https://doi.org/10.3354/meps09740",
    doi = "10.3354/meps09740",
    openalex = "W2097242917",
    references = "doi101111j174876921998tb00736x"
}

The European Union (EU) Habitats Directive requires Member States to monitor and maintain at favourable conservation status those species identified to be in need of protection, including all cetaceans. In July 2005 we surveyed the entire EU Atlantic continental shelf to generate robust estimates of abundance for harbour porpoise and other cetacean species. The survey used line transect sampling methods and purpose built data collection equipment designed to minimise bias in estimates of abundance. Shipboard transects covered 19,725 km in sea conditions ⩽Beaufort 4 in an area of 1,005,743 km2. Aerial transects covered 15,802 km in good/moderate conditions (⩽Beaufort 3) in an area of 364,371 km2. Thirteen cetacean species were recorded; abundance was estimated for harbour porpoise (375,358; CV = 0.197), bottlenose dolphin (16,485; CV = 0.422), white-beaked dolphin (16,536; CV = 0.303), short-beaked common dolphin (56,221; CV = 0.234) and minke whale (18,958; CV = 0.347). Abundance in 2005 was similar to that estimated in July 1994 for harbour porpoise, white-beaked dolphin and minke whale in a comparable area. However, model-based density surfaces showed a marked difference in harbour porpoise distribution between 1994 and 2005. Our results allow EU Member States to discharge their responsibilities under the Habitats Directive and inform other international organisations concerning the assessment of conservation status of cetaceans and the impact of bycatch at a large spatial scale. The lack of evidence for a change in harbour porpoise abundance in EU waters as a whole does not exclude the possibility of an impact of bycatch in some areas. Monitoring bycatch and estimation of abundance continue to be essential.

@article{doi101016jbiocon201304010,
    author = "Hammond, Philip S. and Macleod, Kelly and Berggren, Per and Borchers, David L. and Burt, Louise and Cañadas, Ana and Desportes, Geneviève and Donovan, Greg and Gilles, Anita and Gillespie, Douglas and Gordon, Jonathan and Hiby, Lex and Kuklik, I. and Leaper, Russell and Lehnert, Kristina and Leopold, M.F. and Lovell, Phil and Øien, Nils and Paxton, C. G. M. and Ridoux, Vincent and Rogan, Emer and Samarra, Filipa I. P. and Scheidat, Meike and Sequeira, Marina and Siebert, Ursula and Skov, Henrik and Swift, René and Tasker, Mark L. and Teilmann, Jonas and Canneyt, Olivier Van and Vázquez, José Antonio",
    title = "Cetacean abundance and distribution in European Atlantic shelf waters to inform conservation and management",
    year = "2013",
    journal = "Biological Conservation",
    abstract = "The European Union (EU) Habitats Directive requires Member States to monitor and maintain at favourable conservation status those species identified to be in need of protection, including all cetaceans. In July 2005 we surveyed the entire EU Atlantic continental shelf to generate robust estimates of abundance for harbour porpoise and other cetacean species. The survey used line transect sampling methods and purpose built data collection equipment designed to minimise bias in estimates of abundance. Shipboard transects covered 19,725 km in sea conditions ⩽Beaufort 4 in an area of 1,005,743 km2. Aerial transects covered 15,802 km in good/moderate conditions (⩽Beaufort 3) in an area of 364,371 km2. Thirteen cetacean species were recorded; abundance was estimated for harbour porpoise (375,358; CV = 0.197), bottlenose dolphin (16,485; CV = 0.422), white-beaked dolphin (16,536; CV = 0.303), short-beaked common dolphin (56,221; CV = 0.234) and minke whale (18,958; CV = 0.347). Abundance in 2005 was similar to that estimated in July 1994 for harbour porpoise, white-beaked dolphin and minke whale in a comparable area. However, model-based density surfaces showed a marked difference in harbour porpoise distribution between 1994 and 2005. Our results allow EU Member States to discharge their responsibilities under the Habitats Directive and inform other international organisations concerning the assessment of conservation status of cetaceans and the impact of bycatch at a large spatial scale. The lack of evidence for a change in harbour porpoise abundance in EU waters as a whole does not exclude the possibility of an impact of bycatch in some areas. Monitoring bycatch and estimation of abundance continue to be essential.",
    url = "https://doi.org/10.1016/j.biocon.2013.04.010",
    doi = "10.1016/j.biocon.2013.04.010",
    openalex = "W2005750783",
    references = "doi101111j15231739200600338x"
}

Most current bioexposure assessments for UV filters focus on contaminants concentrations in fish from river and lake. To date there is not information available on the occurrence of UV filters in marine mammals. This is the first study to investigate the presence of sunscreen agents in tissue liver of Franciscana dolphin (Pontoporia blainvillei), a species under special measures for conservation. Fifty six liver tissue samples were taken from dead individuals accidentally caught or found stranded along the Brazilian coastal area (six states). The extensively used octocrylene (2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate, OCT) was frequently found in the samples investigated (21 out of 56) at concentrations in the range 89-782 ng·g(-1) lipid weight. São Paulo was found to be the most polluted area (70% frequency of detection). Nevertheless, the highest concentration was observed in the dolphins from Rio Grande do Sul (42% frequency of detection within that area). These findings constitute the first data reported on the occurrence of UV filters in marine mammals worldwide.

@article{doi101021es400675y,
    author = "Gago-Ferrero, Pablo and Alonso, Mariana B. and Bertozzi, Carolina Pacheco and Marigo, Juliana and Barbosa, Lupércio A. and Cremer, Marta Jussara and Secchi, Eduardo R. and de Freitas Azevedo, Alexandre and Jr., José Lailson-Brito and Torres, João Paulo Machado and Malm, Olaf and Eljarrat, Ethel and Díaz‐Cruz, M. Silvia and Barceló, ‪Damià",
    title = "First Determination of UV Filters in Marine Mammals. Octocrylene Levels in Franciscana Dolphins",
    year = "2013",
    journal = "Environmental Science \& Technology",
    abstract = "Most current bioexposure assessments for UV filters focus on contaminants concentrations in fish from river and lake. To date there is not information available on the occurrence of UV filters in marine mammals. This is the first study to investigate the presence of sunscreen agents in tissue liver of Franciscana dolphin (Pontoporia blainvillei), a species under special measures for conservation. Fifty six liver tissue samples were taken from dead individuals accidentally caught or found stranded along the Brazilian coastal area (six states). The extensively used octocrylene (2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate, OCT) was frequently found in the samples investigated (21 out of 56) at concentrations in the range 89-782 ng·g(-1) lipid weight. São Paulo was found to be the most polluted area (70\% frequency of detection). Nevertheless, the highest concentration was observed in the dolphins from Rio Grande do Sul (42\% frequency of detection within that area). These findings constitute the first data reported on the occurrence of UV filters in marine mammals worldwide.",
    url = "https://doi.org/10.1021/es400675y",
    doi = "10.1021/es400675y",
    openalex = "W2053507910",
    references = "doi101016jchemosphere201009079, doi101016jchemosphere201011018, doi101016jenvpol200911005, doi101016s0025326x02001753, doi101021ac101102d, doi101021es040055r, doi101021es052088s, doi101021es900939j, doi101289ehp10966, doi102305iucnch2003sscap2en"
}

Abstract The global range of R isso's dolphin G rampus griseus is not well known, and there has been confusion in the literature as to whether the species has a broad, circumglobal range or only occurs along continental margins. To clarify the species' distribution and habitat preferences, we compiled and reviewed all available (published and unpublished) records of sightings and captures of this species for the past 62 years (1950–2012, n = 8068 records). Stranding records were not included. The results showed that the species has a range that extends across ocean basins and spans between at least 64°N and 46°S, and is apparently absent from high‐latitude polar waters. Although Risso's dolphins occur in all habitats from coastal to oceanic, they show a strong range‐wide preference for mid‐temperate waters of the continental shelf and slope between 30° and 45° latitude. Although a number of misconceptions about the distributional ecology of Risso's dolphin have existed, this analysis showed that it is a widespread species. It strongly favours temperate waters and prefers continental shelf and slope waters to oceanic depths. These habitat preferences appear to hold throughout much or all of the species' range.

@article{doi101111mam12008,
    author = "Jefferson, Thomas A. and Weir, Caroline R. and Anderson, Robert C. and Ballance, Lisa T. and Kenney, Robert D. and Kiszka, Jérémy J.",
    title = "Global distribution of R isso's dolphin G rampus griseus: a review and critical evaluation",
    year = "2013",
    journal = "Mammal Review",
    abstract = "Abstract The global range of R isso's dolphin G rampus griseus is not well known, and there has been confusion in the literature as to whether the species has a broad, circumglobal range or only occurs along continental margins. To clarify the species' distribution and habitat preferences, we compiled and reviewed all available (published and unpublished) records of sightings and captures of this species for the past 62 years (1950–2012, n = 8068 records). Stranding records were not included. The results showed that the species has a range that extends across ocean basins and spans between at least 64°N and 46°S, and is apparently absent from high‐latitude polar waters. Although Risso's dolphins occur in all habitats from coastal to oceanic, they show a strong range‐wide preference for mid‐temperate waters of the continental shelf and slope between 30° and 45° latitude. Although a number of misconceptions about the distributional ecology of Risso's dolphin have existed, this analysis showed that it is a widespread species. It strongly favours temperate waters and prefers continental shelf and slope waters to oceanic depths. These habitat preferences appear to hold throughout much or all of the species' range.",
    url = "https://doi.org/10.1111/mam.12008",
    doi = "10.1111/mam.12008",
    openalex = "W2143461747",
    references = "doi1047536jcrmv11i1630"
}

Abstract Over‐exploitation of top predators and fish stocks has altered ecosystems towards less productive systems with fewer trophic levels. In the Celtic Sea (CS), discards and bycatch levels have prompted concern about some fisheries, while fin and humpback whales are recovering from centuries of over‐exploitation. A lack of empirical evidence on the preferred diet of some predators such as whales in the CS has hindered the implementation of effective conservation measures using an ecosystem‐based approach to fisheries management. Using a Bayesian framework (SIAR), stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope mixing models were used to assign proportionate diet solutions to fin and humpback whales (skin biopsies) and putative prey items: herring (Clupea harengus), sprat (Sprattus sprattus), and krill (Meganyctiphanes norvegica and Nyctiphanes couchii) in the CS. Krill was the single most important prey item in the diet of fin whales, but one of the least important for humpback whales (albeit based on a small sample of humpback whale samples). Age 0 sprat and herring comprised a large proportion of the diet of both species, followed by older sprat (age 1–2) and older herring (age 2–4). An ecosystem based approach to fisheries management will be required in the CS if we seek effective conservation of both fin and humpback whales, and sustainable fisheries.

@article{doi101111mms12034,
    author = "Ryan, Conor and Berrow, Simon and McHugh, Brendan and O’Donnell, Ciarán and Trueman, Clive N. and O’Connor, Ian",
    title = "Prey preferences of sympatric fin (Balaenoptera physalus) and humpback (Megaptera novaeangliae) whales revealed by stable isotope mixing models",
    year = "2013",
    journal = "Marine Mammal Science",
    abstract = "Abstract Over‐exploitation of top predators and fish stocks has altered ecosystems towards less productive systems with fewer trophic levels. In the Celtic Sea (CS), discards and bycatch levels have prompted concern about some fisheries, while fin and humpback whales are recovering from centuries of over‐exploitation. A lack of empirical evidence on the preferred diet of some predators such as whales in the CS has hindered the implementation of effective conservation measures using an ecosystem‐based approach to fisheries management. Using a Bayesian framework (SIAR), stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope mixing models were used to assign proportionate diet solutions to fin and humpback whales (skin biopsies) and putative prey items: herring (Clupea harengus), sprat (Sprattus sprattus), and krill (Meganyctiphanes norvegica and Nyctiphanes couchii) in the CS. Krill was the single most important prey item in the diet of fin whales, but one of the least important for humpback whales (albeit based on a small sample of humpback whale samples). Age 0 sprat and herring comprised a large proportion of the diet of both species, followed by older sprat (age 1–2) and older herring (age 2–4). An ecosystem based approach to fisheries management will be required in the CS if we seek effective conservation of both fin and humpback whales, and sustainable fisheries.",
    url = "https://doi.org/10.1111/mms.12034",
    doi = "10.1111/mms.12034",
    openalex = "W2137904234",
    references = "caut2011stable, doi101007s0044200312183, doi101007s004420050865, doi1010160016703778901990, doi1010160016703781902441, doi101038nature01017, doi101086409052, doi101126science1098222, doi101126science2795352860, doi101146annureves18110187001453, doi101242jeb045104, doi101371journalpone0009672"
}

Abstract A complementary approach of stomach content and stable isotope analyses was used to characterize the foraging ecology and evaluate niche overlap between pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales stranded on the U.S. mid‐Atlantic coast between 1998 and 2011. Food habits analysis demonstrated both species were primarily teuthophagous, with 35 species of cephalopods, and 2 species of mesopelagic fishes represented in their overall diets. Pianka's Index of niche overlap suggested high overlap between whale diets (O n = 0.92), with squids from the families Histioteuthidae, Cranchidae, and Ommastrephidae serving as primary prey. Pygmy sperm whales consumed slightly larger prey sizes (mean mantle length [ML] = 10.8 cm) than dwarf sperm whales (mean ML = 7.8 cm). Mean prey sizes consumed by pygmy sperm whales increased with growth, but showed no trend in dwarf sperm whales. Significant differences were not detected in δ 15 N and δ 13 C values of muscle tissues from pygmy (10.8‰ ± 0.5‰, −17.1‰ ± 0.6‰), and dwarf sperm whales (10.7‰ ± 0.5‰, −17.0‰ ± 0.4‰), respectively. Isotopic niche widths also did not differ significantly and dietary overlap was high between the two species. Results suggest the feeding ecologies of the pygmy and dwarf sperm whales are similar and both species occupy equivalent trophic niches in the region.

@article{doi101111mms12064,
    author = "Staudinger, Michelle D. and McAlarney, Ryan J. and McLellan, William A. and Pabst, D. Ann",
    title = "Foraging ecology and niche overlap in pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales from waters of the U.S. mid‐Atlantic coast",
    year = "2013",
    journal = "Marine Mammal Science",
    abstract = "Abstract A complementary approach of stomach content and stable isotope analyses was used to characterize the foraging ecology and evaluate niche overlap between pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales stranded on the U.S. mid‐Atlantic coast between 1998 and 2011. Food habits analysis demonstrated both species were primarily teuthophagous, with 35 species of cephalopods, and 2 species of mesopelagic fishes represented in their overall diets. Pianka's Index of niche overlap suggested high overlap between whale diets (O n = 0.92), with squids from the families Histioteuthidae, Cranchidae, and Ommastrephidae serving as primary prey. Pygmy sperm whales consumed slightly larger prey sizes (mean mantle length [ML] = 10.8 cm) than dwarf sperm whales (mean ML = 7.8 cm). Mean prey sizes consumed by pygmy sperm whales increased with growth, but showed no trend in dwarf sperm whales. Significant differences were not detected in δ 15 N and δ 13 C values of muscle tissues from pygmy (10.8‰ ± 0.5‰, −17.1‰ ± 0.6‰), and dwarf sperm whales (10.7‰ ± 0.5‰, −17.0‰ ± 0.4‰), respectively. Isotopic niche widths also did not differ significantly and dietary overlap was high between the two species. Results suggest the feeding ecologies of the pygmy and dwarf sperm whales are similar and both species occupy equivalent trophic niches in the region.",
    url = "https://doi.org/10.1111/mms.12064",
    doi = "10.1111/mms.12064",
    openalex = "W2131948629",
    references = "doi105962p358359"
}

Boat-based surveys were used to investigate the presence of Indo-Pacific Humpback Dolphins Sousa chinensis along the coast of Chennai, Tamil Nadu, India. Notes were collected on behavior, group size, coloration patterns and group composition on sighting cetaceans during the surveys. Four groups of Indo-Pacific Humpback Dolphins were sighted near-shore in the month of February 2011, between 10-25 m depth with an average group size of 20 individuals of which 10 individuals were photo-identifiable. Dominant group behavior was aerial display, feeding and traveling. This study gives a basic idea of presence, threats and habitat use of Humpback Dolphin areas along Chennai coast.

@article{doi1011609jotto345450026,
    author = "Muralidharan, Rahul",
    title = "Sightings and behavioral observations of Indo-Pacific Humpback Dolphins Sousa chinensis (Osbeck, 1765) along Chennai coast, Bay of Bengal",
    year = "2013",
    journal = "Journal of Threatened Taxa",
    abstract = "Boat-based surveys were used to investigate the presence of Indo-Pacific Humpback Dolphins Sousa chinensis along the coast of Chennai, Tamil Nadu, India. Notes were collected on behavior, group size, coloration patterns and group composition on sighting cetaceans during the surveys. Four groups of Indo-Pacific Humpback Dolphins were sighted near-shore in the month of February 2011, between 10-25 m depth with an average group size of 20 individuals of which 10 individuals were photo-identifiable. Dominant group behavior was aerial display, feeding and traveling. This study gives a basic idea of presence, threats and habitat use of Humpback Dolphin areas along Chennai coast.",
    url = "https://doi.org/10.11609/jott.o3454.5002-6",
    doi = "10.11609/jott.o3454.5002-6",
    openalex = "W2325376914",
    references = "doi1047536jcrmv12i2573"
}

Diet-tissue discrimination factors (Δ(15)N or Δ(13)C) and turnover times are thought to be influenced by a wide range of variables including metabolic rate, age, dietary quality, tissue sampled and the taxon being investigated. In the present study, skin samples were collected from ex situ dolphins that had consumed diets of known isotopic composition for a minimum of 8 weeks. Adult dolphins consuming a diet of low fat (5-6%) and high δ(15)N value had significantly lower Δ(15)N values than animals consuming a diet with high fat (13.9%) and low δ(15)N value. Juvenile dolphins consuming a diet with low fat and an intermediate δ(15)N value had significantly higher Δ(15)N values than adults consuming the same diet. Calculated half-lives for δ(15)N ranged from 14 to 23 days (17.2 ± 1.3 days). Half-lives for δ(13)C ranged from 11 to 23 days with a significant difference between low fat (13.9 ± 4.8 days) and high fat diets (22.0 ± 0.5 days). Overall, our results indicate that while assuming a Δ(13)C value of 1‰ may be appropriate for cetaceans, Δ(15)N values may be closer to 1.5‰ rather than the commonly assumed 3‰. Our data also suggest that understanding seasonal variability in prey composition is another significant consideration when applying discrimination factors or turnover times to field studies focused on feeding habits. Isotope retention times of only a few weeks suggest that, in addition, these isotope data could play an important role in interpreting recent fine-scale habitat utilization and residency patterns.

@article{doi101242jeb093963,
    author = "Browning, Nicole and Dold, Christopher and I-Fan, Jack and Worthy, Graham A. J.",
    title = "Isotope turnover rates and diet-tissue discrimination in skin of ex situ Bottlenose Dolphins (Tursiops truncatus)",
    year = "2013",
    journal = "Journal of Experimental Biology",
    abstract = "Diet-tissue discrimination factors (Δ(15)N or Δ(13)C) and turnover times are thought to be influenced by a wide range of variables including metabolic rate, age, dietary quality, tissue sampled and the taxon being investigated. In the present study, skin samples were collected from ex situ dolphins that had consumed diets of known isotopic composition for a minimum of 8 weeks. Adult dolphins consuming a diet of low fat (5-6\%) and high δ(15)N value had significantly lower Δ(15)N values than animals consuming a diet with high fat (13.9\%) and low δ(15)N value. Juvenile dolphins consuming a diet with low fat and an intermediate δ(15)N value had significantly higher Δ(15)N values than adults consuming the same diet. Calculated half-lives for δ(15)N ranged from 14 to 23 days (17.2 ± 1.3 days). Half-lives for δ(13)C ranged from 11 to 23 days with a significant difference between low fat (13.9 ± 4.8 days) and high fat diets (22.0 ± 0.5 days). Overall, our results indicate that while assuming a Δ(13)C value of 1‰ may be appropriate for cetaceans, Δ(15)N values may be closer to 1.5‰ rather than the commonly assumed 3‰. Our data also suggest that understanding seasonal variability in prey composition is another significant consideration when applying discrimination factors or turnover times to field studies focused on feeding habits. Isotope retention times of only a few weeks suggest that, in addition, these isotope data could play an important role in interpreting recent fine-scale habitat utilization and residency patterns.",
    url = "https://doi.org/10.1242/jeb.093963",
    doi = "10.1242/jeb.093963",
    openalex = "W2145575644",
    references = "doi101002rcm6267"
}

Collisions with vessels are a serious threat to a number of endangered large whale species, the North Atlantic right whale (Eubalaena glacialis) in particular. In late 2008, the U.S. National Oceanic and Atmospheric Administration issued mandatory time‐area vessel speed restrictions along the U.S. eastern seaboard in an effort to mediate collision‐related mortality of right whales. All vessels 65 feet and greater in length are restricted to speeds of 10 knots or less during seasonally implemented regulatory periods. We modeled mortality risk of North Atlantic right whale when the vessel restrictions were and were not in effect, including (1) estimation of the probability of lethal injury given a ship strike as a function of vessel speed, (2) estimation of the effect of transit speed on the instantaneous rate of ship strikes, and (3) a consideration of total risk reduction. Logistic regression and Bayesian probit analyses indicated a significant positive relationship between ship speed and the probability of a lethal injury. We found that speeds of vessels that struck whales were consistently greater than typical vessel speeds for each vessel type and regulatory period studied; a use‐availability model fit to these data provided strong evidence for a linear effect of transit speed on strike rates. Overall, we estimated that vessel speed restrictions reduced total ship strike mortality risk levels by 80–90% with levels that were closer to 90% in the latter two of the four active vessel speed restriction periods studied. To our knowledge, this is the most comprehensive assessment to date of the utility of vessel speed restrictions in reducing the threat of vessel collisions to large whales. Our findings indicate that vessel speed limits are a powerful tool for reducing anthropogenic mortality risk for North Atlantic right whales.

@article{doi101890es13000041,
    author = "Conn, Paul B. and Silber, G. K.",
    title = "Vessel speed restrictions reduce risk of collision‐related mortality for North Atlantic right whales",
    year = "2013",
    journal = "Ecosphere",
    abstract = "Collisions with vessels are a serious threat to a number of endangered large whale species, the North Atlantic right whale (Eubalaena glacialis) in particular. In late 2008, the U.S. National Oceanic and Atmospheric Administration issued mandatory time‐area vessel speed restrictions along the U.S. eastern seaboard in an effort to mediate collision‐related mortality of right whales. All vessels 65 feet and greater in length are restricted to speeds of 10 knots or less during seasonally implemented regulatory periods. We modeled mortality risk of North Atlantic right whale when the vessel restrictions were and were not in effect, including (1) estimation of the probability of lethal injury given a ship strike as a function of vessel speed, (2) estimation of the effect of transit speed on the instantaneous rate of ship strikes, and (3) a consideration of total risk reduction. Logistic regression and Bayesian probit analyses indicated a significant positive relationship between ship speed and the probability of a lethal injury. We found that speeds of vessels that struck whales were consistently greater than typical vessel speeds for each vessel type and regulatory period studied; a use‐availability model fit to these data provided strong evidence for a linear effect of transit speed on strike rates. Overall, we estimated that vessel speed restrictions reduced total ship strike mortality risk levels by 80–90\% with levels that were closer to 90\% in the latter two of the four active vessel speed restriction periods studied. To our knowledge, this is the most comprehensive assessment to date of the utility of vessel speed restrictions in reducing the threat of vessel collisions to large whales. Our findings indicate that vessel speed limits are a powerful tool for reducing anthropogenic mortality risk for North Atlantic right whales.",
    url = "https://doi.org/10.1890/es13-00004.1",
    doi = "10.1890/es13-00004.1",
    openalex = "W2096362578",
    references = "doi105597lajam00109"
}

Biological and fisheries data were analysed to assess the impact of fisheries mortality on a Critically Endangered subpopulation of 30% of the ETS Sousa subpopulation exhibited injuries caused by fishing gear. Three individuals were photographed with fishing gear attached to their bodies, and 1 dolphin was found dead with fresh injuries caused by fishing gear. To ensure recovery of ETS Sousa, mortality due to human causes should be reduced to <1 individual every 7 yr. Fisheries bycatch is the most serious threat to these dolphins and needs to be eliminated as soon as possible to avoid extinction. Preventing the use of trammel nets, other gillnets and trawling throughout their habitat would be the single most effective conservation measure for ETS Sousa in the short term. Other fishing methods are available, and using the most selective, sustainable fishing methods available will benefit not only dolphins but also fish stocks, seabirds and other species, as well as the fishing industry, which depends on these species for its long-term viability. However, in the short term, there are costs associated with switching to more selective fishing gear.

@article{doi103354esr00518,
    author = "Slooten, Elisabeth and Wang, JY and Dungan, Sarah Z. and Forney, KA and Hung, Shih‐Kai and Jefferson, TA and Riehl, KN and Rojas‐Bracho, Lorenzo and Ross, PS and Wee, Alison K. S. and Winkler, Robin C. and Yang, SC and Chen, Chi‐An",
    title = "Impacts of fisheries on the Critically Endangered humpback dolphin Sousa chinensis population in the eastern Taiwan Strait",
    year = "2013",
    journal = "Endangered Species Research",
    abstract = "Biological and fisheries data were analysed to assess the impact of fisheries mortality on a Critically Endangered subpopulation of 30\% of the ETS Sousa subpopulation exhibited injuries caused by fishing gear. Three individuals were photographed with fishing gear attached to their bodies, and 1 dolphin was found dead with fresh injuries caused by fishing gear. To ensure recovery of ETS Sousa, mortality due to human causes should be reduced to <1 individual every 7 yr. Fisheries bycatch is the most serious threat to these dolphins and needs to be eliminated as soon as possible to avoid extinction. Preventing the use of trammel nets, other gillnets and trawling throughout their habitat would be the single most effective conservation measure for ETS Sousa in the short term. Other fishing methods are available, and using the most selective, sustainable fishing methods available will benefit not only dolphins but also fish stocks, seabirds and other species, as well as the fishing industry, which depends on these species for its long-term viability. However, in the short term, there are costs associated with switching to more selective fishing gear.",
    url = "https://doi.org/10.3354/esr00518",
    doi = "10.3354/esr00518",
    openalex = "W2069371706",
    references = "doi101578am3012004111"
}

Abstract This paper provides a synthesis of results obtained as part of a long-term collaborative study involving biologists, fishers, and resource managers—centring on the occurrence of killer whales in the Crozet Archipelago before and after the implementation of a demersal longline fishery for Patagonian toothfish. Depredation behaviour was reported as soon as the fishery was initiated, with dramatic effects on both the demographic trajectories of the killer whales and on the amount of fish lost by the fishers. Killer whales interacting with the fishery exhibited very high mortality rates when illegal fishing took place, while killer whales not interacting were unaffected. However, after illegal fishing ended, killer whales interacting with the fishery exhibited both higher fecundity and survival rates compared with killer whales not interacting. Since whales typically removed fish entirely from the hooks, an adapted methodology that did not rely on determining the number of damaged fish was developed to estimate depredation rates. In the Crozet EEZ over a 10-year period, 33.9% of the total amount of Patagonian toothfish caught, representing a total of 28 million €, was estimated to be lost due to the combined effects of killer whale and sperm whale depredation. In an effort to reduce depredation losses, modifications to fishing methods, such as changing the fishing season, changing fishing areas when exposed to depredation and changing longline length and hauling speed were successfully tested. Acoustic deterrent devices were ineffective in deterring killer whales from depredating longlines. Alternative fishing gears, such as fish pots, were also tested. However, while providing encouraging results regarding the suppression of depredation and seabird bycatch, fish pots were not efficient enough to sustain an economically viable fishery. In conclusion, we discuss how the findings of this comprehensive study can be used elsewhere in fisheries confronted with depredation.

@article{doi101093icesjmsfsu221,
    author = "Guinet, Christophe and Tixier, Paul and Gasco, Nicolas and Duhamel, Guy",
    title = "Long-term studies of Crozet Island killer whales are fundamental to understanding the economic and demographic consequences of their depredation behaviour on the Patagonian toothfish fishery",
    year = "2014",
    journal = "ICES Journal of Marine Science",
    abstract = "Abstract This paper provides a synthesis of results obtained as part of a long-term collaborative study involving biologists, fishers, and resource managers—centring on the occurrence of killer whales in the Crozet Archipelago before and after the implementation of a demersal longline fishery for Patagonian toothfish. Depredation behaviour was reported as soon as the fishery was initiated, with dramatic effects on both the demographic trajectories of the killer whales and on the amount of fish lost by the fishers. Killer whales interacting with the fishery exhibited very high mortality rates when illegal fishing took place, while killer whales not interacting were unaffected. However, after illegal fishing ended, killer whales interacting with the fishery exhibited both higher fecundity and survival rates compared with killer whales not interacting. Since whales typically removed fish entirely from the hooks, an adapted methodology that did not rely on determining the number of damaged fish was developed to estimate depredation rates. In the Crozet EEZ over a 10-year period, 33.9\% of the total amount of Patagonian toothfish caught, representing a total of 28 million €, was estimated to be lost due to the combined effects of killer whale and sperm whale depredation. In an effort to reduce depredation losses, modifications to fishing methods, such as changing the fishing season, changing fishing areas when exposed to depredation and changing longline length and hauling speed were successfully tested. Acoustic deterrent devices were ineffective in deterring killer whales from depredating longlines. Alternative fishing gears, such as fish pots, were also tested. However, while providing encouraging results regarding the suppression of depredation and seabird bycatch, fish pots were not efficient enough to sustain an economically viable fishery. In conclusion, we discuss how the findings of this comprehensive study can be used elsewhere in fisheries confronted with depredation.",
    url = "https://doi.org/10.1093/icesjms/fsu221",
    doi = "10.1093/icesjms/fsu221",
    openalex = "W2155635901",
    references = "doi1010160967065396842815"
}

Abstract The taxonomy of the humpback dolphin genus Sousa has been controversial and unsettled for centuries, but recent work indicates that there are several valid species. A review of multiple lines of evidence from skeletal morphology, external morphology, coloration, molecular genetics, and biogeography, in combination provides strong support for the recognition of four species of Sousa. These include S. teuszii (Kükenthal, 1892), a species with uniform gray coloration and a prominent dorsal hump, which is found in the Atlantic Ocean off West Africa. The species S. plumbea (G. Cuvier, 1829) has similar external appearance to S. teuszii, but has a more pointed dorsal fin. It occurs in the Indian Ocean from South Africa to Myanmar (Burma). The original taxon, S. chinensis (Osbeck, 1765), is reserved for the species that has a larger dorsal fin with no prominent hump, and largely white adult coloration. It ranges from eastern India to central China and throughout Southeast Asia. Finally, we describe a new species of Sousa, the Australian humpback dolphin, which occurs in the waters of the Sahul Shelf from northern Australia to southern New Guinea. It has a lower dorsal fin, more extensive dark color on the body, and a dorsal “cape.” It is separated from the Indo‐Pacific humpback dolphin by a wide distributional gap that coincides with Wallace's Line.

@article{doi101111mms12152,
    author = "Jefferson, Thomas A. and Rosenbaum, Howard C.",
    title = "Taxonomic revision of the humpback dolphins (Sousa spp.), and description of a new species from Australia",
    year = "2014",
    journal = "Marine Mammal Science",
    abstract = "Abstract The taxonomy of the humpback dolphin genus Sousa has been controversial and unsettled for centuries, but recent work indicates that there are several valid species. A review of multiple lines of evidence from skeletal morphology, external morphology, coloration, molecular genetics, and biogeography, in combination provides strong support for the recognition of four species of Sousa. These include S. teuszii (Kükenthal, 1892), a species with uniform gray coloration and a prominent dorsal hump, which is found in the Atlantic Ocean off West Africa. The species S. plumbea (G. Cuvier, 1829) has similar external appearance to S. teuszii, but has a more pointed dorsal fin. It occurs in the Indian Ocean from South Africa to Myanmar (Burma). The original taxon, S. chinensis (Osbeck, 1765), is reserved for the species that has a larger dorsal fin with no prominent hump, and largely white adult coloration. It ranges from eastern India to central China and throughout Southeast Asia. Finally, we describe a new species of Sousa, the Australian humpback dolphin, which occurs in the waters of the Sahul Shelf from northern Australia to southern New Guinea. It has a lower dorsal fin, more extensive dark color on the body, and a dorsal “cape.” It is separated from the Indo‐Pacific humpback dolphin by a wide distributional gap that coincides with Wallace's Line.",
    url = "https://doi.org/10.1111/mms.12152",
    doi = "10.1111/mms.12152",
    openalex = "W1967251255",
    references = "doi101578am3012004125, doi1016441545141020016550001sc20co2"
}

We report the presence and behaviour of a pod of short-finned pilot whale Globicephala macrorhynchus in the southeastern Arabian Sea. The pod was observed in the southeastern side of Minicoy Island, in the Nine degree channel (09°219′23′′N;74°39′529′′E) on 03.02.2013. Later, on 06.02.2013,the same pod of pilot whales were observed near Kalpeni Island (10°02′402′′N; 73°39′579′′E) 130 km northwest of the previous location. The average length of the whales was estimated as 550 cm and weight as approximately 1200 kg. They were travelling in a northwesterly direction. The pod size of the whales sighted was twelve and several species specific behaviour such as side rolling, spyhopping, lobtailing, peduncle arching and movement patterns such as synchronous travelling and logging could be observed. The occurrence of scars and injuries on the body of four whales in the pod are also reported.

@article{doi1011609jotto3659648892,
    author = "Sajikumar, Kurichithara K. and Ragesh, N and Mohamed, K S",
    title = "Behaviour of Short-finned Pilot Whales Globicephala macrorhynchus (Gray, 1846) (Mammalia: Cetartiodactyla: Delphinidae) in the southeastern Arabian Sea",
    year = "2014",
    journal = "Journal of Threatened Taxa",
    abstract = "We report the presence and behaviour of a pod of short-finned pilot whale Globicephala macrorhynchus in the southeastern Arabian Sea. The pod was observed in the southeastern side of Minicoy Island, in the Nine degree channel (09°219′23′′N;74°39′529′′E) on 03.02.2013. Later, on 06.02.2013,the same pod of pilot whales were observed near Kalpeni Island (10°02′402′′N; 73°39′579′′E) 130 km northwest of the previous location. The average length of the whales was estimated as 550 cm and weight as approximately 1200 kg. They were travelling in a northwesterly direction. The pod size of the whales sighted was twelve and several species specific behaviour such as side rolling, spyhopping, lobtailing, peduncle arching and movement patterns such as synchronous travelling and logging could be observed. The occurrence of scars and injuries on the body of four whales in the pod are also reported.",
    url = "https://doi.org/10.11609/jott.o3659.6488-92",
    doi = "10.11609/jott.o3659.6488-92",
    openalex = "W2016472969",
    references = "doi1047536jcrmv12i2573"
}

To date, most habitat models of cetaceans have relied on static and oceanographic covariates, and very few have related cetaceans directly to the distribution of their prey, as a result of the limited availability of prey data. By simulating the distribution of six functional micronekton groups between the surface and ≃1,000 m deep, the SEAPODYM model provides valuable insights into prey distributions. We used SEAPODYM outputs to investigate the habitat of three cetacean guilds with increasing energy requirements: sperm and beaked whales, Globicephalinae and Delphininae. We expected High Energy Requirements cetaceans to preferentially forage in habitats of high prey biomass and/or production, where they might easily meet their high energetic needs, and Low Energy Requirements cetaceans to forage in habitats of either high or low prey biomass and/or production. Cetacean sightings were collected from dedicated aerial surveys in the South West Indian Ocean (SWIO) and French Polynesia (FP). We examined cetacean densities in relation to simulated distributions of their potential prey using Generalised Additive Models and predicted their habitats in both regions. Results supported their known diving abilities, with Delphininae mostly related to prey present in the upper layers of the water column, and Globicephalinae and sperm and beaked whales also related to prey present in deeper layers. Explained deviances ranged from 9% for sperm and beaked whales in the SWIO to 47% for Globicephalinae in FP. Delphininae and Globicephalinae appeared to select areas where high prey biomass and/or production were available at shallow depths. In contrast, sperm and beaked whales showed less clear habitat selection. Using simulated prey distributions as predictors in cetacean habitat models is crucial to understand their strategies of habitat selection in the three dimensions of the ocean.

@article{doi101371journalpone0105958,
    author = "Lambert, Charlotte and Mannocci, Laura and Lehodey, Patrick and Ridoux, Vincent",
    title = "Predicting Cetacean Habitats from Their Energetic Needs and the Distribution of Their Prey in Two Contrasted Tropical Regions",
    year = "2014",
    journal = "PLoS ONE",
    abstract = "To date, most habitat models of cetaceans have relied on static and oceanographic covariates, and very few have related cetaceans directly to the distribution of their prey, as a result of the limited availability of prey data. By simulating the distribution of six functional micronekton groups between the surface and ≃1,000 m deep, the SEAPODYM model provides valuable insights into prey distributions. We used SEAPODYM outputs to investigate the habitat of three cetacean guilds with increasing energy requirements: sperm and beaked whales, Globicephalinae and Delphininae. We expected High Energy Requirements cetaceans to preferentially forage in habitats of high prey biomass and/or production, where they might easily meet their high energetic needs, and Low Energy Requirements cetaceans to forage in habitats of either high or low prey biomass and/or production. Cetacean sightings were collected from dedicated aerial surveys in the South West Indian Ocean (SWIO) and French Polynesia (FP). We examined cetacean densities in relation to simulated distributions of their potential prey using Generalised Additive Models and predicted their habitats in both regions. Results supported their known diving abilities, with Delphininae mostly related to prey present in the upper layers of the water column, and Globicephalinae and sperm and beaked whales also related to prey present in deeper layers. Explained deviances ranged from 9\% for sperm and beaked whales in the SWIO to 47\% for Globicephalinae in FP. Delphininae and Globicephalinae appeared to select areas where high prey biomass and/or production were available at shallow depths. In contrast, sperm and beaked whales showed less clear habitat selection. Using simulated prey distributions as predictors in cetacean habitat models is crucial to understand their strategies of habitat selection in the three dimensions of the ocean.",
    url = "https://doi.org/10.1371/journal.pone.0105958",
    doi = "10.1371/journal.pone.0105958",
    openalex = "W2044901417",
    references = "doi105962p358359"
}

Baleen and sperm whales, known collectively as the great whales, include the largest animals in the history of life on Earth. With high metabolic demands and large populations, whales probably had a strong influence on marine ecosystems before the advent of industrial whaling: as consumers of fish and invertebrates; as prey to other large‐bodied predators; as reservoirs of and vertical and horizontal vectors for nutrients; and as detrital sources of energy and habitat in the deep sea. The decline in great whale numbers, estimated to be at least 66% and perhaps as high as 90%, has likely altered the structure and function of the oceans, but recovery is possible and in many cases is already underway. Future changes in the structure and function of the world's oceans can be expected with the restoration of great whale populations.

@article{doi101890130220,
    author = "Roman, Joe and Estes, James A. and Morissette, Lyne and Smith, Craig R. and Costa, Daniel P. and McCarthy, James J. and Nation, J. B. and Nicol, Stephen and Pershing, Andrew J. and Smetacek, Victor",
    title = "Whales as marine ecosystem engineers",
    year = "2014",
    journal = "Frontiers in Ecology and the Environment",
    abstract = "Baleen and sperm whales, known collectively as the great whales, include the largest animals in the history of life on Earth. With high metabolic demands and large populations, whales probably had a strong influence on marine ecosystems before the advent of industrial whaling: as consumers of fish and invertebrates; as prey to other large‐bodied predators; as reservoirs of and vertical and horizontal vectors for nutrients; and as detrital sources of energy and habitat in the deep sea. The decline in great whale numbers, estimated to be at least 66\% and perhaps as high as 90\%, has likely altered the structure and function of the oceans, but recovery is possible and in many cases is already underway. Future changes in the structure and function of the world's oceans can be expected with the restoration of great whale populations.",
    url = "https://doi.org/10.1890/130220",
    doi = "10.1890/130220",
    openalex = "W2161323358",
    references = "doi101186147121487127"
}

@misc{dold2014cetaceans,
    author = "Dold, Christopher and Ridgway, Sam",
    title = "Cetaceans",
    year = "2014",
    booktitle = "Zoo Animal and Wildlife Immobilization and Anesthesia",
    url = "https://doi.org/10.1002/9781118792919.ch49",
    doi = "10.1002/9781118792919.ch49",
    pages = "679-691"
}

Chinese white dolphins (Sousa chinensis) inhabiting shallow coastal waters are vulnerable to impacts from human activities in the near shore waters. This study examined the population of Chinese white dolphins occurring off the coast of Zhanjiang in the northern South China Sea. A total of 492 Chinese white dolphins were identified, 176 of which were photographed on more than one occasion. The Zhanjiang Chinese white dolphin population is isolated from populations of conspecifics along the Guangdong coast. It is composed of approximately 1485 individuals (95% CI = 1371-1629; SE = 63.8), with estimates of mean representative range and core area of 168.51 and 44.26 km(2), respectively. The high site fidelity and long-term residence of Chinese white dolphins in the study area are well established. A review of all available data indicates that based on what is currently known, the Zhanjiang Chinese white dolphin population is the second largest of the species and genus in the world. However, the recent industrial boom along the Zhanjiang coast has increased concerns regarding the conservation of the Zhanjiang Chinese white dolphin population. We recommend the designation of a national nature reserve as a most urgent measure for protecting Chinese white dolphins in Zhanjiang waters.

@article{doi101038srep08147,
    author = "Xu, Xinrong and Song, Jinyuan and Zhang, Zhenhua and Li, Peng and Yang, Guang and Zhou, Kaiya",
    title = "The world's second largest population of humpback dolphins in the waters of Zhanjiang deserves the highest conservation priority",
    year = "2015",
    journal = "Scientific Reports",
    abstract = "Chinese white dolphins (Sousa chinensis) inhabiting shallow coastal waters are vulnerable to impacts from human activities in the near shore waters. This study examined the population of Chinese white dolphins occurring off the coast of Zhanjiang in the northern South China Sea. A total of 492 Chinese white dolphins were identified, 176 of which were photographed on more than one occasion. The Zhanjiang Chinese white dolphin population is isolated from populations of conspecifics along the Guangdong coast. It is composed of approximately 1485 individuals (95\% CI = 1371-1629; SE = 63.8), with estimates of mean representative range and core area of 168.51 and 44.26 km(2), respectively. The high site fidelity and long-term residence of Chinese white dolphins in the study area are well established. A review of all available data indicates that based on what is currently known, the Zhanjiang Chinese white dolphin population is the second largest of the species and genus in the world. However, the recent industrial boom along the Zhanjiang coast has increased concerns regarding the conservation of the Zhanjiang Chinese white dolphin population. We recommend the designation of a national nature reserve as a most urgent measure for protecting Chinese white dolphins in Zhanjiang waters.",
    url = "https://doi.org/10.1038/srep08147",
    doi = "10.1038/srep08147",
    openalex = "W1998012003",
    references = "doi101578am3012004125"
}

The Omura's whale (Balaenoptera omurai) was described as a new species in 2003 and then soon after as an ancient lineage basal to a Bryde's/sei whale clade. Currently known only from whaling and stranding specimens primarily from the western Pacific and eastern Indian Oceans, there exist no confirmed field observations or ecological/behavioural data. Here we present, to our knowledge, the first genetically confirmed documentation of living Omura's whales including descriptions of basic ecology and behaviour from northwestern Madagascar. Species identification was confirmed through molecular phylogenetic analyses of biopsies collected from 18 adult animals. All individuals shared a single haplotype in a 402 bp sequence of mtDNA control region, suggesting low diversity and a potentially small population. Sightings of 44 groups indicated preference for shallow-water shelf habitat with sea surface temperature between 27.4°C and 30.2°C. Frequent observations were made of lunge feeding, possibly on zooplankton. Observations of four mothers with young calves, and recordings of a song-like vocalization probably indicate reproductive behaviour. Social organization consisted of loose aggregations of predominantly unassociated single individuals spatially and temporally clustered. Photographic recapture of a female re-sighted the following year with a young calf suggests site fidelity or a resident population. Our results demonstrate that the species is a tropical whale without segregation of feeding and breeding habitat, and is probably non-migratory; our data extend the range of this poorly studied whale into the western Indian Ocean. Exclusive range restriction to tropical waters is rare among baleen whale species, except for the various forms of Bryde's whales and Omura's whales. Thus, the discovery of a tractable population of Omura's whales in the tropics presents an opportunity for understanding the ecological factors driving potential convergence of life-history patterns with the distantly related Bryde's whales.

@article{doi101098rsos150301,
    author = "Cerchio, Salvatore and Andrianantenaina, Boris and Lindsay, Alec R. and Rekdahl, Melinda L. and Andrianarivelo, Norbert and Rasoloarijao, Tahina",
    title = "Omura’s whales (Balaenoptera omurai) off northwest Madagascar: ecology, behaviour and conservation needs",
    year = "2015",
    journal = "Royal Society Open Science",
    abstract = "The Omura's whale (Balaenoptera omurai) was described as a new species in 2003 and then soon after as an ancient lineage basal to a Bryde's/sei whale clade. Currently known only from whaling and stranding specimens primarily from the western Pacific and eastern Indian Oceans, there exist no confirmed field observations or ecological/behavioural data. Here we present, to our knowledge, the first genetically confirmed documentation of living Omura's whales including descriptions of basic ecology and behaviour from northwestern Madagascar. Species identification was confirmed through molecular phylogenetic analyses of biopsies collected from 18 adult animals. All individuals shared a single haplotype in a 402 bp sequence of mtDNA control region, suggesting low diversity and a potentially small population. Sightings of 44 groups indicated preference for shallow-water shelf habitat with sea surface temperature between 27.4°C and 30.2°C. Frequent observations were made of lunge feeding, possibly on zooplankton. Observations of four mothers with young calves, and recordings of a song-like vocalization probably indicate reproductive behaviour. Social organization consisted of loose aggregations of predominantly unassociated single individuals spatially and temporally clustered. Photographic recapture of a female re-sighted the following year with a young calf suggests site fidelity or a resident population. Our results demonstrate that the species is a tropical whale without segregation of feeding and breeding habitat, and is probably non-migratory; our data extend the range of this poorly studied whale into the western Indian Ocean. Exclusive range restriction to tropical waters is rare among baleen whale species, except for the various forms of Bryde's whales and Omura's whales. Thus, the discovery of a tractable population of Omura's whales in the tropics presents an opportunity for understanding the ecological factors driving potential convergence of life-history patterns with the distantly related Bryde's whales.",
    url = "https://doi.org/10.1098/rsos.150301",
    doi = "10.1098/rsos.150301",
    openalex = "W1912679604",
    references = "doi101111j174876921999tb00890x"
}

Abstract The global distribution of fin whales B alaenoptera physalus is not fully understood. Existing maps can be divided into two conflicting categories: one showing a continuous global distribution and another showing an equatorial hiatus (gap in the global distribution) between approximately 20° N and 20° S. Questions also remain about the seasonal distribution of fin whales. To explore the suggested equatorial hiatus and seasonal distribution patterns, we synthesised information on fin whale distribution in the post‐whaling era (1980–2012) from published literature, publicly available reports and studies conducted by various organisations. We created four seasonally stratified maps showing line‐transect density estimates, line‐transect survey effort, acoustic detections, and sightings. An equatorial hiatus in the global distribution of fin whales during the post‐whaling era is supported by numerous line‐transect surveys and by the rarity of equatorial acoustic detections and sightings, and corroborated by whaling era reports, morphological analyses, and genetic analyses. Our synthesis of post‐whaling era data is consistent with results from other studies indicating that fin whales are more abundant at higher latitudes during warmer months and more abundant at lower latitudes (although these latitudes are still greater than 20°) during colder months. However, our synthesis and results from other studies also indicate that some fin whales in both hemispheres remain in higher latitudes (50°–60° north or south) during colder months and in lower latitudes (to approximately 20°–30° north or south) during warmer months, indicating that seasonal fin whale movements differ from the seasonal migrations of blue whales B alaenoptera musculus and humpback whales M egaptera novaeangliae. Our maps of global fin whale distribution provide a comprehensive picture of current knowledge and highlight important geographical and temporal data gaps. Surveys should be conducted within the identified data gaps in order to increase fine‐scale spatial and temporal knowledge of distribution patterns, improve fin whale taxonomy, and identify areas of elevated fin whale densities that may require management of threats, such as ship strikes.

@article{doi101111mam12048,
    author = "Edwards, Elizabeth F. and Hall, Candice and Moore, Thomas J. and Sheredy, Corey and Redfern, Jessica V.",
    title = "Global distribution of fin whales B alaenoptera physalus in the post‐whaling era (1980–2012)",
    year = "2015",
    journal = "Mammal Review",
    abstract = "Abstract The global distribution of fin whales B alaenoptera physalus is not fully understood. Existing maps can be divided into two conflicting categories: one showing a continuous global distribution and another showing an equatorial hiatus (gap in the global distribution) between approximately 20° N and 20° S. Questions also remain about the seasonal distribution of fin whales. To explore the suggested equatorial hiatus and seasonal distribution patterns, we synthesised information on fin whale distribution in the post‐whaling era (1980–2012) from published literature, publicly available reports and studies conducted by various organisations. We created four seasonally stratified maps showing line‐transect density estimates, line‐transect survey effort, acoustic detections, and sightings. An equatorial hiatus in the global distribution of fin whales during the post‐whaling era is supported by numerous line‐transect surveys and by the rarity of equatorial acoustic detections and sightings, and corroborated by whaling era reports, morphological analyses, and genetic analyses. Our synthesis of post‐whaling era data is consistent with results from other studies indicating that fin whales are more abundant at higher latitudes during warmer months and more abundant at lower latitudes (although these latitudes are still greater than 20°) during colder months. However, our synthesis and results from other studies also indicate that some fin whales in both hemispheres remain in higher latitudes (50°–60° north or south) during colder months and in lower latitudes (to approximately 20°–30° north or south) during warmer months, indicating that seasonal fin whale movements differ from the seasonal migrations of blue whales B alaenoptera musculus and humpback whales M egaptera novaeangliae. Our maps of global fin whale distribution provide a comprehensive picture of current knowledge and highlight important geographical and temporal data gaps. Surveys should be conducted within the identified data gaps in order to increase fine‐scale spatial and temporal knowledge of distribution patterns, improve fin whale taxonomy, and identify areas of elevated fin whale densities that may require management of threats, such as ship strikes.",
    url = "https://doi.org/10.1111/mam.12048",
    doi = "10.1111/mam.12048",
    openalex = "W1894456216",
    references = "doi101111j174876921998tb00736x"
}

Abstract No global synthesis of the status of baleen whales has been published since the 2008 IUCN Red List assessments. Many populations remain at low numbers from historical commercial whaling, which had ceased for all but a few by 1989. Fishing gear entanglement and ship strikes are the most severe current threats. The acute and long‐term effects of anthropogenic noise and the cumulative effects of multiple stressors are of concern but poorly understood. The looming consequences of climate change and ocean acidification remain difficult to characterize. North Atlantic and North Pacific right whales are among the species listed as Endangered. Southern right, bowhead, and gray whales have been assessed as Least Concern but some subpopulations of these species ‐ western North Pacific gray whales, Chile‐Peru right whales, and Svalbard/Barents Sea and Sea of Okhotsk bowhead whales ‐ remain at low levels and are either Endangered or Critically Endangered. Eastern North Pacific blue whales have reportedly recovered, but Antarctic blue whales remain at about 1% of pre‐exploitation levels. Small isolated subspecies or subpopulations, such as northern Indian Ocean blue whales, Arabian Sea humpback whales, and Mediterranean Sea fin whales are threatened while most subpopulations of sei, Bryde's, and Omura's whales are inadequately monitored and difficult to assess.

@article{doi101111mms12281,
    author = "Thomas, Peter O. and Reeves, Randall R. and Brownell, Robert L.",
    title = "Status of the world's baleen whales",
    year = "2015",
    journal = "Marine Mammal Science",
    abstract = "Abstract No global synthesis of the status of baleen whales has been published since the 2008 IUCN Red List assessments. Many populations remain at low numbers from historical commercial whaling, which had ceased for all but a few by 1989. Fishing gear entanglement and ship strikes are the most severe current threats. The acute and long‐term effects of anthropogenic noise and the cumulative effects of multiple stressors are of concern but poorly understood. The looming consequences of climate change and ocean acidification remain difficult to characterize. North Atlantic and North Pacific right whales are among the species listed as Endangered. Southern right, bowhead, and gray whales have been assessed as Least Concern but some subpopulations of these species ‐ western North Pacific gray whales, Chile‐Peru right whales, and Svalbard/Barents Sea and Sea of Okhotsk bowhead whales ‐ remain at low levels and are either Endangered or Critically Endangered. Eastern North Pacific blue whales have reportedly recovered, but Antarctic blue whales remain at about 1\% of pre‐exploitation levels. Small isolated subspecies or subpopulations, such as northern Indian Ocean blue whales, Arabian Sea humpback whales, and Mediterranean Sea fin whales are threatened while most subpopulations of sei, Bryde's, and Omura's whales are inadequately monitored and difficult to assess.",
    url = "https://doi.org/10.1111/mms.12281",
    doi = "10.1111/mms.12281",
    openalex = "W2181364932",
    references = "doi101038367108a0, doi101111j13652907200700106x, doi103354esr00197"
}

Kogiids are known by two living species, the pygmy and dwarf sperm whale (Kogia breviceps and K. sima). Both are relatively rare, and as their names suggest, they are closely related to the sperm whale, all being characterized by the presence of a spermaceti organ. However, this organ is much reduced in kogiids and may have become functionally different. Here we describe a fossil kogiid from the late Miocene of Panama and we explore the evolutionary history of the group with special attention to this evolutionary reduction. The fossil consists of cranial material from the late Tortonian (~7.5 Ma) Piña facies of the Chagres Formation in Panama. Detailed comparison with other fossil and extant kogiids and the results of a phylogenetic analysis place the Panamanian kogiid, herein named Nanokogia isthmia gen. et sp. nov., as a taxon most closely related to Praekogia cedrosensis from the Messinian (~6 Ma) of Baja California and to Kogia spp. Furthermore our results show that reduction of the spermaceti organ has occurred iteratively in kogiids, once in Thalassocetus antwerpiensis in the early-middle Miocene, and more recently in Kogia spp. Additionally, we estimate the divergence between extant species of Kogia at around the late Pliocene, later than previously predicted by molecular estimates. Finally, comparison of Nanokogia with the coeval Scaphokogia cochlearis from Peru shows that these two species display a greater morphological disparity between them than that observed between the extant members of the group. We hypothesize that this reflects differences in feeding ecologies of the two species, with Nanokogia being more similar to extant Kogia. Nanokogia shows that kogiids have been part of the Neotropical marine mammal communities at least since the late Miocene, and gives us insight into the evolutionary history and origins of one of the rarest groups of living whales.

@article{doi101371journalpone0123909,
    author = "Vélez‐Juarbe, Jorge and Wood, Aaron R. and Gracia, Carlos De and Hendy, Austin",
    title = "Evolutionary Patterns among Living and Fossil Kogiid Sperm Whales: Evidence from the Neogene of Central America",
    year = "2015",
    journal = "PLoS ONE",
    abstract = "Kogiids are known by two living species, the pygmy and dwarf sperm whale (Kogia breviceps and K. sima). Both are relatively rare, and as their names suggest, they are closely related to the sperm whale, all being characterized by the presence of a spermaceti organ. However, this organ is much reduced in kogiids and may have become functionally different. Here we describe a fossil kogiid from the late Miocene of Panama and we explore the evolutionary history of the group with special attention to this evolutionary reduction. The fossil consists of cranial material from the late Tortonian (\textasciitilde 7.5 Ma) Piña facies of the Chagres Formation in Panama. Detailed comparison with other fossil and extant kogiids and the results of a phylogenetic analysis place the Panamanian kogiid, herein named Nanokogia isthmia gen. et sp. nov., as a taxon most closely related to Praekogia cedrosensis from the Messinian (\textasciitilde 6 Ma) of Baja California and to Kogia spp. Furthermore our results show that reduction of the spermaceti organ has occurred iteratively in kogiids, once in Thalassocetus antwerpiensis in the early-middle Miocene, and more recently in Kogia spp. Additionally, we estimate the divergence between extant species of Kogia at around the late Pliocene, later than previously predicted by molecular estimates. Finally, comparison of Nanokogia with the coeval Scaphokogia cochlearis from Peru shows that these two species display a greater morphological disparity between them than that observed between the extant members of the group. We hypothesize that this reflects differences in feeding ecologies of the two species, with Nanokogia being more similar to extant Kogia. Nanokogia shows that kogiids have been part of the Neotropical marine mammal communities at least since the late Miocene, and gives us insight into the evolutionary history and origins of one of the rarest groups of living whales.",
    url = "https://doi.org/10.1371/journal.pone.0123909",
    doi = "10.1371/journal.pone.0123909",
    openalex = "W2016135345",
    references = "doi105962p358359"
}

Abstract The field of welfare science and public concern for animal welfare is growing, with the focus broadening from animals on farms to those in zoos and aquaria. Bottlenose dolphins (Tursiops truncatus) are the most common captive cetaceans, and relevant regulatory standards are principally resource-based and regarded as minimum requirements. In this study, the farm animal Welfare Quality® assessment was adapted to measure the welfare of bottlenose dolphins, with a similar proportion of animal-based measures (58.3%). The ‘C-Well® ‘ assessment included eleven criterion and 36 species-specific measures developed in situ at three marine mammal zoological facilities, tested for feasibility and accuracy, and substantiated by published literature on wild and captive dolphins and veterinary and professional expertise. C-Well® scores can be calculated for each measure or combined to achieve an overall score, which allows for the comparison of welfare among individuals, demographics, and facilities. This work represents a first step in quantifying and systematically measuring welfare among captive cetaceans and can be used as a model for future development in zoos and aquaria, as well as a means to support benchmarking, industry best practices, and certification.

@article{doi10712009627286243267,
    author = "Clegg, ILK and Borger-Turner, JL and Eskelinen, HC",
    title = "C-Well: The development of a welfare assessment index for captive bottlenose dolphins (Tursiops truncatus)",
    year = "2015",
    journal = "Animal Welfare",
    abstract = "Abstract The field of welfare science and public concern for animal welfare is growing, with the focus broadening from animals on farms to those in zoos and aquaria. Bottlenose dolphins (Tursiops truncatus) are the most common captive cetaceans, and relevant regulatory standards are principally resource-based and regarded as minimum requirements. In this study, the farm animal Welfare Quality® assessment was adapted to measure the welfare of bottlenose dolphins, with a similar proportion of animal-based measures (58.3\%). The ‘C-Well® ‘ assessment included eleven criterion and 36 species-specific measures developed in situ at three marine mammal zoological facilities, tested for feasibility and accuracy, and substantiated by published literature on wild and captive dolphins and veterinary and professional expertise. C-Well® scores can be calculated for each measure or combined to achieve an overall score, which allows for the comparison of welfare among individuals, demographics, and facilities. This work represents a first step in quantifying and systematically measuring welfare among captive cetaceans and can be used as a model for future development in zoos and aquaria, as well as a means to support benchmarking, industry best practices, and certification.",
    url = "https://doi.org/10.7120/09627286.24.3.267",
    doi = "10.7120/09627286.24.3.267",
    openalex = "W3093062764",
    references = "caut2011stable, doi1010079789402409802, doi101016japplanim200602001, doi101016s0003347205806402, doi101017s096272860001438x, doi10107997808519900400000, doi101111j174876921986tb00026x, doi101242jeb045104, doi1023073798912, doi102527199169104167x, doi103168jds20092431, openalexw2155353950"
}

Late 19th century technological advances for capturing whales, when combined with the expansion of processing capabilities in the early 20th century, created an industry that could catch and quickly render virtually any whale in any ocean. Here, using the current International Whaling Commission (IWC) database and other sources, we provide the fi rst accounting of the total global catch by industrial whaling operations in the 20th century. In sum, we estimate that nearly 2.9 million large whales were killed and processed during the period 1900–99. Of this total, 276,442 were killed in the North Atlantic, 563,696 in the North Pacifi c, and 2,053,956 in the Southern Hemisphere. The years 1925–39 in the Southern Hemisphere and 1946–75 in both hemispheres saw the highest totals of whales killed. For the entire 20th century, the largest catches were of fi n, Balaenoptera physalus, and sperm whales, Physeter macrocephalus, with 874,068 and 761,523 taken, respectively; these comprised more than half the total of all large whales taken. As noted in other publications, when one species began to decline, another was sought and hunted to take its place. In addition to reported catches, it is now known that the USSR conducted illegal whaling for more than 30 years. The true Soviet catch totals for the Southern Hemisphere were corrected some years ago, and a more recent assessment of the actual number of whales killed by Soviet factory fl eet ships in the North Pacifi c between 1948 and 1979 has provided us with more accurate numbers with which to calculate the overall global catch. The estimate for the total global catch by the USSR is 534,204 whales, of which 178,811 were not reported to the IWC.

@article{doi107755mfr7643,
    author = "Rocha, Robert C. and Clapham, Phillip J. and Ivashchenko, Yulia V.",
    title = "Emptying the Oceans: A Summary of Industrial Whaling Catches in the 20th Century",
    year = "2015",
    journal = "Marine Fisheries Review",
    abstract = "Late 19th century technological advances for capturing whales, when combined with the expansion of processing capabilities in the early 20th century, created an industry that could catch and quickly render virtually any whale in any ocean. Here, using the current International Whaling Commission (IWC) database and other sources, we provide the fi rst accounting of the total global catch by industrial whaling operations in the 20th century. In sum, we estimate that nearly 2.9 million large whales were killed and processed during the period 1900–99. Of this total, 276,442 were killed in the North Atlantic, 563,696 in the North Pacifi c, and 2,053,956 in the Southern Hemisphere. The years 1925–39 in the Southern Hemisphere and 1946–75 in both hemispheres saw the highest totals of whales killed. For the entire 20th century, the largest catches were of fi n, Balaenoptera physalus, and sperm whales, Physeter macrocephalus, with 874,068 and 761,523 taken, respectively; these comprised more than half the total of all large whales taken. As noted in other publications, when one species began to decline, another was sought and hunted to take its place. In addition to reported catches, it is now known that the USSR conducted illegal whaling for more than 30 years. The true Soviet catch totals for the Southern Hemisphere were corrected some years ago, and a more recent assessment of the actual number of whales killed by Soviet factory fl eet ships in the North Pacifi c between 1948 and 1979 has provided us with more accurate numbers with which to calculate the overall global catch. The estimate for the total global catch by the USSR is 534,204 whales, of which 178,811 were not reported to the IWC.",
    url = "https://doi.org/10.7755/mfr.76.4.3",
    doi = "10.7755/mfr.76.4.3",
    openalex = "W2331183246",
    references = "doi101111j13652907200700106x"
}

@incollection{crossref2016cetaceans,
    title = "Cetaceans",
    year = "2016",
    booktitle = "Britain's Mammals",
    url = "https://doi.org/10.1515/9781400866038-021",
    doi = "10.1515/9781400866038-021",
    pages = "280-310"
}

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:- striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, south-west Iberian Peninsula) are global PCB "hotspots" for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.

@article{doi101038srep18573,
    author = "Jepson, Paul D. and Deaville, Rob and Barber, Jonathan L. and Aguilar, Álex and Borrell, Asunción and Murphy, Sinéad and Barry, Jon and Brownlow, Andrew and Barnett, James and Berrow, Simon and Cunningham, Andrew A. and Davison, Nicholas J. and ten Doeschate, Mariel and Esteban, Ruth and Ferreira, Marisa and Foote, Andrew D. and Genov, Tilen and Giménez, Joan and Loveridge, Jan and Llavona, Ángela and Martín, Vidal and Maxwell, David and Papachlimitzou, Alexandra and Penrose, Rod and Perkins, Matthew W. and Smith, Brian and de Stephanis, Renaud and Tregenza, Nick and Verborgh, Philippe and Fernández, Antonio and Law, Robin J.",
    title = "PCB pollution continues to impact populations of orcas and other dolphins in European waters",
    year = "2016",
    journal = "Scientific Reports",
    abstract = {Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:- striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, south-west Iberian Peninsula) are global PCB "hotspots" for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.},
    url = "https://doi.org/10.1038/srep18573",
    doi = "10.1038/srep18573",
    openalex = "W2274723035",
    references = "doi101111j15231739200600338x"
}

Cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. Managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. Pursuant to the urgent need for this knowledge for the U.S. Atlantic and Gulf of Mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing and ocean models, and built habitat-based density models for 26 species and 3 multi-species guilds using distance sampling methodology. In the Atlantic, for 11 well-known species, model predictions resembled seasonal movement patterns previously suggested in the literature. For these we produced monthly mean density maps. For lesser-known taxa, and in the Gulf of Mexico, where seasonal movements were less well described, we produced year-round mean density maps. The results revealed high regional differences in small delphinoid densities, confirmed the importance of the continental slope to large delphinoids and of canyons and seamounts to beaked and sperm whales, and quantified seasonal shifts in the densities of migratory baleen whales. The density maps, freely available online, are the first for these regions to be published in the peer-reviewed literature.

@article{doi101038srep22615,
    author = "Roberts, Jason J. and Best, Benjamin D. and Mannocci, Laura and Fujioka, Ei and Halpin, Patrick N. and Palka, Debra L. and Garrison, Lance and Mullin, Keith D. and Cole, Timothy V. N. and Khan, Christin Brangwynne and McLellan, William A. and Pabst, D. Ann and Lockhart, Gwen",
    title = "Habitat-based cetacean density models for the U.S. Atlantic and Gulf of Mexico",
    year = "2016",
    journal = "Scientific Reports",
    abstract = "Cetaceans are protected worldwide but vulnerable to incidental harm from an expanding array of human activities at sea. Managing potential hazards to these highly-mobile populations increasingly requires a detailed understanding of their seasonal distributions and habitats. Pursuant to the urgent need for this knowledge for the U.S. Atlantic and Gulf of Mexico, we integrated 23 years of aerial and shipboard cetacean surveys, linked them to environmental covariates obtained from remote sensing and ocean models, and built habitat-based density models for 26 species and 3 multi-species guilds using distance sampling methodology. In the Atlantic, for 11 well-known species, model predictions resembled seasonal movement patterns previously suggested in the literature. For these we produced monthly mean density maps. For lesser-known taxa, and in the Gulf of Mexico, where seasonal movements were less well described, we produced year-round mean density maps. The results revealed high regional differences in small delphinoid densities, confirmed the importance of the continental slope to large delphinoids and of canyons and seamounts to beaked and sperm whales, and quantified seasonal shifts in the densities of migratory baleen whales. The density maps, freely available online, are the first for these regions to be published in the peer-reviewed literature.",
    url = "https://doi.org/10.1038/srep22615",
    doi = "10.1038/srep22615",
    openalex = "W2314229876",
    references = "doi103354esr00197"
}

Mammals host diverse bacterial and archaeal symbiont communities (i.e. microbiomes) that play important roles in digestive and immune system functioning, yet cetacean microbiomes remain largely unexplored, in part due to sample collection difficulties. Here, fecal samples from stranded pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales were used to characterize the gut microbiomes of two closely-related species with similar diets. 16S rRNA gene sequencing revealed diverse microbial communities in kogiid whales dominated by Firmicutes and Bacteroidetes. Core symbiont taxa were affiliated with phylogenetic lineages capable of fermentative metabolism and sulfate respiration, indicating potential symbiont contributions to energy acquisition during prey digestion. The diversity and phylum-level composition of kogiid microbiomes differed from those previously reported in toothed whales, which exhibited low diversity communities dominated by Proteobacteria and Actinobacteria. Community structure analyses revealed distinct gut microbiomes in K. breviceps and K. sima, driven by differential relative abundances of shared taxa, and unique microbiomes in kogiid hosts compared to other toothed and baleen whales, driven by differences in symbiont membership. These results provide insight into the diversity, composition and structure of kogiid gut microbiomes and indicate that host identity plays an important role in structuring cetacean microbiomes, even at fine-scale taxonomic levels.

@article{doi101038s4159801707425z,
    author = "Erwin, Patrick M. and Rhodes, Ryan G. and Kiser, Kevin B. and Keenan, Tiffany F. and McLellan, William A. and Pabst, D. Ann",
    title = "High diversity and unique composition of gut microbiomes in pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales",
    year = "2017",
    journal = "Scientific Reports",
    abstract = "Mammals host diverse bacterial and archaeal symbiont communities (i.e. microbiomes) that play important roles in digestive and immune system functioning, yet cetacean microbiomes remain largely unexplored, in part due to sample collection difficulties. Here, fecal samples from stranded pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales were used to characterize the gut microbiomes of two closely-related species with similar diets. 16S rRNA gene sequencing revealed diverse microbial communities in kogiid whales dominated by Firmicutes and Bacteroidetes. Core symbiont taxa were affiliated with phylogenetic lineages capable of fermentative metabolism and sulfate respiration, indicating potential symbiont contributions to energy acquisition during prey digestion. The diversity and phylum-level composition of kogiid microbiomes differed from those previously reported in toothed whales, which exhibited low diversity communities dominated by Proteobacteria and Actinobacteria. Community structure analyses revealed distinct gut microbiomes in K. breviceps and K. sima, driven by differential relative abundances of shared taxa, and unique microbiomes in kogiid hosts compared to other toothed and baleen whales, driven by differences in symbiont membership. These results provide insight into the diversity, composition and structure of kogiid gut microbiomes and indicate that host identity plays an important role in structuring cetacean microbiomes, even at fine-scale taxonomic levels.",
    url = "https://doi.org/10.1038/s41598-017-07425-z",
    doi = "10.1038/s41598-017-07425-z",
    openalex = "W2741520717",
    references = "doi105962p358359"
}

Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting Hong Kong waters are thought to be among the world's most anthropogenically impacted coastal delphinids. We have conducted a 5-year (2010-2014) photo-ID study and performed the first in this region comprehensive mark-recapture analysis applying a suite of open population models and robust design models. Cormack-Jolly-Seber (CJS) models suggested a significant transient effect and seasonal variation in apparent survival probabilities as result of a fluid movement beyond the study area. Given the spatial restrictions of our study, limited by an administrative border, if emigration was to be considered negligible the estimated survival rate of adults was 0.980. Super-population estimates indicated that at least 368 dolphins used Hong Kong waters as part of their range. Closed robust design models suggested an influx of dolphins from winter to summer and increased site fidelity in summer; and outflux, although less prominent, during summer-winter intervals. Abundance estimates in summer (N = 144-231) were higher than that in winter (N = 87-111), corresponding to the availability of prey resources which in Hong Kong waters peaks during summer months. We point out that the current population monitoring strategy used by the Hong Kong authorities is ill-suited for a timely detection of a population change and should be revised.

@article{doi101371journalpone0174029,
    author = "Chan, Stephen C. Y. and Karczmarski, Leszek",
    title = "Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kong: Modelling demographic parameters with mark-recapture techniques",
    year = "2017",
    journal = "PLoS ONE",
    abstract = "Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting Hong Kong waters are thought to be among the world's most anthropogenically impacted coastal delphinids. We have conducted a 5-year (2010-2014) photo-ID study and performed the first in this region comprehensive mark-recapture analysis applying a suite of open population models and robust design models. Cormack-Jolly-Seber (CJS) models suggested a significant transient effect and seasonal variation in apparent survival probabilities as result of a fluid movement beyond the study area. Given the spatial restrictions of our study, limited by an administrative border, if emigration was to be considered negligible the estimated survival rate of adults was 0.980. Super-population estimates indicated that at least 368 dolphins used Hong Kong waters as part of their range. Closed robust design models suggested an influx of dolphins from winter to summer and increased site fidelity in summer; and outflux, although less prominent, during summer-winter intervals. Abundance estimates in summer (N = 144-231) were higher than that in winter (N = 87-111), corresponding to the availability of prey resources which in Hong Kong waters peaks during summer months. We point out that the current population monitoring strategy used by the Hong Kong authorities is ill-suited for a timely detection of a population change and should be revised.",
    url = "https://doi.org/10.1371/journal.pone.0174029",
    doi = "10.1371/journal.pone.0174029",
    openalex = "W2599581617",
    references = "doi1015159789882200159016"
}

The ecological role of species can vary among populations depending on local and regional differences in diet. This is particularly true for top predators such as the bottlenose dolphin (Tursiops truncatus), which exhibits a highly varied diet throughout its distribution range. Local dietary assessments are therefore critical to fully understand the role of this species within marine ecosystems, as well as its interaction with important ecosystem services such as fisheries. Here, we combined stomach content analyses (SCA) and stable isotope analyses (SIA) to describe bottlenose dolphins diet in the Gulf of Cadiz (North Atlantic Ocean). Prey items identified using SCA included European conger (Conger conger) and European hake (Merluccius merluccius) as the most important ingested prey. However, mass-balance isotopic mixing model (MixSIAR), using δ13C and δ15N, indicated that the assimilated diet consisted mainly on Sparidae species (e.g. seabream, Diplodus annularis and D. bellottii, rubberlip grunt, Plectorhinchus mediterraneus, and common pandora, Pagellus erythrinus) and a mixture of other species including European hake, mackerels (Scomber colias, S. japonicus and S. scombrus), European conger, red bandfish (Cepola macrophthalma) and European pilchard (Sardina pilchardus). These contrasting results highlight differences in the temporal and taxonomic resolution of each approach, but also point to potential differences between ingested (SCA) and assimilated (SIA) diets. Both approaches provide different insights, e.g. determination of consumed fish biomass for the management of fish stocks (SCA) or identification of important assimilated prey species to the consumer (SIA).

@article{doi101371journalpone0184673,
    author = "Giménez, Joan and Marçalo, Ana and Ramı́rez, Francisco and Verborgh, Philippe and Gauffier, Pauline and Esteban, Ruth and Nicolau, Lídia and González‐Ortegón, Enrique and Baldó, Francisco and Vílas, César and Vingada, José and Forero, Manuela G. and de Stephanis, Renaud",
    title = "Diet of bottlenose dolphins (Tursiops truncatus) from the Gulf of Cadiz: Insights from stomach content and stable isotope analyses",
    year = "2017",
    journal = "PLoS ONE",
    abstract = "The ecological role of species can vary among populations depending on local and regional differences in diet. This is particularly true for top predators such as the bottlenose dolphin (Tursiops truncatus), which exhibits a highly varied diet throughout its distribution range. Local dietary assessments are therefore critical to fully understand the role of this species within marine ecosystems, as well as its interaction with important ecosystem services such as fisheries. Here, we combined stomach content analyses (SCA) and stable isotope analyses (SIA) to describe bottlenose dolphins diet in the Gulf of Cadiz (North Atlantic Ocean). Prey items identified using SCA included European conger (Conger conger) and European hake (Merluccius merluccius) as the most important ingested prey. However, mass-balance isotopic mixing model (MixSIAR), using δ13C and δ15N, indicated that the assimilated diet consisted mainly on Sparidae species (e.g. seabream, Diplodus annularis and D. bellottii, rubberlip grunt, Plectorhinchus mediterraneus, and common pandora, Pagellus erythrinus) and a mixture of other species including European hake, mackerels (Scomber colias, S. japonicus and S. scombrus), European conger, red bandfish (Cepola macrophthalma) and European pilchard (Sardina pilchardus). These contrasting results highlight differences in the temporal and taxonomic resolution of each approach, but also point to potential differences between ingested (SCA) and assimilated (SIA) diets. Both approaches provide different insights, e.g. determination of consumed fish biomass for the management of fish stocks (SCA) or identification of important assimilated prey species to the consumer (SIA).",
    url = "https://doi.org/10.1371/journal.pone.0184673",
    doi = "10.1371/journal.pone.0184673",
    openalex = "W2755388401",
    references = "doi101016jjembe201511001"
}

Fin whales Balaenoptera physalus used to be abundant in the Strait of Gibraltar and nearby Atlantic areas until their rapid collapse due to intense whaling at the beginning of the 20th century. Recent studies seem to indicate that some fin whales, believed to belong to the North East North Atlantic (NENA) stock, now use the area to travel between the Atlantic Ocean and the Mediterranean Sea. In this study, we analyzed 15 yr of direct observations combining vessel and land-based surveys with photo-identification to characterize the migration of fin whales through the Strait. These combined observations provide a temporal and spatial analysis of the whales' movement patterns and behavioral activity. Our main findings suggest a migration of a small community of fin whales through the Strait of Gibraltar, with remarkable seasonal directionality. All whales travelled towards the Atlantic Ocean between May and October, and 69% towards the Mediterranean Sea between November and April. Observations of young whales exiting the Mediterranean Sea mainly between May and July suggest that at least part of this community is likely to calve in the basin. Due to the special sensitivity of the species to ship strikes and underwater noise, and the intense maritime traffic in the Strait of Gibraltar, we urge Spain and Morocco to cooperate through the International Maritime Organization (IMO) to ensure a safe crossing of these whales by the effective implementation and year-round extension of the existing recommendation of a seasonal vessel speed reduction to 13 knots.

@article{doi103354meps12449,
    author = "Gauffier, Pauline and Verborgh, Philippe and Giménez, Joan and Esteban, Ruth and Sierra, JM Salazar and de Stephanis, Renaud",
    title = "Contemporary migration of fin whales through the Strait of Gibraltar",
    year = "2017",
    journal = "Marine Ecology Progress Series",
    abstract = "Fin whales Balaenoptera physalus used to be abundant in the Strait of Gibraltar and nearby Atlantic areas until their rapid collapse due to intense whaling at the beginning of the 20th century. Recent studies seem to indicate that some fin whales, believed to belong to the North East North Atlantic (NENA) stock, now use the area to travel between the Atlantic Ocean and the Mediterranean Sea. In this study, we analyzed 15 yr of direct observations combining vessel and land-based surveys with photo-identification to characterize the migration of fin whales through the Strait. These combined observations provide a temporal and spatial analysis of the whales' movement patterns and behavioral activity. Our main findings suggest a migration of a small community of fin whales through the Strait of Gibraltar, with remarkable seasonal directionality. All whales travelled towards the Atlantic Ocean between May and October, and 69\% towards the Mediterranean Sea between November and April. Observations of young whales exiting the Mediterranean Sea mainly between May and July suggest that at least part of this community is likely to calve in the basin. Due to the special sensitivity of the species to ship strikes and underwater noise, and the intense maritime traffic in the Strait of Gibraltar, we urge Spain and Morocco to cooperate through the International Maritime Organization (IMO) to ensure a safe crossing of these whales by the effective implementation and year-round extension of the existing recommendation of a seasonal vessel speed reduction to 13 knots.",
    url = "https://doi.org/10.3354/meps12449",
    doi = "10.3354/meps12449",
    openalex = "W2772323082",
    references = "doi101111mms12034"
}

Little is known of the spatio-temporal occurrence of beaked whales off western Ireland, limiting the ability of Regulators to implement appropriate management and conservation measures. To address this knowledge gap, static acoustic monitoring was carried out using eight fixed bottom-mounted autonomous acoustic recorders: four from May to December 2015 on Ireland's northern slope and four from March to November 2016 on the western and southern slopes. Recorders ran for 205 to 230 days, resulting in 4.09 TB of data sampled at 250 kHz which could capture beaked whale acoustic signals. Zero-crossing-based automated detectors identified beaked whale clicks. A sample of detections was manually validated to evaluate and optimize detector performance. Analysis confirmed the occurrence of Sowerby's and Cuvier's beaked whales and Northern bottlenose whales. Northern bottlenose whale clicks occurred in late summer and autumn, but were too few to allow further analysis. Cuvier's and Sowerby's clicks occurred at all stations throughout the monitoring period. There was a significant effect of month and station (latitude) on the mean daily number of click detections for both species. Cuvier's clicks were more abundant at lower latitudes while Sowerby's were greater at higher latitudes, particularly in the spring, suggesting a spatial segregation between species, possibly driven by prey preference. Cuvier's occurrence increased in late autumn 2015 off northwest Porcupine Bank, a region of higher relative occurrence for each species. Seismic airgun shots, with daily sound exposure levels as high as 175 dB re 1 μPa2·s, did not appear to impact the mean daily number of Cuvier's or Sowerby's beaked whale click detections. This work provides insight into the significance of Irish waters for beaked whales and highlights the importance of using acoustics for beaked whale monitoring.

@article{doi101371journalpone0199431,
    author = "Kowarski, Katie and Delarue, Julien and Martin, Bruce and O’Brien, Joanne and Meade, Rossa and Cadhla, Oliver Ó and Berrow, Simon",
    title = "Signals from the deep: Spatial and temporal acoustic occurrence of beaked whales off western Ireland",
    year = "2018",
    journal = "PLoS ONE",
    abstract = "Little is known of the spatio-temporal occurrence of beaked whales off western Ireland, limiting the ability of Regulators to implement appropriate management and conservation measures. To address this knowledge gap, static acoustic monitoring was carried out using eight fixed bottom-mounted autonomous acoustic recorders: four from May to December 2015 on Ireland's northern slope and four from March to November 2016 on the western and southern slopes. Recorders ran for 205 to 230 days, resulting in 4.09 TB of data sampled at 250 kHz which could capture beaked whale acoustic signals. Zero-crossing-based automated detectors identified beaked whale clicks. A sample of detections was manually validated to evaluate and optimize detector performance. Analysis confirmed the occurrence of Sowerby's and Cuvier's beaked whales and Northern bottlenose whales. Northern bottlenose whale clicks occurred in late summer and autumn, but were too few to allow further analysis. Cuvier's and Sowerby's clicks occurred at all stations throughout the monitoring period. There was a significant effect of month and station (latitude) on the mean daily number of click detections for both species. Cuvier's clicks were more abundant at lower latitudes while Sowerby's were greater at higher latitudes, particularly in the spring, suggesting a spatial segregation between species, possibly driven by prey preference. Cuvier's occurrence increased in late autumn 2015 off northwest Porcupine Bank, a region of higher relative occurrence for each species. Seismic airgun shots, with daily sound exposure levels as high as 175 dB re 1 μPa2·s, did not appear to impact the mean daily number of Cuvier's or Sowerby's beaked whale click detections. This work provides insight into the significance of Irish waters for beaked whales and highlights the importance of using acoustics for beaked whale monitoring.",
    url = "https://doi.org/10.1371/journal.pone.0199431",
    doi = "10.1371/journal.pone.0199431",
    openalex = "W2808838122",
    references = "openalexw2546754148"
}

The cost of reproduction is a key parameter determining a species' life history strategy. Despite exhibiting some of the fastest offspring growth rates among mammals, the cost of reproduction in baleen whales is largely unknown since standard field metabolic techniques cannot be applied. We quantified the cost of reproduction for southern right whales Eubalaena australis over a 3 mo breeding season. We did this by determining the relationship between calf growth rate and maternal rate of loss in energy reserves, using repeated measurements of body volume obtained from un manned aerial vehicle photogrammetry. We recorded 1118 body volume estimates from 40 female and calf pairs over 40 to 89 d. Calves grew at a rate of 3.2 cm d-1 (SD = 0.45) in body length and 0.081 m3 d-1 (SD = 0.011) in body volume, while females decreased in volume at a rate of 0.126 m3 d-1 (SD = 0.036). The average volume conversion efficiency from female to calf was 68% (SD = 16.91). Calf growth rate was positively related to the rate of loss in maternal body volume, suggesting that maternal volume loss is proportional to the energy investment into her calf. Maternal in vestment was determined by her body size and condition, with longer and more rotund females investing more volume into their calves compared to shorter and leaner females. Lactating females lost on average 25% of their initial body volume over the 3 mo breeding season. This study demonstrates the considerable energetic cost that females face during the lactation period, and highlights the importance of sufficientmaternal energyreserves for reproduction in this capital breeding species.

@article{doi103354meps12522,
    author = "Christiansen, Fredrik and Vivier, Fabien and Charlton, Claire and Ward, Rhianne and Amerson, Ann B. and Burnell, Stephen and Bejder, Lars",
    title = "Maternal body size and condition determine calf growth rates in southern right whales",
    year = "2018",
    journal = "Marine Ecology Progress Series",
    abstract = "The cost of reproduction is a key parameter determining a species' life history strategy. Despite exhibiting some of the fastest offspring growth rates among mammals, the cost of reproduction in baleen whales is largely unknown since standard field metabolic techniques cannot be applied. We quantified the cost of reproduction for southern right whales Eubalaena australis over a 3 mo breeding season. We did this by determining the relationship between calf growth rate and maternal rate of loss in energy reserves, using repeated measurements of body volume obtained from un manned aerial vehicle photogrammetry. We recorded 1118 body volume estimates from 40 female and calf pairs over 40 to 89 d. Calves grew at a rate of 3.2 cm d-1 (SD = 0.45) in body length and 0.081 m3 d-1 (SD = 0.011) in body volume, while females decreased in volume at a rate of 0.126 m3 d-1 (SD = 0.036). The average volume conversion efficiency from female to calf was 68\% (SD = 16.91). Calf growth rate was positively related to the rate of loss in maternal body volume, suggesting that maternal volume loss is proportional to the energy investment into her calf. Maternal in vestment was determined by her body size and condition, with longer and more rotund females investing more volume into their calves compared to shorter and leaner females. Lactating females lost on average 25\% of their initial body volume over the 3 mo breeding season. This study demonstrates the considerable energetic cost that females face during the lactation period, and highlights the importance of sufficientmaternal energyreserves for reproduction in this capital breeding species.",
    url = "https://doi.org/10.3354/meps12522",
    doi = "10.3354/meps12522",
    openalex = "W2793242202",
    references = "doi101038367108a0"
}

Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behaviour of blue whales using dietary DNA metabarcoding of faecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87 % of prey DNA amplicons extracted from faecal samples from this population were sergestid shrimp, demonstrating that blue whales can locate and feed on dense swarms of other types of prey when they occur. Within the Indian Ocean sergestids are present within the top 300 m, which correlates with the deep scattering layer observed by hydroacoustics. Studies suggest that this requirement to dive deeper in search of prey likely explains the prevalence of fluke up diving within this population of blue whales relative to other parts of the globe. Furthermore, this study revealed the presence of acanthocephalan endoparasites within the stomach and intestines of the Northern Indian Ocean blue whales. This represents the first record of Acanthocephala in blue whales in the Northern Indian Ocean and highlights the need for further studies on both the ecto- and endoparasitic flora and monitoring of health of these cetaceans for their management and conservation.

@article{doi103389fmars201800104,
    author = "de Vos, Asha and Faux, Cassandra E. and Marthick, James R. and Dickinson, Joanne L. and Jarman, Simon",
    title = "New Determination of Prey and Parasite Species for Northern Indian Ocean Blue Whales",
    year = "2018",
    journal = "Frontiers in Marine Science",
    abstract = "Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behaviour of blue whales using dietary DNA metabarcoding of faecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87 \% of prey DNA amplicons extracted from faecal samples from this population were sergestid shrimp, demonstrating that blue whales can locate and feed on dense swarms of other types of prey when they occur. Within the Indian Ocean sergestids are present within the top 300 m, which correlates with the deep scattering layer observed by hydroacoustics. Studies suggest that this requirement to dive deeper in search of prey likely explains the prevalence of fluke up diving within this population of blue whales relative to other parts of the globe. Furthermore, this study revealed the presence of acanthocephalan endoparasites within the stomach and intestines of the Northern Indian Ocean blue whales. This represents the first record of Acanthocephala in blue whales in the Northern Indian Ocean and highlights the need for further studies on both the ecto- and endoparasitic flora and monitoring of health of these cetaceans for their management and conservation.",
    url = "https://doi.org/10.3389/fmars.2018.00104",
    doi = "10.3389/fmars.2018.00104",
    openalex = "W2795857720",
    references = "doi1047536jcrmv10i3637"
}

Abstract Identifying foraging variation within a population and assessing its relationship with social structure is essential to increase knowledge about the evolution of social systems. Here, we investigated individual foraging variation in bottlenose dolphins and its potential influence on their social organization. We used generalized affiliation indices and applied social network analysis to data collected over four consecutive years of research in a coastal area subject to significant use and pressure by humans. Our findings revealed variation in foraging behavior among individual bottlenose dolphins, which in turn shapes their social organization. Our results indicated that individuals that frequently foraged within human-altered areas (i.e., shellfish farms) exhibited weaker Strength, Reach, and Affinity compared to others. These bottlenose dolphins profit from a reliable and easily located food source, which may increase their energy intake and interindividual competition. In contrast, individuals that foraged less frequently within the shellfish farms occupied a central position within the network and exhibited strong associations. These individuals may benefit from increased cooperation and reduced intragroup competition, thus increasing learning and information sharing, as they may face a patchy and irregular distribution of prey. We also demonstrated that bottlenose dolphins preferred to affiliate with other individuals with similar foraging strategies (i.e., homophily), which could promote, through time, a segregation of the population into behaviorally distinct groups. These findings provide valuable insight into the evolution of bottlenose dolphin social systems and their response to human-induced changes in the marine environment.

@article{doi101093behecoarz160,
    author = "Methion, Séverine and López, Bruno Díaz",
    title = "Individual foraging variation drives social organization in bottlenose dolphins",
    year = "2019",
    journal = "Behavioral Ecology",
    abstract = "Abstract Identifying foraging variation within a population and assessing its relationship with social structure is essential to increase knowledge about the evolution of social systems. Here, we investigated individual foraging variation in bottlenose dolphins and its potential influence on their social organization. We used generalized affiliation indices and applied social network analysis to data collected over four consecutive years of research in a coastal area subject to significant use and pressure by humans. Our findings revealed variation in foraging behavior among individual bottlenose dolphins, which in turn shapes their social organization. Our results indicated that individuals that frequently foraged within human-altered areas (i.e., shellfish farms) exhibited weaker Strength, Reach, and Affinity compared to others. These bottlenose dolphins profit from a reliable and easily located food source, which may increase their energy intake and interindividual competition. In contrast, individuals that foraged less frequently within the shellfish farms occupied a central position within the network and exhibited strong associations. These individuals may benefit from increased cooperation and reduced intragroup competition, thus increasing learning and information sharing, as they may face a patchy and irregular distribution of prey. We also demonstrated that bottlenose dolphins preferred to affiliate with other individuals with similar foraging strategies (i.e., homophily), which could promote, through time, a segregation of the population into behaviorally distinct groups. These findings provide valuable insight into the evolution of bottlenose dolphin social systems and their response to human-induced changes in the marine environment.",
    url = "https://doi.org/10.1093/beheco/arz160",
    doi = "10.1093/beheco/arz160",
    openalex = "W2972810271",
    references = "doi101111j13652907200800133x"
}

The evolution of cetaceans, from their early transition to an aquatic lifestyle to their subsequent diversification, has been the subject of numerous studies. However, although the higher-level relationships among cetacean families have been largely settled, several aspects of the systematics within these groups remain unresolved. Problematic clades include the oceanic dolphins (37 spp.), which have experienced a recent rapid radiation, and the beaked whales (22 spp.), which have not been investigated in detail using nuclear loci. The combined application of high-throughput sequencing with techniques that target specific genomic sequences provide a powerful means of rapidly generating large volumes of orthologous sequence data for use in phylogenomic studies. To elucidate the phylogenetic relationships within the Cetacea, we combined sequence capture with Illumina sequencing to generate data for $\sim $3200 protein-coding genes for 68 cetacean species and their close relatives including the pygmy hippopotamus. By combining data from $>$38,000 exons with existing sequences from 11 cetaceans and seven outgroup taxa, we produced the first comprehensive comparative genomic data set for cetaceans, spanning 6,527,596 aligned base pairs (bp) and 89 taxa. Phylogenetic trees reconstructed with maximum likelihood and Bayesian inference of concatenated loci, as well as with coalescence analyses of individual gene trees, produced mostly concordant and well-supported trees. Our results completely resolve the relationships among beaked whales as well as the contentious relationships among oceanic dolphins, especially the problematic subfamily Delphinidae. We carried out Bayesian estimation of species divergence times using MCMCTree and compared our complete data set to a subset of clocklike genes. Analyses using the complete data set consistently showed less variance in divergence times than the reduced data set. In addition, integration of new fossils (e.g., Mystacodon selenensis) indicates that the diversification of Crown Cetacea began before the Late Eocene and the divergence of Crown Delphinidae as early as the Middle Miocene. [Cetaceans; phylogenomics; Delphinidae; Ziphiidae; dolphins; whales.].

@article{doi101093sysbiosyz068,
    author = "McGowen, Michael R. and Tsagkogeorga, Georgia and Álvarez-Carretero, Sandra and dos Reis, Mario and Struebig, Monika and Deaville, Robert and Jepson, Paul D. and Jarman, Simon and Polanowski, Andrea and Morin, Phillip A. and Rossiter, Stephen J.",
    title = "Phylogenomic Resolution of the Cetacean Tree of Life Using Target Sequence Capture",
    year = "2019",
    journal = "Systematic Biology",
    abstract = "The evolution of cetaceans, from their early transition to an aquatic lifestyle to their subsequent diversification, has been the subject of numerous studies. However, although the higher-level relationships among cetacean families have been largely settled, several aspects of the systematics within these groups remain unresolved. Problematic clades include the oceanic dolphins (37 spp.), which have experienced a recent rapid radiation, and the beaked whales (22 spp.), which have not been investigated in detail using nuclear loci. The combined application of high-throughput sequencing with techniques that target specific genomic sequences provide a powerful means of rapidly generating large volumes of orthologous sequence data for use in phylogenomic studies. To elucidate the phylogenetic relationships within the Cetacea, we combined sequence capture with Illumina sequencing to generate data for $\sim $3200 protein-coding genes for 68 cetacean species and their close relatives including the pygmy hippopotamus. By combining data from $>$38,000 exons with existing sequences from 11 cetaceans and seven outgroup taxa, we produced the first comprehensive comparative genomic data set for cetaceans, spanning 6,527,596 aligned base pairs (bp) and 89 taxa. Phylogenetic trees reconstructed with maximum likelihood and Bayesian inference of concatenated loci, as well as with coalescence analyses of individual gene trees, produced mostly concordant and well-supported trees. Our results completely resolve the relationships among beaked whales as well as the contentious relationships among oceanic dolphins, especially the problematic subfamily Delphinidae. We carried out Bayesian estimation of species divergence times using MCMCTree and compared our complete data set to a subset of clocklike genes. Analyses using the complete data set consistently showed less variance in divergence times than the reduced data set. In addition, integration of new fossils (e.g., Mystacodon selenensis) indicates that the diversification of Crown Cetacea began before the Late Eocene and the divergence of Crown Delphinidae as early as the Middle Miocene. [Cetaceans; phylogenomics; Delphinidae; Ziphiidae; dolphins; whales.].",
    url = "https://doi.org/10.1093/sysbio/syz068",
    doi = "10.1093/sysbio/syz068",
    openalex = "W2981705970",
    references = "doi101098rsbl20070292, doi1026879424"
}

Abstract Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardized and systematic aerial and vessel surveys, with recorded animal densities interpolated across study areas. However, distribution maps at basin and monthly scales have previously not been possible because individual surveys have restricted spatial and temporal coverage. This study develops an alternative approach consisting of: (a) collating diverse survey data to maximize spatial and temporal coverage, (b) using detection functions to estimate variation in the surface area covered (km 2) among these surveys, standardizing measurements of effort and animal densities, and (c) developing species distribution models (SDM) that overcome issues with heterogeneous and uneven coverage. 2.68 million km of survey data in the North‐East Atlantic between 1980 and 2018 were collated and standardized. SDM using Generalized Linear Models and General Estimating Equations in a hurdle approach were developed. Distribution maps were then created for 12 cetacean and 12 seabird species at 10 km and monthly resolution. Qualitative and quantitative assessment indicated good model performance. Synthesis and applications. This study provides the largest ever collation and standardization of diverse survey data for cetaceans and seabirds, and the most comprehensive distribution maps of these taxa in the North‐East Atlantic. These distribution maps have numerous applications including the identification of important areas needing protection, and the quantification of overlap between vulnerable species and anthropogenic activities. This study demonstrates how the analysis of existing and diverse survey data can meet conservation and marine management needs.

@article{doi1011111365266413525,
    author = "Waggitt, James J. and Evans, Peter G. H. and Andrade, Joana and Banks, Alex N. and Boisseau, Oliver and Bolton, Mark and Bradbury, Gareth and Brereton, Tom and Camphuysen, Cornelis Jan and Durinck, Jan and Felce, Tom and Fijn, Ruben and García‐Barón, Isabel and Garthe, Stefan and Geelhoed, S.C.V. and Gilles, Anita and Goodall, Martin and Haelters, J. and Hamilton, Sally and Hartny‐Mills, Lauren and Hodgins, Nicola K. and James, Kathy and Jessopp, Mark and Kavanagh, Ailbhe S. and Leopold, M.F. and Lohrengel, Katrin and Louzao, Maite and Markones, Nele and Martínez-Cedeira, Jose and Cadhla, Oliver Ó and Perry, Sarah L. and Pierce, Graham J. and Ridoux, Vincent and Robinson, Kevin P. and Santos, M.B. and Saavedra, Camilo and Skov, Henrik and Stienen, Eric and Sveegaard, Signe and Thompson, Paul M. and Vanermen, Nicolas and Wall, Dave and Webb, Andy and Wilson, Jared and Wanless, Sarah and Hiddink, Jan Geert",
    title = "Distribution maps of cetacean and seabird populations in the North‐East Atlantic",
    year = "2019",
    journal = "Journal of Applied Ecology",
    abstract = "Abstract Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardized and systematic aerial and vessel surveys, with recorded animal densities interpolated across study areas. However, distribution maps at basin and monthly scales have previously not been possible because individual surveys have restricted spatial and temporal coverage. This study develops an alternative approach consisting of: (a) collating diverse survey data to maximize spatial and temporal coverage, (b) using detection functions to estimate variation in the surface area covered (km 2) among these surveys, standardizing measurements of effort and animal densities, and (c) developing species distribution models (SDM) that overcome issues with heterogeneous and uneven coverage. 2.68 million km of survey data in the North‐East Atlantic between 1980 and 2018 were collated and standardized. SDM using Generalized Linear Models and General Estimating Equations in a hurdle approach were developed. Distribution maps were then created for 12 cetacean and 12 seabird species at 10 km and monthly resolution. Qualitative and quantitative assessment indicated good model performance. Synthesis and applications. This study provides the largest ever collation and standardization of diverse survey data for cetaceans and seabirds, and the most comprehensive distribution maps of these taxa in the North‐East Atlantic. These distribution maps have numerous applications including the identification of important areas needing protection, and the quantification of overlap between vulnerable species and anthropogenic activities. This study demonstrates how the analysis of existing and diverse survey data can meet conservation and marine management needs.",
    url = "https://doi.org/10.1111/1365-2664.13525",
    doi = "10.1111/1365-2664.13525",
    openalex = "W2981341734",
    references = "doi101016jbiocon201802021"
}

Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combined published results from 10 bycatch sampling programmes in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100 000 ind. yr -1 during 2004-2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, or of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean.

@article{doi103354esr01008,
    author = "Anderson, RC and Herrera, Mercedes and Ilangakoon, AD and Koya, K. Muhammed and Moazzam, Muhammad and Mustika, Putu Liza Kusuma and Sutaria, DN",
    title = "Cetacean bycatch in Indian Ocean tuna gillnet fisheries",
    year = "2019",
    journal = "Endangered Species Research",
    abstract = "Pelagic gillnet (driftnet) fisheries account for some 34\% of Indian Ocean tuna catches. We combined published results from 10 bycatch sampling programmes in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100 000 ind. yr -1 during 2004-2006, but has declined by over 15\% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, or of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13\% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96\% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean.",
    url = "https://doi.org/10.3354/esr01008",
    doi = "10.3354/esr01008",
    openalex = "W2984274190",
    references = "doi1047536jcrmv11i1630, doi1047536jcrmv12i2573"
}

Fisheries may generate new feeding opportunities for marine predators, which switch foraging behaviour to depredation when they feed on fish directly from fishing gear. However, the role of diet in the propensity of individuals to depredate and whether the depredated resource is artificial or part of the natural diet of individuals is often unclear. Using stable isotopes, this study investigated the importance of the commercially exploited Patagonian toothfish Dissostichus eleginoides in the diet of generalist subantarctic killer whales Orcinus orca depredating this fish at Crozet (45S, 50E). The isotopic niche of these killer whales was large and overlapped with that of sperm whales Physeter macrocephalus from the same region, which feed on toothfish both naturally and through depredation. There was no isotopic difference between killer whales that depredated toothfish and those that did not. Isotopic mixing models indicated that prey groups including large/medium sized toothfish and elephant seal Mirounga leonina pups represented ~60% of the diet relative to prey groups including penguins, baleen whales and coastal fish. These results indicate that toothfish are an important natural prey item of Crozet killer whales and that switching to depredation primarily occurs when fisheries facilitate access to that resource. This study suggests that toothfish, as a commercial species, may also have a key role as prey for top predators in subantarctic ecosystems. Therefore, assessing the extent to which predators use that resource naturally or from fisheries is now needed to improve both fish stock management and species conservation strategies.

@article{doi103354meps12894,
    author = "Tixier, Paul and Giménez, Joan and Reisinger, Ryan R and Méndez‐Fernandez, Paula and Arnould, JPY and Cherel, Yves and Guinet, Christophe",
    title = "Importance of toothfish in the diet of generalist subantarctic killer whales: implications for fisheries interactions",
    year = "2019",
    journal = "Marine Ecology Progress Series",
    abstract = "Fisheries may generate new feeding opportunities for marine predators, which switch foraging behaviour to depredation when they feed on fish directly from fishing gear. However, the role of diet in the propensity of individuals to depredate and whether the depredated resource is artificial or part of the natural diet of individuals is often unclear. Using stable isotopes, this study investigated the importance of the commercially exploited Patagonian toothfish Dissostichus eleginoides in the diet of generalist subantarctic killer whales Orcinus orca depredating this fish at Crozet (45S, 50E). The isotopic niche of these killer whales was large and overlapped with that of sperm whales Physeter macrocephalus from the same region, which feed on toothfish both naturally and through depredation. There was no isotopic difference between killer whales that depredated toothfish and those that did not. Isotopic mixing models indicated that prey groups including large/medium sized toothfish and elephant seal Mirounga leonina pups represented \textasciitilde 60\% of the diet relative to prey groups including penguins, baleen whales and coastal fish. These results indicate that toothfish are an important natural prey item of Crozet killer whales and that switching to depredation primarily occurs when fisheries facilitate access to that resource. This study suggests that toothfish, as a commercial species, may also have a key role as prey for top predators in subantarctic ecosystems. Therefore, assessing the extent to which predators use that resource naturally or from fisheries is now needed to improve both fish stock management and species conservation strategies.",
    url = "https://doi.org/10.3354/meps12894",
    doi = "10.3354/meps12894",
    openalex = "W2913345874",
    references = "doi101016jjembe201511001"
}

Pygmy sperm whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) are deep diving cetaceans that commonly strand along the coast of the southeast US, but that are difficult to study visually at sea because of their elusive behavior. Conventional visual surveys are thought to significantly underestimate the presence of Kogia and they have proven difficult to approach for tracking and tagging. An approach is presented for density estimation of signals presumed to be from Kogia spp. based on passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period following the Deepwater Horizon oil spill (2010)(2011)(2012)(2013). Both species of Kogia are known to inhabit the GOM, although it is not possible to acoustically separate the two based on available knowledge of their echolocation clicks. An increasing interannual density trend is suggested for animals near the primary zone of impact of the oil spill, and to the southeast of the spill. Densities were estimated based on both counting individual echolocation clicks and counting the presence of groups of animals during one-min time windows. Densities derived from acoustic monitoring at three sites are all substantially higher (4-16 animals/1000 km 2) than those that have been derived for Kogia from line transect visual surveys in the same region (0.5 animals/1000 km 2). The most likely explanation for the observed discrepancy is that the visual surveys are underestimating Kogia spp. density, due to the assumption of perfect detectability on the survey trackline. We present an alternative approach for density estimation, one that derives echolocation and behavioral parameters based on comparison of modeled and observed sound received levels at sites of varying depth.

@article{doi103389fmars201900066,
    author = "Hildebrand, John A. and Frasier, Kaitlin E. and Baumann‐Pickering, Simone and Wiggins, Sean M. and Merkens, Karlina and Garrison, Lance and Soldevilla, Melissa S. and McDonald, Mark A.",
    title = "Assessing Seasonality and Density From Passive Acoustic Monitoring of Signals Presumed to be From Pygmy and Dwarf Sperm Whales in the Gulf of Mexico",
    year = "2019",
    journal = "Frontiers in Marine Science",
    abstract = "Pygmy sperm whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) are deep diving cetaceans that commonly strand along the coast of the southeast US, but that are difficult to study visually at sea because of their elusive behavior. Conventional visual surveys are thought to significantly underestimate the presence of Kogia and they have proven difficult to approach for tracking and tagging. An approach is presented for density estimation of signals presumed to be from Kogia spp. based on passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period following the Deepwater Horizon oil spill (2010)(2011)(2012)(2013). Both species of Kogia are known to inhabit the GOM, although it is not possible to acoustically separate the two based on available knowledge of their echolocation clicks. An increasing interannual density trend is suggested for animals near the primary zone of impact of the oil spill, and to the southeast of the spill. Densities were estimated based on both counting individual echolocation clicks and counting the presence of groups of animals during one-min time windows. Densities derived from acoustic monitoring at three sites are all substantially higher (4-16 animals/1000 km 2) than those that have been derived for Kogia from line transect visual surveys in the same region (0.5 animals/1000 km 2). The most likely explanation for the observed discrepancy is that the visual surveys are underestimating Kogia spp. density, due to the assumption of perfect detectability on the survey trackline. We present an alternative approach for density estimation, one that derives echolocation and behavioral parameters based on comparison of modeled and observed sound received levels at sites of varying depth.",
    url = "https://doi.org/10.3389/fmars.2019.00066",
    doi = "10.3389/fmars.2019.00066",
    openalex = "W2915692351",
    references = "doi105962p358359"
}

When the Omura’s whale (Balaenoptera omurai) was first described in 2003, it was known from only three locations: the southern Sea of Japan, and the vicinities of the Cocos (Keeling) Islands and Solomon Islands. Work over the following decade suggested a range limited to the Indo-Pacific, but more recent discoveries in the western Indian Ocean and Atlantic Ocean suggested a more widespread range than previously thought. Here we use all available sources of information, including published papers, unpublished reports, and web-based accounts, substantiated through genetic, morphological, photographic and acoustic documentation, to complile accounts of Omura’s whales globally. Reports increased precipitously since 2015 after publication of the first detailed external description of the species, reflecting the impact of the recently elevated awareness of the species. We report 161 accounts from 26 locales in the waters of 21 range states, and found that the species is widely distributed in primarily tropical and warm-temperate locations. Currently it is known from all ocean basins with the exception of the central and eastern Pacific. The majority of accounts remain in the eastern Indo-Pacific suggesting a potentially recent range expansion from this region. There is a strong tendency towards a coastal and neritic distribution, although there are also several pelagic records. A predominantly near coastal distribution places Omura’s whale at risk from anthropogenic activities throughout its range, and its tropical distribution in often remote and poorly monitored areas makes adequately documenting and assessing threats challenging. We assess documented threats in light of the reported species’ range, and found threats from, at minimum, ship strikes, fisheries bycatch and entanglement, local directed hunting, petroleum exploration (seismic surveys), and coastal industrial development. Current evidence indicates that at least some populations are non-migratory with local, potentially restricted ranges. Furthermore, there is low genetic diversity documented throughout its global distribution. Given the species may be characterized by small local populations, it may be particularly vulnerable to impacts from existing regional anthropogenic threats. We recommend that focused work be conducted to locate and study local populations, assess potential population isolation, and determine conservation status and specific anthropogenic threats across the species’ range.

@article{doi103389fmars201900067,
    author = "Cerchio, Salvatore and Yamada, Tadasu K. and Brownell, Robert L.",
    title = "Global Distribution of Omura’s Whales (Balaenoptera omurai) and Assessment of Range-Wide Threats",
    year = "2019",
    journal = "Frontiers in Marine Science",
    abstract = "When the Omura’s whale (Balaenoptera omurai) was first described in 2003, it was known from only three locations: the southern Sea of Japan, and the vicinities of the Cocos (Keeling) Islands and Solomon Islands. Work over the following decade suggested a range limited to the Indo-Pacific, but more recent discoveries in the western Indian Ocean and Atlantic Ocean suggested a more widespread range than previously thought. Here we use all available sources of information, including published papers, unpublished reports, and web-based accounts, substantiated through genetic, morphological, photographic and acoustic documentation, to complile accounts of Omura’s whales globally. Reports increased precipitously since 2015 after publication of the first detailed external description of the species, reflecting the impact of the recently elevated awareness of the species. We report 161 accounts from 26 locales in the waters of 21 range states, and found that the species is widely distributed in primarily tropical and warm-temperate locations. Currently it is known from all ocean basins with the exception of the central and eastern Pacific. The majority of accounts remain in the eastern Indo-Pacific suggesting a potentially recent range expansion from this region. There is a strong tendency towards a coastal and neritic distribution, although there are also several pelagic records. A predominantly near coastal distribution places Omura’s whale at risk from anthropogenic activities throughout its range, and its tropical distribution in often remote and poorly monitored areas makes adequately documenting and assessing threats challenging. We assess documented threats in light of the reported species’ range, and found threats from, at minimum, ship strikes, fisheries bycatch and entanglement, local directed hunting, petroleum exploration (seismic surveys), and coastal industrial development. Current evidence indicates that at least some populations are non-migratory with local, potentially restricted ranges. Furthermore, there is low genetic diversity documented throughout its global distribution. Given the species may be characterized by small local populations, it may be particularly vulnerable to impacts from existing regional anthropogenic threats. We recommend that focused work be conducted to locate and study local populations, assess potential population isolation, and determine conservation status and specific anthropogenic threats across the species’ range.",
    url = "https://doi.org/10.3389/fmars.2019.00067",
    doi = "10.3389/fmars.2019.00067",
    openalex = "W2913639576",
    references = "doi101111j174876921999tb00890x"
}

Six baleen whale species are found in the temperate western North Atlantic Ocean, with limited information existing on the distribution and movement patterns for most. There is mounting evidence of distributional shifts in many species, including marine mammals, likely because of climate-driven changes in ocean temperature and circulation. Previous acoustic studies examined the occurrence of minke (Balaenoptera acutorostrata) and North Atlantic right whales (NARW; Eubalaena glacialis). This study assesses the acoustic presence of humpback (Megaptera novaeangliae), sei (B. borealis), fin (B. physalus), and blue whales (B. musculus) over a decade, based on daily detections of their vocalizations. Data collected from 2004 to 2014 on 281 bottom-mounted recorders, totaling 35,033 days, were processed using automated detection software and screened for each species' presence. A published study on NARW acoustics revealed significant changes in occurrence patterns between the periods of 2004-2010 and 2011-2014; therefore, these same time periods were examined here. All four species were present from the Southeast United States to Greenland; humpback whales were also present in the Caribbean. All species occurred throughout all regions in the winter, suggesting that baleen whales are widely distributed during these months. Each of the species showed significant changes in acoustic occurrence after 2010. Similar to NARWs, sei whales had higher acoustic occurrence in mid-Atlantic regions after 2010. Fin, blue, and sei whales were more frequently detected in the northern latitudes of the study area after 2010. Despite this general northward shift, all four species were detected less on the Scotian Shelf area after 2010, matching documented shifts in prey availability in this region. A decade of acoustic observations have shown important distributional changes over the range of baleen whales, mirroring known climatic shifts and identifying new habitats that will require further protection from anthropogenic threats like fixed fishing gear, shipping, and noise pollution.

@article{doi101111gcb15191,
    author = "Davis, G. E. and Baumgartner, Mark F. and Corkeron, Peter and Bell, Joel T. and Berchok, Catherine L. and Bonnell, Julianne and Thornton, Jacqueline Bort and Brault, Solange and Buchanan, Gary and Cholewiak, Danielle and Clark, Christopher W. and Delarue, Julien and Hatch, Leila and Klinck, Holger and Kraus, Scott D. and Martin, Bruce and Mellinger, David K. and Moors‐Murphy, Hilary and Nieukirk, Sharon L. and Nowacek, Douglas P. and Parks, Susan E. and Parry, Dawn and Pegg, Nicole and Read, Andrew J. and Rice, Aaron N. and Risch, Denise and Scott, Alyssa and Soldevilla, Melissa S. and Stafford, Kathleen M. and Stanistreet, Joy E. and Summers, Erin and Todd, Sean and Parijs, Sofie M. Van",
    title = "Exploring movement patterns and changing distributions of baleen whales in the western North Atlantic using a decade of passive acoustic data",
    year = "2020",
    journal = "Global Change Biology",
    abstract = "Six baleen whale species are found in the temperate western North Atlantic Ocean, with limited information existing on the distribution and movement patterns for most. There is mounting evidence of distributional shifts in many species, including marine mammals, likely because of climate-driven changes in ocean temperature and circulation. Previous acoustic studies examined the occurrence of minke (Balaenoptera acutorostrata) and North Atlantic right whales (NARW; Eubalaena glacialis). This study assesses the acoustic presence of humpback (Megaptera novaeangliae), sei (B. borealis), fin (B. physalus), and blue whales (B. musculus) over a decade, based on daily detections of their vocalizations. Data collected from 2004 to 2014 on 281 bottom-mounted recorders, totaling 35,033 days, were processed using automated detection software and screened for each species' presence. A published study on NARW acoustics revealed significant changes in occurrence patterns between the periods of 2004-2010 and 2011-2014; therefore, these same time periods were examined here. All four species were present from the Southeast United States to Greenland; humpback whales were also present in the Caribbean. All species occurred throughout all regions in the winter, suggesting that baleen whales are widely distributed during these months. Each of the species showed significant changes in acoustic occurrence after 2010. Similar to NARWs, sei whales had higher acoustic occurrence in mid-Atlantic regions after 2010. Fin, blue, and sei whales were more frequently detected in the northern latitudes of the study area after 2010. Despite this general northward shift, all four species were detected less on the Scotian Shelf area after 2010, matching documented shifts in prey availability in this region. A decade of acoustic observations have shown important distributional changes over the range of baleen whales, mirroring known climatic shifts and identifying new habitats that will require further protection from anthropogenic threats like fixed fishing gear, shipping, and noise pollution.",
    url = "https://doi.org/10.1111/gcb.15191",
    doi = "10.1111/gcb.15191",
    openalex = "W3031222656",
    references = "doi101016jbiocon201802021"
}

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

@article{doi103354meps13356,
    author = "Fortune, SME and Ferguson, SH and Trites, Andrew W. and Leblanc, Bernard and LeMay, Valerie and Hudson, JM and Baumgartner, MF",
    title = "Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales",
    year = "2020",
    journal = "Marine Ecology Progress Series",
    abstract = "Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.",
    url = "https://doi.org/10.3354/meps13356",
    doi = "10.3354/meps13356",
    openalex = "W3022330219",
    references = "doi103354meps10029"
}

Northern right whales in the western North Atlantic number about 300 animals and have shown little sign of recovery in recent decades.Mortality and serious injury due to human activities, particularly commercial fishing and shipping, are thought to be significant factorslimiting their recovery. From 1970-1999, 45 right whale deaths were reliably documented. Sixteen of these fatalities (35.5%) were due toship collisions, and three (6.7%) were due to entanglement in fishing gear. The remainder were neonates (13; 28.9%) and ‘unknown cause’mortalities (13; 28.9%). Criteria for defining serious injuries and mortalities from entanglement or ship strikes were developed and includeany animal carrying fishing gear, cuts from entanglement or ship strike deeper than 8cm, swelling or necrosis, evidence of poor health fromsuch interactions, and, in carcasses, evidence of haematoma, haemorrhaging or broken bones. A total of 56 animals fitting the definedcriteria were documented from 1970-1999: 31 (55.4%) from entanglement and 25 (44.6%) from ship strikes. Nineteen were fatal (16 shipstrikes, 3 entanglements), 10 were possibly fatal (2 ship strikes, 8 entanglements) and 27 were non-fatal (7 ship strikes, 20 entanglements).The breakdown of potentially serious injuries by age and sex reveals no difference in levels between sexes but shows a 3.3:1 higher levelof interaction in juveniles and calves versus adults. The data show that ship strikes are more immediately lethal, but entanglements can resultin long term deterioration of an animal and may be responsible for higher levels of mortality than previously thought. Considering that someanimals become entangled, drown and never return to the surface, even these levels may be underestimated. Between 1986 and 1999, 84animals were presumed dead based on a lack of resightings for six years. There were 32 confirmed deaths during this time period suggestingthat at least as many unreported deaths occurred as carcasses were reported. Definitive actions need to be taken to reduce the level andseverity of anthropogenic injuries and deaths. Actions could include continued disentanglement efforts, gear modifications, seasonalclosures for fisheries, mandatory ship reporting, ships’ routing measures and speed restrictions for commercial shipping.

@article{doi1047536jcrmvi288,
    author = "Knowlton, Amy R. and Kraus, Scott D.",
    title = "Mortality and serious injury of northern right whales (Eubalaena glacialis) in the western North Atlantic Ocean",
    year = "2020",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "Northern right whales in the western North Atlantic number about 300 animals and have shown little sign of recovery in recent decades.Mortality and serious injury due to human activities, particularly commercial fishing and shipping, are thought to be significant factorslimiting their recovery. From 1970-1999, 45 right whale deaths were reliably documented. Sixteen of these fatalities (35.5\%) were due toship collisions, and three (6.7\%) were due to entanglement in fishing gear. The remainder were neonates (13; 28.9\%) and ‘unknown cause’mortalities (13; 28.9\%). Criteria for defining serious injuries and mortalities from entanglement or ship strikes were developed and includeany animal carrying fishing gear, cuts from entanglement or ship strike deeper than 8cm, swelling or necrosis, evidence of poor health fromsuch interactions, and, in carcasses, evidence of haematoma, haemorrhaging or broken bones. A total of 56 animals fitting the definedcriteria were documented from 1970-1999: 31 (55.4\%) from entanglement and 25 (44.6\%) from ship strikes. Nineteen were fatal (16 shipstrikes, 3 entanglements), 10 were possibly fatal (2 ship strikes, 8 entanglements) and 27 were non-fatal (7 ship strikes, 20 entanglements).The breakdown of potentially serious injuries by age and sex reveals no difference in levels between sexes but shows a 3.3:1 higher levelof interaction in juveniles and calves versus adults. The data show that ship strikes are more immediately lethal, but entanglements can resultin long term deterioration of an animal and may be responsible for higher levels of mortality than previously thought. Considering that someanimals become entangled, drown and never return to the surface, even these levels may be underestimated. Between 1986 and 1999, 84animals were presumed dead based on a lack of resightings for six years. There were 32 confirmed deaths during this time period suggestingthat at least as many unreported deaths occurred as carcasses were reported. Definitive actions need to be taken to reduce the level andseverity of anthropogenic injuries and deaths. Actions could include continued disentanglement efforts, gear modifications, seasonalclosures for fisheries, mandatory ship reporting, ships’ routing measures and speed restrictions for commercial shipping.",
    url = "https://doi.org/10.47536/jcrm.vi.288",
    doi = "10.47536/jcrm.vi.288",
    openalex = "W2110747767"
}

@incollection{crossref2021cetaceans,
    title = "Cetaceans",
    year = "2021",
    booktitle = "Britain's Mammals Updated Edition",
    url = "https://doi.org/10.1515/9780691224862-022",
    doi = "10.1515/9780691224862-022",
    pages = "280-310"
}

Abstract Ecosystems are experiencing elevated levels of disturbance, and species with narrower niches are often more vulnerable to disturbances. Niche breadth is often measured in terms of either diet or habitat use but diet and spatial use are infrequently considered in tandem. These different aspects of niche breadth potentially expose species to different types of disturbances; species with narrow dietary niches may be more affected by disturbances that alter trophic relationships, while species with narrow habitat niches may be more vulnerable to habitat loss and point‐source pollutants. We examined dietary and habitat niche breadth of common bottlenose dolphins, Tursiops truncatus truncatus, from three different nearshore sites in the Gulf of Mexico (GoM). Using stable isotopes, we determined proportional contributions of different prey groups to dolphin diets at each site and through time at one site. We used satellite‐linked telemetry at two sites to determine habitat use and site fidelity. Additionally, we examined the literature on cetacean diet, habitat use, movement, and IUCN status to determine relationships between niche breadth and population status for different species. Dolphin diets varied among sites as available prey varied, but Perciformes fish were the most frequently consumed prey. At the site for which we had temporal data, dolphins consumed more cephalopods in 2015 and 2018 but otherwise consumed primarily Perciformes fish. Dolphins had small utilization distributions and exhibited high site fidelity. Data from 31 cetacean species revealed that most species with vulnerable, threatened, or endangered IUCN statuses not only have specialized diets but also exhibit high site fidelity. Dolphins had diet characteristic of flexible generalists but were habitat specialists with high site fidelity. Dolphin populations in the GoM may have altered their diets in response to environmental changes that have altered community composition and trophic dynamics. On the other hand, their high site fidelity has exposed them to point‐source pollutants, such as oil spills, persistent organic pollutants, and freshwater. Our broader analysis of cetaceans confirmed that species with specialized diets and high site fidelity were the most vulnerable to disturbances, providing a framework to predict which nearshore dolphin populations, and cetaceans in general, are most vulnerable to environmental changes.

@article{doi101002ecs23759,
    author = "Cloyed, Carl S. and Balmer, Brian C. and Schwacke, Lori H. and Wells, Randall S. and McCabe, Elizabeth J. Berens and Barleycorn, Aaron A. and Allen, Jason B. and Rowles, Teresa K. and Smith, Cynthia R. and Takeshita, Ryan and Townsend, Forrest I. and Tumlin, Mandy C. and Zolman, Eric S. and Carmichael, Ruth H.",
    title = "Interaction between dietary and habitat niche breadth influences cetacean vulnerability to environmental disturbance",
    year = "2021",
    journal = "Ecosphere",
    abstract = "Abstract Ecosystems are experiencing elevated levels of disturbance, and species with narrower niches are often more vulnerable to disturbances. Niche breadth is often measured in terms of either diet or habitat use but diet and spatial use are infrequently considered in tandem. These different aspects of niche breadth potentially expose species to different types of disturbances; species with narrow dietary niches may be more affected by disturbances that alter trophic relationships, while species with narrow habitat niches may be more vulnerable to habitat loss and point‐source pollutants. We examined dietary and habitat niche breadth of common bottlenose dolphins, Tursiops truncatus truncatus, from three different nearshore sites in the Gulf of Mexico (GoM). Using stable isotopes, we determined proportional contributions of different prey groups to dolphin diets at each site and through time at one site. We used satellite‐linked telemetry at two sites to determine habitat use and site fidelity. Additionally, we examined the literature on cetacean diet, habitat use, movement, and IUCN status to determine relationships between niche breadth and population status for different species. Dolphin diets varied among sites as available prey varied, but Perciformes fish were the most frequently consumed prey. At the site for which we had temporal data, dolphins consumed more cephalopods in 2015 and 2018 but otherwise consumed primarily Perciformes fish. Dolphins had small utilization distributions and exhibited high site fidelity. Data from 31 cetacean species revealed that most species with vulnerable, threatened, or endangered IUCN statuses not only have specialized diets but also exhibit high site fidelity. Dolphins had diet characteristic of flexible generalists but were habitat specialists with high site fidelity. Dolphin populations in the GoM may have altered their diets in response to environmental changes that have altered community composition and trophic dynamics. On the other hand, their high site fidelity has exposed them to point‐source pollutants, such as oil spills, persistent organic pollutants, and freshwater. Our broader analysis of cetaceans confirmed that species with specialized diets and high site fidelity were the most vulnerable to disturbances, providing a framework to predict which nearshore dolphin populations, and cetaceans in general, are most vulnerable to environmental changes.",
    url = "https://doi.org/10.1002/ecs2.3759",
    doi = "10.1002/ecs2.3759",
    openalex = "W3201175424",
    references = "doi101016jjembe201511001, doi103354meps10029"
}

The highly productive waters off Iceland are an important feeding ground for baleen whales. Five balaenopterid species coexist there during the summer feeding season: the blue whale, the fin whale, the sei whale, the humpback whale and the common minke whale. For capital breeders such as baleen whales, niche partitioning and reduced interspecific competition during their stay in the feeding grounds may be critical for the completion of their annual cycles and the long-term stability of populations. Coexistence often entails spatio-temporal or trophic segregation to avoid competitive exclusion. With the aim of studying how these species share habitat and trophic resources, we analyzed the δ13C, δ15N and δ34S values in skin samples. Bayesian stable isotope mixing models to calculate compositional mixture of food sources showed that most species segregate by consuming different prey. Segregation was further enhanced by some degree of spatio-temporal exclusion. Overall, clear ecological niche partitioning was apparent between all species except between blue and fin whales. All the species consumed krill and, except for the common minke whale, this was the dominant prey. Among baleen whales, common minke whales and humpback whales were the major predators of sand eel, capelin and herring. In humpback whales, a strong reliance on krill may explain the apparently low rates of local entanglement in fishing nets as compared to other areas. Except for the blue whale, all species have shown evidence of adapting to shifts in prey availability and thus suggested capacity to cope with variability. However, in a scenario of increasing environmental variability associated to global warming, the overlap between ecological niches may have to decrease to allow long-term coexistence.

@article{doi101016jpocean2021102690,
    author = "García‐Vernet, Raquel and Borrell, Asunción and Víkingsson, Gísli A. and Halldórsson, Sverrir Daníel and Aguilar, Álex",
    title = "Ecological niche partitioning between baleen whales inhabiting Icelandic waters",
    year = "2021",
    journal = "Progress In Oceanography",
    abstract = "The highly productive waters off Iceland are an important feeding ground for baleen whales. Five balaenopterid species coexist there during the summer feeding season: the blue whale, the fin whale, the sei whale, the humpback whale and the common minke whale. For capital breeders such as baleen whales, niche partitioning and reduced interspecific competition during their stay in the feeding grounds may be critical for the completion of their annual cycles and the long-term stability of populations. Coexistence often entails spatio-temporal or trophic segregation to avoid competitive exclusion. With the aim of studying how these species share habitat and trophic resources, we analyzed the δ13C, δ15N and δ34S values in skin samples. Bayesian stable isotope mixing models to calculate compositional mixture of food sources showed that most species segregate by consuming different prey. Segregation was further enhanced by some degree of spatio-temporal exclusion. Overall, clear ecological niche partitioning was apparent between all species except between blue and fin whales. All the species consumed krill and, except for the common minke whale, this was the dominant prey. Among baleen whales, common minke whales and humpback whales were the major predators of sand eel, capelin and herring. In humpback whales, a strong reliance on krill may explain the apparently low rates of local entanglement in fishing nets as compared to other areas. Except for the blue whale, all species have shown evidence of adapting to shifts in prey availability and thus suggested capacity to cope with variability. However, in a scenario of increasing environmental variability associated to global warming, the overlap between ecological niches may have to decrease to allow long-term coexistence.",
    url = "https://doi.org/10.1016/j.pocean.2021.102690",
    doi = "10.1016/j.pocean.2021.102690",
    openalex = "W3206802074",
    references = "doi101002rcm6267"
}

This study sought to estimate the effect of an anthropogenic and climate-driven change in prey availability on the degree of individual and population specialization of a large marine predator, the fin whale (Balaenoptera physalus). We examined skin biopsies from 99 fin whales sampled in the St. Lawrence Estuary (Canada) over a nine year period (1998-2006) during which environmental change was documented. We analyzed stable isotope ratios in skin and fatty acid signatures in blubber samples of whales, as well as in seven potential prey species, and diet was quantitatively assessed using Bayesian isotopic models. An abrupt change in fin whale dietary niche coincided with a decrease in biomass of their predominant prey, Arctic krill (Thysanoessa spp.). This dietary niche widening toward generalist diets occurred in nearly 60% of sampled individuals. The fin whale population, typically composed of specialists of either krill or lipid-rich pelagic fishes, shifted toward one composed either of krill specialists or true generalists feeding on various zooplankton and fish prey. This change likely reduced intraspecific competition. In the context of the current "Atlantification" of northern water masses, our findings emphasize the importance of considering individual-specific foraging tactics and not only population or group average responses when assessing population resilience or when implementing conservation measures.

@article{doi101038s4159802196283x,
    author = "Cabrol, Jory and Lesage, Véronique and Leclerc, Alexandra and Giard, Janie and Iverson, Sara J. and Bérubé, Martine and Michaud, Robert and Nozais, Christian",
    title = "Individual and population dietary specialization decline in fin whales during a period of ecosystem shift",
    year = "2021",
    journal = "Scientific Reports",
    abstract = {This study sought to estimate the effect of an anthropogenic and climate-driven change in prey availability on the degree of individual and population specialization of a large marine predator, the fin whale (Balaenoptera physalus). We examined skin biopsies from 99 fin whales sampled in the St. Lawrence Estuary (Canada) over a nine year period (1998-2006) during which environmental change was documented. We analyzed stable isotope ratios in skin and fatty acid signatures in blubber samples of whales, as well as in seven potential prey species, and diet was quantitatively assessed using Bayesian isotopic models. An abrupt change in fin whale dietary niche coincided with a decrease in biomass of their predominant prey, Arctic krill (Thysanoessa spp.). This dietary niche widening toward generalist diets occurred in nearly 60\% of sampled individuals. The fin whale population, typically composed of specialists of either krill or lipid-rich pelagic fishes, shifted toward one composed either of krill specialists or true generalists feeding on various zooplankton and fish prey. This change likely reduced intraspecific competition. In the context of the current "Atlantification" of northern water masses, our findings emphasize the importance of considering individual-specific foraging tactics and not only population or group average responses when assessing population resilience or when implementing conservation measures.},
    url = "https://doi.org/10.1038/s41598-021-96283-x",
    doi = "10.1038/s41598-021-96283-x",
    openalex = "W3193283126",
    references = "doi101002rcm6267, doi101016jjembe201511001, doi101111mms12034"
}

Abstract Citizen science data are becoming increasingly relevant in wildlife studies, especially when obtaining data requires costly logistics. In the Arabian/Persian Gulf, baseline information about cetaceans is scarce despite their regular presence. From 2012 to 2019, a citizen science campaign conducted in the United Arab Emirates (UAE) obtained information on 1,292 cetacean sightings. These were methodically validated by experts, resulting in 1,103 records where species was confidently assigned. From the 12 species reported, we analyzed the spatial patterns of occurrence and drivers of habitat preference for the three most reported species: Tursiops aduncus (Ta 53%), Sousa plumbea (Sp 45%), and Neophocaena phocaenoides (Np 2%). Ecological niche modelling, considering seven environmental variables (physicochemical: temperature, silicate, calcite, pH; physiographic: distance from coast, bathymetry; biological: chlorophyll) showed subtle niche partitioning among the three species. Our results suggest different diets and energy requirements for Np, with Ta and Sp, segregating mostly by different patterns of space use. Specifically, Sp prefers close proximity to shore, particularly areas with complex networks of inland canals. This information provides an estimate of habitat preferences, that can be used in formulating effective conservation measures. Sp shows the narrowest area of suitable habitat and is at particular risk from habitat degradation.

@article{doi101111mms12865,
    author = "Natoli, Ada and Moura, André E. and Sillero, Neftalí",
    title = "Citizen science data of cetaceans in the Arabian/Persian Gulf: Occurrence and habitat preferences of the three most reported species",
    year = "2021",
    journal = "Marine Mammal Science",
    abstract = "Abstract Citizen science data are becoming increasingly relevant in wildlife studies, especially when obtaining data requires costly logistics. In the Arabian/Persian Gulf, baseline information about cetaceans is scarce despite their regular presence. From 2012 to 2019, a citizen science campaign conducted in the United Arab Emirates (UAE) obtained information on 1,292 cetacean sightings. These were methodically validated by experts, resulting in 1,103 records where species was confidently assigned. From the 12 species reported, we analyzed the spatial patterns of occurrence and drivers of habitat preference for the three most reported species: Tursiops aduncus (Ta 53\%), Sousa plumbea (Sp 45\%), and Neophocaena phocaenoides (Np 2\%). Ecological niche modelling, considering seven environmental variables (physicochemical: temperature, silicate, calcite, pH; physiographic: distance from coast, bathymetry; biological: chlorophyll) showed subtle niche partitioning among the three species. Our results suggest different diets and energy requirements for Np, with Ta and Sp, segregating mostly by different patterns of space use. Specifically, Sp prefers close proximity to shore, particularly areas with complex networks of inland canals. This information provides an estimate of habitat preferences, that can be used in formulating effective conservation measures. Sp shows the narrowest area of suitable habitat and is at particular risk from habitat degradation.",
    url = "https://doi.org/10.1111/mms.12865",
    doi = "10.1111/mms.12865",
    openalex = "W3198623260",
    references = "doi1047536jcrmv11i1630"
}

Investigating the feeding ecology of marine predators is critical for understanding their roles and functional importance in ecosystems. However, assessing the diet of large and wide-ranging predators can be challenging, particularly in the case of rare and elusive species. Killer whales (Orcinus orca) are large apex predators in global oceans, but very little is known about their feeding ecology in tropical ecosystems, particularly in the Caribbean Sea. Killer whales are distributed throughout the Caribbean, and are a regular target of artisanal whalers in St. Vincent and the Grenadines (West Indies). Here we investigate the feeding ecology of Caribbean killer whales using a combination of stable isotope analysis (δ 15 N, δ 13 C) and traditional ecological knowledge (TEK) data from whalers operating from St. Vincent. Potential prey data from the Caribbean region included large pelagic teleosts, sea turtles, oceanic sharks, cetaceans, and oceanic cephalopods. Mixing models suggest that the contribution of odontocete cetaceans to the diet of killer whales is the most important (overall mean contribution: 60.4%), particularly mesopelagic delphinids (Lagenodelphis hosei; 26.4%, SD = 0.14), large teuthophageous odontocetes (Physeter macrocephalus, Globicephala macrorhynchus; 20.0%, SD = 0.14), and epipelagic delphinids (Stenella attenuata; 14%, SD = 0.14). Oceanic sharks (Carcharhinus longimanus) had a contribution of 17.0% of the diet of killer whales (SD = 0.13), and other potential prey had a relatively marginal contribution. TEK data suggest that whalers believe killer whales feed almost exclusively on cetaceans, particularly odontocete species that they hunt (e.g., G. macrorhynchus). Stable isotope and TEK data were consistent to some extent, although TEK data are qualitative and based on a limited number of observations. Despite some limitations (including sample size for both methods), this study highlights the value of combining independent data sources and methodologies to investigate the ecological roles of marine predators in data-poor regions.

@article{doi103389fmars2021648421,
    author = "Kiszka, Jérémy J. and Caputo, Michelle and Méndez‐Fernandez, Paula and Fielding, Russell",
    title = "Feeding Ecology of Elusive Caribbean Killer Whales Inferred From Bayesian Stable Isotope Mixing Models and Whalers’ Ecological Knowledge",
    year = "2021",
    journal = "Frontiers in Marine Science",
    abstract = "Investigating the feeding ecology of marine predators is critical for understanding their roles and functional importance in ecosystems. However, assessing the diet of large and wide-ranging predators can be challenging, particularly in the case of rare and elusive species. Killer whales (Orcinus orca) are large apex predators in global oceans, but very little is known about their feeding ecology in tropical ecosystems, particularly in the Caribbean Sea. Killer whales are distributed throughout the Caribbean, and are a regular target of artisanal whalers in St. Vincent and the Grenadines (West Indies). Here we investigate the feeding ecology of Caribbean killer whales using a combination of stable isotope analysis (δ 15 N, δ 13 C) and traditional ecological knowledge (TEK) data from whalers operating from St. Vincent. Potential prey data from the Caribbean region included large pelagic teleosts, sea turtles, oceanic sharks, cetaceans, and oceanic cephalopods. Mixing models suggest that the contribution of odontocete cetaceans to the diet of killer whales is the most important (overall mean contribution: 60.4\%), particularly mesopelagic delphinids (Lagenodelphis hosei; 26.4\%, SD = 0.14), large teuthophageous odontocetes (Physeter macrocephalus, Globicephala macrorhynchus; 20.0\%, SD = 0.14), and epipelagic delphinids (Stenella attenuata; 14\%, SD = 0.14). Oceanic sharks (Carcharhinus longimanus) had a contribution of 17.0\% of the diet of killer whales (SD = 0.13), and other potential prey had a relatively marginal contribution. TEK data suggest that whalers believe killer whales feed almost exclusively on cetaceans, particularly odontocete species that they hunt (e.g., G. macrorhynchus). Stable isotope and TEK data were consistent to some extent, although TEK data are qualitative and based on a limited number of observations. Despite some limitations (including sample size for both methods), this study highlights the value of combining independent data sources and methodologies to investigate the ecological roles of marine predators in data-poor regions.",
    url = "https://doi.org/10.3389/fmars.2021.648421",
    doi = "10.3389/fmars.2021.648421",
    openalex = "W3159800279",
    references = "doi101016jjembe201511001, doi101111mms12034, doi103354meps10029"
}

Numerous species of cetaceans have been recorded in mixed-species groups (MSGs). By forming groups with individuals of different species, cetaceans may reduce predation risk, improve foraging, and gain social benefits. Most accounts of cetacean MSGs, however, are descriptive and little is known about their functions. Furthermore, research has been hindered by inconsistent use of terminology and the lack of a conceptual framework to guide investigations. We reviewed the cetacean literature to compare how MSGs have been termed and defined, to assess their characteristics, to evaluate what is known about their potential functions, and to provide directions for future study. In total, we reviewed 203 studies reporting observations of cetacean MSGs. These MSGs involved 54 different species, predominantly delphinids, that formed 216 different species pairs with varied morphologies and levels of relatedness. Cetacean MSGs occurred across the globe, from tropical to cold temperate seas, from shallow coastal waters to the open ocean, and varied in characteristics such as group size and frequency of occurrence. Only 27 of the reviewed studies proposed and discussed the potential functions of cetacean MSGs, suggesting reduced predation risk (5 species pairs), improved foraging (17 species pairs), and social benefits (12 species pairs) as the main drivers. In most cases, however, the factors that drive the formation of cetacean MSGs remain unknown. Amongst the reviewed studies, MSGs were referred to by various terms, often with no explicit definitions. To reduce this inconsistency, we recommend that future studies use only the term mixed-species group which we define as individuals of two or more species found in close spatial proximity due to mutual or unreciprocated attraction derived from evolutionary grouping benefits. There were also few structured investigations to confirm MSG occurrence and to analyse their potential causes and consequences. To facilitate the study of cetacean MSGs, we developed a conceptual framework that establishes diverse approaches to, firstly, distinguish MSGs from chance encounters and aggregations and to, secondly, investigate their potential functions. This is necessary if we are to advance this field of study and improve our understanding of the role that MSGs play in species and community ecology.

@article{doi103389fmars2021678173,
    author = "Syme, Jonathan and Kiszka, Jérémy J. and Parra, Guido J.",
    title = "Dynamics of Cetacean Mixed-Species Groups: A Review and Conceptual Framework for Assessing Their Functional Significance",
    year = "2021",
    journal = "Frontiers in Marine Science",
    abstract = "Numerous species of cetaceans have been recorded in mixed-species groups (MSGs). By forming groups with individuals of different species, cetaceans may reduce predation risk, improve foraging, and gain social benefits. Most accounts of cetacean MSGs, however, are descriptive and little is known about their functions. Furthermore, research has been hindered by inconsistent use of terminology and the lack of a conceptual framework to guide investigations. We reviewed the cetacean literature to compare how MSGs have been termed and defined, to assess their characteristics, to evaluate what is known about their potential functions, and to provide directions for future study. In total, we reviewed 203 studies reporting observations of cetacean MSGs. These MSGs involved 54 different species, predominantly delphinids, that formed 216 different species pairs with varied morphologies and levels of relatedness. Cetacean MSGs occurred across the globe, from tropical to cold temperate seas, from shallow coastal waters to the open ocean, and varied in characteristics such as group size and frequency of occurrence. Only 27 of the reviewed studies proposed and discussed the potential functions of cetacean MSGs, suggesting reduced predation risk (5 species pairs), improved foraging (17 species pairs), and social benefits (12 species pairs) as the main drivers. In most cases, however, the factors that drive the formation of cetacean MSGs remain unknown. Amongst the reviewed studies, MSGs were referred to by various terms, often with no explicit definitions. To reduce this inconsistency, we recommend that future studies use only the term mixed-species group which we define as individuals of two or more species found in close spatial proximity due to mutual or unreciprocated attraction derived from evolutionary grouping benefits. There were also few structured investigations to confirm MSG occurrence and to analyse their potential causes and consequences. To facilitate the study of cetacean MSGs, we developed a conceptual framework that establishes diverse approaches to, firstly, distinguish MSGs from chance encounters and aggregations and to, secondly, investigate their potential functions. This is necessary if we are to advance this field of study and improve our understanding of the role that MSGs play in species and community ecology.",
    url = "https://doi.org/10.3389/fmars.2021.678173",
    doi = "10.3389/fmars.2021.678173",
    openalex = "W3176810237",
    references = "doi101578am3012004111"
}

The Shannon Estuary in Ireland is home to a resident population of bottlenose dolphins (Tursiops truncatus) and is designated as a Special Area of Conservation under the EU Habitats Directive. It is an important industrial area, with numerous deep-water berths for shipping. Despite its high conservation value, there are few published studies on habitat use or foraging behavior of the Shannon dolphins throughout the year. The present study assessed the year-round presence and foraging activity of bottlenose dolphins at different locations in the middle and inner estuary using static acoustic monitoring. Dolphin presence was found to decrease with increased distance from the estuary mouth, i.e., where the estuary meets the Atlantic Ocean, while at the same time, foraging was found to be considerably higher in the upriver areas, suggesting the inner estuary was an important foraging area. Model predictions for seasonal, tidal and diel foraging were highly variable across locations, indicating that changes in dolphin behavior occurred over relatively small geographical scales. These results indicate that conservation efforts should consider the Shannon Estuary as a dynamic aggregation of habitats and future development initiatives should attempt to mitigate disturbance to the dolphins during important foraging periods on seasonal and diel scales.

@article{doi103390jmse9030275,
    author = "Carmen, Mathijs and Berrow, Simon and O’Brien, Joanne",
    title = "Foraging Behavior of Bottlenose Dolphins in the Shannon Estuary, Ireland as Determined through Static Acoustic Monitoring",
    year = "2021",
    journal = "Journal of Marine Science and Engineering",
    abstract = "The Shannon Estuary in Ireland is home to a resident population of bottlenose dolphins (Tursiops truncatus) and is designated as a Special Area of Conservation under the EU Habitats Directive. It is an important industrial area, with numerous deep-water berths for shipping. Despite its high conservation value, there are few published studies on habitat use or foraging behavior of the Shannon dolphins throughout the year. The present study assessed the year-round presence and foraging activity of bottlenose dolphins at different locations in the middle and inner estuary using static acoustic monitoring. Dolphin presence was found to decrease with increased distance from the estuary mouth, i.e., where the estuary meets the Atlantic Ocean, while at the same time, foraging was found to be considerably higher in the upriver areas, suggesting the inner estuary was an important foraging area. Model predictions for seasonal, tidal and diel foraging were highly variable across locations, indicating that changes in dolphin behavior occurred over relatively small geographical scales. These results indicate that conservation efforts should consider the Shannon Estuary as a dynamic aggregation of habitats and future development initiatives should attempt to mitigate disturbance to the dolphins during important foraging periods on seasonal and diel scales.",
    url = "https://doi.org/10.3390/jmse9030275",
    doi = "10.3390/jmse9030275",
    openalex = "W3133924007",
    references = "openalexw2546754148"
}

Cuvier’s and Sowerby’s beaked whales occur year-round in western Irish waters, yet remain some of the most poorly understood cetaceans in the area. Considering the importance of the area for anthropogenic activities and the sensitivity of beaked whales to noise, understanding their ecology is essential to minimise potential overlaps. To this end, fixed bottom-mounted autonomous acoustic recorders were deployed at 10 stations over four recording periods spanning from May 2015 to November 2016. Acoustic data were collected over 1934 cumulative days, for a total of 7942 h of recordings. To model the probability of presence of Cuvier’s and Sowerby’s beaked whales in the area as a function of oceanographic predictors, we used Generalised Additive Models, fitted with Generalised Estimating Equations to deal with temporal autocorrelation. To reflect prey availability, oceanographic variables acting as proxies of primary productivity and prey aggregation processes such as upwelling events and thermal fronts were selected. Our results demonstrated that oceanographic variables significantly contributed to the occurrence of Cuvier’s and Sowerby’s beaked whales (p-values between <0.001 and <0.05). The species showed similar preferences, with the exception of sdSST. The inclusion of a parameter accounting for the recorders location confirmed the existence of a latitudinal partitioning for those species in the area. This study provides a point of comparison for future research and represents an important step towards a better understanding of those elusive species.

@article{doi103390jmse9101081,
    author = "Barile, Cynthia and Berrow, Simon and O’Brien, Joanne",
    title = "Oceanographic Drivers of Cuvier’s (Ziphius cavirostris) and Sowerby’s (Mesoplodon bidens) Beaked Whales Acoustic Occurrence along the Irish Shelf Edge",
    year = "2021",
    journal = "Journal of Marine Science and Engineering",
    abstract = "Cuvier’s and Sowerby’s beaked whales occur year-round in western Irish waters, yet remain some of the most poorly understood cetaceans in the area. Considering the importance of the area for anthropogenic activities and the sensitivity of beaked whales to noise, understanding their ecology is essential to minimise potential overlaps. To this end, fixed bottom-mounted autonomous acoustic recorders were deployed at 10 stations over four recording periods spanning from May 2015 to November 2016. Acoustic data were collected over 1934 cumulative days, for a total of 7942 h of recordings. To model the probability of presence of Cuvier’s and Sowerby’s beaked whales in the area as a function of oceanographic predictors, we used Generalised Additive Models, fitted with Generalised Estimating Equations to deal with temporal autocorrelation. To reflect prey availability, oceanographic variables acting as proxies of primary productivity and prey aggregation processes such as upwelling events and thermal fronts were selected. Our results demonstrated that oceanographic variables significantly contributed to the occurrence of Cuvier’s and Sowerby’s beaked whales (p-values between <0.001 and <0.05). The species showed similar preferences, with the exception of sdSST. The inclusion of a parameter accounting for the recorders location confirmed the existence of a latitudinal partitioning for those species in the area. This study provides a point of comparison for future research and represents an important step towards a better understanding of those elusive species.",
    url = "https://doi.org/10.3390/jmse9101081",
    doi = "10.3390/jmse9101081",
    openalex = "W3203461392",
    references = "openalexw2546754148"
}

Cetaceans spend most of their time below the surface of the sea, highlighting the importance of passive acoustic monitoring as a tool to facilitate understanding and mapping their year-round spatial and temporal distributions. To increase our limited knowledge of cetacean acoustic detection patterns for the east and west coasts of Gwaii Haanas, a remote protected area on Haida Gwaii, BC, Canada, acoustic datasets recorded off SG̱ang Gwaay (Sep 2009-May 2011), Gowgaia Slope (Jul 2017-Jul 2019), and Ramsay Island (Aug 2018-Aug 2019) were analyzed. Comparing overlapping periods of visual surveys and acoustic monitoring confirmed presence of 12 cetacean species/species groups within the study region. Seasonal patterns were identified for blue, fin, humpback, grey and sperm whale acoustic signals. Killer whale and delphinid acoustic signals occurred year-round on both coasts of Haida Gwaii and showed strong diel variation. Cuvier's, Baird's, beaked whale and porpoise clicks, were identified in high-frequency recordings on the west coast. Correlations between environmental factors, chlorophyll-a and sea surface temperature, and cetacean acoustic occurrence off Gwaii Haanas were also examined. This study is the first to acoustically monitor Gwaii Haanas waters for an extended continuous period and therefore serves as a baseline from which to monitor future changes.

@article{doi101038s41598022220694,
    author = "Frouin‐Mouy, Héloïse and Mouy, Xavier and Pilkington, James and Küsel, Elizabeth T. and Nichol, Linda M. and Doniol‐Valcroze, Thomas and Lee, Lynn",
    title = "Acoustic and visual cetacean surveys reveal year-round spatial and temporal distributions for multiple species in northern British Columbia, Canada",
    year = "2022",
    journal = "Scientific Reports",
    abstract = "Cetaceans spend most of their time below the surface of the sea, highlighting the importance of passive acoustic monitoring as a tool to facilitate understanding and mapping their year-round spatial and temporal distributions. To increase our limited knowledge of cetacean acoustic detection patterns for the east and west coasts of Gwaii Haanas, a remote protected area on Haida Gwaii, BC, Canada, acoustic datasets recorded off SG̱ang Gwaay (Sep 2009-May 2011), Gowgaia Slope (Jul 2017-Jul 2019), and Ramsay Island (Aug 2018-Aug 2019) were analyzed. Comparing overlapping periods of visual surveys and acoustic monitoring confirmed presence of 12 cetacean species/species groups within the study region. Seasonal patterns were identified for blue, fin, humpback, grey and sperm whale acoustic signals. Killer whale and delphinid acoustic signals occurred year-round on both coasts of Haida Gwaii and showed strong diel variation. Cuvier's, Baird's, beaked whale and porpoise clicks, were identified in high-frequency recordings on the west coast. Correlations between environmental factors, chlorophyll-a and sea surface temperature, and cetacean acoustic occurrence off Gwaii Haanas were also examined. This study is the first to acoustically monitor Gwaii Haanas waters for an extended continuous period and therefore serves as a baseline from which to monitor future changes.",
    url = "https://doi.org/10.1038/s41598-022-22069-4",
    doi = "10.1038/s41598-022-22069-4",
    openalex = "W4308698248",
    references = "doi105962p358359"
}

Abstract Trophic ecology information about cetaceans is essential to understand their role in ecosystem dynamics. Stable isotope analysis is a valuable complementary approach to conventional methods usually applied to the study of the foraging behavior of cetaceans because it provides dietary information over different time scales and can potentially use tissues archived in scientific collections. However, the considerable increase in stable isotope analysis by a growing number of cetacean research groups demands the use of proper protocols to ensure that accurate isotopic data are obtained. We provide a theoretical background of stable isotope analysis and its application to assess cetaceans‘ trophic ecology. We review the factors that can influence isotopic measurements and propose a practical guideline with suitable techniques for sample preparation of biological tissues to be employed by researchers to yield reliability in the interpretation of isotopic data. We summarized the main assumptions and inherent limitations that can lead to confounding interpretations of isotopic data, such as species‐ and tissue‐specific discrimination factors, temporal or spatial variation in prey, and baseline isotopic values in the context of cetacean ecology. Our detailed review offers important guidance for researchers who want to use stable isotope analysis to address different ecological questions with cetacean species.

@article{doi101111mms12911,
    author = "Teixeira, Clarissa R. and Troina, Genyffer Cibele and Daura‐Jorge, Fábio G. and Simões‐Lopes, Paulo C. and Botta, Silvina",
    title = "A practical guide on stable isotope analysis for cetacean research",
    year = "2022",
    journal = "Marine Mammal Science",
    abstract = "Abstract Trophic ecology information about cetaceans is essential to understand their role in ecosystem dynamics. Stable isotope analysis is a valuable complementary approach to conventional methods usually applied to the study of the foraging behavior of cetaceans because it provides dietary information over different time scales and can potentially use tissues archived in scientific collections. However, the considerable increase in stable isotope analysis by a growing number of cetacean research groups demands the use of proper protocols to ensure that accurate isotopic data are obtained. We provide a theoretical background of stable isotope analysis and its application to assess cetaceans‘ trophic ecology. We review the factors that can influence isotopic measurements and propose a practical guideline with suitable techniques for sample preparation of biological tissues to be employed by researchers to yield reliability in the interpretation of isotopic data. We summarized the main assumptions and inherent limitations that can lead to confounding interpretations of isotopic data, such as species‐ and tissue‐specific discrimination factors, temporal or spatial variation in prey, and baseline isotopic values in the context of cetacean ecology. Our detailed review offers important guidance for researchers who want to use stable isotope analysis to address different ecological questions with cetacean species.",
    url = "https://doi.org/10.1111/mms.12911",
    doi = "10.1111/mms.12911",
    openalex = "W4211185670",
    references = "caut2011stable, doi101002rcm6267, doi101007bf00379558, doi101007s0044200312183, doi101007s004420060630x, doi1010160016703778901990, doi101016030544039090007r, doi101016jjembe201511001, doi101086343878, doi101111j13652656201101806x, doi101111mms12034, doi101139o59099, doi101146annureves18110187001453, doi101242jeb045104, doi101371journalpone0009672"
}

Dolphins play a key role in marine food webs as predators of mid-trophic-level consumers. Because of their mobility and relatively long life span, they can be used as indicators of large-scale changes in the ecosystem. In this study, we calculated the trophic position (TP) of 5 dolphin species from the Canary, Madeira and Azores Islands using bulk and compound-specific stable isotope ratios from muscle tissue to assess trophic adaptations to recent changes in the availability of feeding resources. Dolphin TP values were then compared with those of 7 other species of cetaceans from this region. Analysis of stable nitrogen isotopes in amino acids of the common dolphin indicated non-significant effects of changes in the basal resources of the food web and thus supported the use of bulk samples for TP estimations. Dolphins occupied an intermediate TP (mean: 3.91 to 4.20) between fin (3.25) and sperm whales (4.95). Species-specific TP were equivalent among islands. However, TP increased for the common dolphin and decreased for the bottlenose dolphin (the latter also becoming more oceanic) between 2000 and 2018 in the Canary Islands. These results suggest different impacts of recent changes in the oceanography and in the pelagic food web of the Macaronesian region on the trophic ecology of dolphin species.

@article{doi103354meps14176,
    author = "Bode, Antonio and Saavedra, Camilo and Álvarez-González, Miguel and Arregui, Marina and Arbelo, Manuel and Fernández, Antonio and Freitas, Luís and Silva, Mónica A. and Prieto, Rui and Azevedo, JMN and Giménez, Joan and Pierce, Graham J. and Santos, M.B.",
    title = "Trophic position of dolphins tracks recent changes in the pelagic ecosystem of the Macaronesian region (NE Atlantic)",
    year = "2022",
    journal = "Marine Ecology Progress Series",
    abstract = "Dolphins play a key role in marine food webs as predators of mid-trophic-level consumers. Because of their mobility and relatively long life span, they can be used as indicators of large-scale changes in the ecosystem. In this study, we calculated the trophic position (TP) of 5 dolphin species from the Canary, Madeira and Azores Islands using bulk and compound-specific stable isotope ratios from muscle tissue to assess trophic adaptations to recent changes in the availability of feeding resources. Dolphin TP values were then compared with those of 7 other species of cetaceans from this region. Analysis of stable nitrogen isotopes in amino acids of the common dolphin indicated non-significant effects of changes in the basal resources of the food web and thus supported the use of bulk samples for TP estimations. Dolphins occupied an intermediate TP (mean: 3.91 to 4.20) between fin (3.25) and sperm whales (4.95). Species-specific TP were equivalent among islands. However, TP increased for the common dolphin and decreased for the bottlenose dolphin (the latter also becoming more oceanic) between 2000 and 2018 in the Canary Islands. These results suggest different impacts of recent changes in the oceanography and in the pelagic food web of the Macaronesian region on the trophic ecology of dolphin species.",
    url = "https://doi.org/10.3354/meps14176",
    doi = "10.3354/meps14176",
    openalex = "W4297131174",
    references = "doi101111mms12911"
}

Abstract Killer whales (Orcinus orca) are highly mobile, large marine apex predators that inhabit all oceans. Despite being the most conspicuous top predator, little is known about their ecology along Patagonia, Argentina. Here, we used carbon (δ 13 C) and nitrogen (δ 15 N) isotope analysis of bone and dentine collagen from killer whales (n = 13) stranded in northern Patagonia during the period 1970–2014 to assess their trophic ecology. A model‐based clustering analysis identified three distinct groups related with three large marine ecosystems: the Patagonia (P), Subtropical (ST), and Antarctica (A) groups. Group P (n = 8) is characterized by individuals with high δ 13 C and δ 15 N values fitting within the isotopic ratios observed over the Patagonian shelf. Group ST (n = 3) is composed of individuals with high δ 13 C and low δ 15 N values, similar to those reported for conspecifics in southern Brazil. Group A (n = 2) is composed of individuals with low δ 13 C and δ 15 N values, typical from high latitude areas like sub‐Antarctic/Antarctic waters. The finding of different killer whales' isotopic groups over the Patagonian shelf suggests the existence of individuals or groups exploiting different habitats. Our results expand the limited ecological knowledge for the species while presenting the basis to infer more complex ecological hypotheses.

@article{doi101111mms13048,
    author = "Loizaga, Rocío and García, Néstor A. and Durante, Cristian Alberto and Vales, Damián G. and Crespo, Enrique A.",
    title = "Killer whales at northern Patagonia, Argentina: Evidence of different foraging groups from stable isotopes",
    year = "2023",
    journal = "Marine Mammal Science",
    abstract = "Abstract Killer whales (Orcinus orca) are highly mobile, large marine apex predators that inhabit all oceans. Despite being the most conspicuous top predator, little is known about their ecology along Patagonia, Argentina. Here, we used carbon (δ 13 C) and nitrogen (δ 15 N) isotope analysis of bone and dentine collagen from killer whales (n = 13) stranded in northern Patagonia during the period 1970–2014 to assess their trophic ecology. A model‐based clustering analysis identified three distinct groups related with three large marine ecosystems: the Patagonia (P), Subtropical (ST), and Antarctica (A) groups. Group P (n = 8) is characterized by individuals with high δ 13 C and δ 15 N values fitting within the isotopic ratios observed over the Patagonian shelf. Group ST (n = 3) is composed of individuals with high δ 13 C and low δ 15 N values, similar to those reported for conspecifics in southern Brazil. Group A (n = 2) is composed of individuals with low δ 13 C and δ 15 N values, typical from high latitude areas like sub‐Antarctic/Antarctic waters. The finding of different killer whales' isotopic groups over the Patagonian shelf suggests the existence of individuals or groups exploiting different habitats. Our results expand the limited ecological knowledge for the species while presenting the basis to infer more complex ecological hypotheses.",
    url = "https://doi.org/10.1111/mms.13048",
    doi = "10.1111/mms.13048",
    openalex = "W4385380104",
    references = "doi101111mms12911"
}

Located in the eastern tropical Pacific, the Galápagos Islands are an oceanic insular ecosystem subject to strong environmental variability driven by local and regional processes. Past research has shown that such conditions can attract and sustain at least 23 cetacean species, out of which 14 are common, including nine Delphinids, one Ziphiid, one Physeterid, and three Balaenopterids. These species occupy both coastal and oceanic habitats, most are present year-round, and a few are migratory. However, research on cetaceans in Galápagos has been sporadic and chronically underfunded and is not currently considered a priority in the research agenda for Galápagos. Based on a review of existing information and an assessment of knowledge gaps, here we identify priorities for ecological research on cetaceans in Galápagos along five topical areas: 1) spatiotemporal occurrence, 2) population assessment, 3) health assessment, 4) social ecology, and 5) trophic ecology. Addressing these knowledge gaps will also help inform actions to preserve cetacean biodiversity and to manage human activities involving or affecting cetaceans in Galápagos. Given the logistical and funding challenges of conducting cetacean research in Galápagos, we recommend optimizing data sampling and accessibility via integrated research protocols and open data repositories. We also recommend capitalizing on local citizen science activities, such as those conducted from cruise ships and whale-watching tours, which can serve as platforms of opportunity for obtaining basic data, thereby contributing to long-term data acquisition. Our proposed priorities should be assessed by Ecuadorian and Galápagos governmental institutions in broad and inclusive consultation with stakeholders and the scientific community prior to development and implementation of a research agenda. Collectively, these efforts will advance our understanding of the ecological role that marine megafauna, such as cetaceans, play in Galápagos and other oceanic islands, including maintaining large-scale connectivity and mitigating climate change.

@article{doi103389fmars20231084057,
    author = "Palacios, Daniel M. and Cantor, Maurício",
    title = "Priorities for ecological research on cetaceans in the Galápagos Islands",
    year = "2023",
    journal = "Frontiers in Marine Science",
    abstract = "Located in the eastern tropical Pacific, the Galápagos Islands are an oceanic insular ecosystem subject to strong environmental variability driven by local and regional processes. Past research has shown that such conditions can attract and sustain at least 23 cetacean species, out of which 14 are common, including nine Delphinids, one Ziphiid, one Physeterid, and three Balaenopterids. These species occupy both coastal and oceanic habitats, most are present year-round, and a few are migratory. However, research on cetaceans in Galápagos has been sporadic and chronically underfunded and is not currently considered a priority in the research agenda for Galápagos. Based on a review of existing information and an assessment of knowledge gaps, here we identify priorities for ecological research on cetaceans in Galápagos along five topical areas: 1) spatiotemporal occurrence, 2) population assessment, 3) health assessment, 4) social ecology, and 5) trophic ecology. Addressing these knowledge gaps will also help inform actions to preserve cetacean biodiversity and to manage human activities involving or affecting cetaceans in Galápagos. Given the logistical and funding challenges of conducting cetacean research in Galápagos, we recommend optimizing data sampling and accessibility via integrated research protocols and open data repositories. We also recommend capitalizing on local citizen science activities, such as those conducted from cruise ships and whale-watching tours, which can serve as platforms of opportunity for obtaining basic data, thereby contributing to long-term data acquisition. Our proposed priorities should be assessed by Ecuadorian and Galápagos governmental institutions in broad and inclusive consultation with stakeholders and the scientific community prior to development and implementation of a research agenda. Collectively, these efforts will advance our understanding of the ecological role that marine megafauna, such as cetaceans, play in Galápagos and other oceanic islands, including maintaining large-scale connectivity and mitigating climate change.",
    url = "https://doi.org/10.3389/fmars.2023.1084057",
    doi = "10.3389/fmars.2023.1084057",
    openalex = "W4320723533",
    references = "doi101111mms12911"
}

Irish and Scottish waters are important habitats for cetaceans in Europe. Yet, little data is available for the region of the Malin Shelf, north of Ireland. Despite a rich species diversity, relative cetacean abundance appears low compared to hotspots documented west of Scotland and Ireland. Whether this perceived low prevalence accurately portrays an ecological discontinuity or arises from a lack of published results and low survey effort in that transborder area remains unclear. Here, we used sighting records from a multi-disciplinary fisheries survey, the Western European Shelf Pelagic Acoustic Survey (WESPAS), to explore cetacean habitat preferences over the Malin and Hebridean shelves. Northern minke whale and common dolphin occurrence was modelled within a Bayesian Additive Regression Trees (BART) framework, against selected environmental and biological variables. No correlation was observed between cetacean presence and in-situ prey biomass. Minke whales distribution was better explained by oceanography, notably proxies for frontal activity, and primary productivity. Common dolphins similarly showed preferences for shelf waters within 5-25km of fronts, but also affinities for fine substrates. Favourable habitats identified by the models were consistent with literature around the Hebrides and shed light on potentially important areas along the Islay front and north of Donegal, so far unreported due to data deficiency. Results will contribute towards informing future monitoring, strategic management and conservation efforts in this cross-border region.

@article{doi103389fmars20231224267,
    author = "Pommier, Morgane and O’Donnell, Ciarán and Barile, Cynthia and McGill, Ross and Berrow, Simon and O’Brien, Joanne",
    title = "Exploring environmental and biological drivers of cetacean occurrence in the cross-border region of the Malin Shelf using data from a European fishery survey",
    year = "2023",
    journal = "Frontiers in Marine Science",
    abstract = "Irish and Scottish waters are important habitats for cetaceans in Europe. Yet, little data is available for the region of the Malin Shelf, north of Ireland. Despite a rich species diversity, relative cetacean abundance appears low compared to hotspots documented west of Scotland and Ireland. Whether this perceived low prevalence accurately portrays an ecological discontinuity or arises from a lack of published results and low survey effort in that transborder area remains unclear. Here, we used sighting records from a multi-disciplinary fisheries survey, the Western European Shelf Pelagic Acoustic Survey (WESPAS), to explore cetacean habitat preferences over the Malin and Hebridean shelves. Northern minke whale and common dolphin occurrence was modelled within a Bayesian Additive Regression Trees (BART) framework, against selected environmental and biological variables. No correlation was observed between cetacean presence and in-situ prey biomass. Minke whales distribution was better explained by oceanography, notably proxies for frontal activity, and primary productivity. Common dolphins similarly showed preferences for shelf waters within 5-25km of fronts, but also affinities for fine substrates. Favourable habitats identified by the models were consistent with literature around the Hebrides and shed light on potentially important areas along the Islay front and north of Donegal, so far unreported due to data deficiency. Results will contribute towards informing future monitoring, strategic management and conservation efforts in this cross-border region.",
    url = "https://doi.org/10.3389/fmars.2023.1224267",
    doi = "10.3389/fmars.2023.1224267",
    openalex = "W4388768062",
    references = "openalexw2546754148"
}

Numerous studies have demonstrated the negative effects of impoverished environments versus the positive effects of enriched environments on animals' cognitive and neural functioning. Recently, a hypothesis was raised suggesting that conditions for dolphins in zoological facilities may be inherently impoverished, and thus lead to neural and cognitive deficits. This review directly examines that hypothesis in light of the existing scientific literature relevant to dolphin welfare in zoological facilities. Specifically, it examines how dolphins are housed in modern zoological facilities, where the characteristics of such housing fall on the continuum of impoverished-to-enriched environments, and the extent to which dolphins show behavioral evidence characteristic of living in impoverished environments. The results of this analysis show that contrary to the original hypothesis, modern zoological facilities do not inherently, or even typically, house dolphins in impoverished conditions. However, it also notes that there is variation in animal welfare across different zoological facilities, and that "not impoverished" would be a particularly low bar to set as an animal welfare standard. To optimize cognitive well-being, strategies for providing additional cognitive challenges for dolphins in zoological facilities are suggested.

@article{doi103390ani13172707,
    author = "Jaakkola, Kelly",
    title = "Are Dolphins Kept in Impoverished Environments?",
    year = "2023",
    journal = "Animals",
    abstract = {Numerous studies have demonstrated the negative effects of impoverished environments versus the positive effects of enriched environments on animals' cognitive and neural functioning. Recently, a hypothesis was raised suggesting that conditions for dolphins in zoological facilities may be inherently impoverished, and thus lead to neural and cognitive deficits. This review directly examines that hypothesis in light of the existing scientific literature relevant to dolphin welfare in zoological facilities. Specifically, it examines how dolphins are housed in modern zoological facilities, where the characteristics of such housing fall on the continuum of impoverished-to-enriched environments, and the extent to which dolphins show behavioral evidence characteristic of living in impoverished environments. The results of this analysis show that contrary to the original hypothesis, modern zoological facilities do not inherently, or even typically, house dolphins in impoverished conditions. However, it also notes that there is variation in animal welfare across different zoological facilities, and that "not impoverished" would be a particularly low bar to set as an animal welfare standard. To optimize cognitive well-being, strategies for providing additional cognitive challenges for dolphins in zoological facilities are suggested.},
    url = "https://doi.org/10.3390/ani13172707",
    doi = "10.3390/ani13172707",
    openalex = "W4386168472",
    references = "crossref2005whales"
}

A vessel-based line-transect survey conducted during February 2004 along 1,018km of systematic trackline in the nearshore waters of Bangladesh resulted in 111 ‘on-effort’ cetacean sightings including: Irrawaddy dolphins, Orcaella brevirostris (n=75, mean group size=2.2); finless porpoises, Neophocaena phocaenoides (n=11, mean group size=2.6); Indo-Pacific humpback dolphins, Sousa chinensis (chinensisform; n=6, mean group size=16.2); Indo-Pacific bottlenose dolphins, Tursiops aduncus (n=3, mean group size=36.1); pantropical spotted dolphins, Stenella attenuata (n=1, best, high and low group size estimates=800, 1,100 and 600, respectively); Bryde’s whales, Balaenoptera edeni/brydei (large-form; n=1, three individuals); and unidentified small cetaceans (n=14). Cetacean distribution was closely tied to environmental gradients, with Irrawaddy dolphins and finless porpoises occurring most often in nearshore, turbid, low-salinity waters, IndoPacific humpback dolphins in slightly deeper waters where the colour turned from brown to green and Indo-Pacific bottlenose dolphins and Bryde’s whales in deep, clear, high-salinity waters of the Swatch-of-No-Ground (SoNG), a 900+m-deep submarine canyon that extends to within about 40km of the Sundarbans mangrove forest. A Generalised Additive Model of environmental and presence-absence data indicated that Irrawaddy dolphin distribution was conditionally dependent (p<0.05) on low salinity and shallow depth, which explained 36% of the variance. A distance analysis of Irrawaddy dolphin and finless porpoise sightings resulted in abundance estimates of 5,383 (CV=39.5) and 1,382 (CV=54.8%), respectively. The positive conservation implications of these abundance estimates were tempered by observations of potentially unsustainable bycatch in gillnet fisheries targeting elasmobranches and scarring on bottlenose dolphins consistent with trawl fishery interactions. The nearshore waters of Bangladesh support a taxonomically diverse and relatively abundant cetacean fauna, which can probably be explained by the wide variety of environmental gradients (river-sea and shallow-deep) available within a relatively small area and the enormous biological production driven by extreme fluvial and oceanographic processes. Priority recommendations for future research include: (1) evaluating bycatch levels and the types of fishing gears responsible for incidental kills; (2) investigating the spatial and temporal dynamics of high-density cetacean hotspots; (3) resolving the species and population identities of baleen whales and delphinids occurring in the SoNG; and (4) assessing the abundance, movement patterns and fishery interactions of Indo-Pacific bottlenose dolphins.

@article{doi1047536jcrmv10i1659,
    author = "Smith, Brian D. S and Ahmed, Be‐Nazir and Mowgli, Rubaiyat Mansur and Strindberg, Samantha",
    title = "Species occurrence and distributional ecology of nearshore cetaceans in the Bay of Bengal, Bangladesh, with abundance estimates for Irrawaddy dolphins Orcaella brevirostris and finless porpoises Neophocaena phocaenoides",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "A vessel-based line-transect survey conducted during February 2004 along 1,018km of systematic trackline in the nearshore waters of Bangladesh resulted in 111 ‘on-effort’ cetacean sightings including: Irrawaddy dolphins, Orcaella brevirostris (n=75, mean group size=2.2); finless porpoises, Neophocaena phocaenoides (n=11, mean group size=2.6); Indo-Pacific humpback dolphins, Sousa chinensis (chinensisform; n=6, mean group size=16.2); Indo-Pacific bottlenose dolphins, Tursiops aduncus (n=3, mean group size=36.1); pantropical spotted dolphins, Stenella attenuata (n=1, best, high and low group size estimates=800, 1,100 and 600, respectively); Bryde’s whales, Balaenoptera edeni/brydei (large-form; n=1, three individuals); and unidentified small cetaceans (n=14). Cetacean distribution was closely tied to environmental gradients, with Irrawaddy dolphins and finless porpoises occurring most often in nearshore, turbid, low-salinity waters, IndoPacific humpback dolphins in slightly deeper waters where the colour turned from brown to green and Indo-Pacific bottlenose dolphins and Bryde’s whales in deep, clear, high-salinity waters of the Swatch-of-No-Ground (SoNG), a 900+m-deep submarine canyon that extends to within about 40km of the Sundarbans mangrove forest. A Generalised Additive Model of environmental and presence-absence data indicated that Irrawaddy dolphin distribution was conditionally dependent (p<0.05) on low salinity and shallow depth, which explained 36\% of the variance. A distance analysis of Irrawaddy dolphin and finless porpoise sightings resulted in abundance estimates of 5,383 (CV=39.5) and 1,382 (CV=54.8\%), respectively. The positive conservation implications of these abundance estimates were tempered by observations of potentially unsustainable bycatch in gillnet fisheries targeting elasmobranches and scarring on bottlenose dolphins consistent with trawl fishery interactions. The nearshore waters of Bangladesh support a taxonomically diverse and relatively abundant cetacean fauna, which can probably be explained by the wide variety of environmental gradients (river-sea and shallow-deep) available within a relatively small area and the enormous biological production driven by extreme fluvial and oceanographic processes. Priority recommendations for future research include: (1) evaluating bycatch levels and the types of fishing gears responsible for incidental kills; (2) investigating the spatial and temporal dynamics of high-density cetacean hotspots; (3) resolving the species and population identities of baleen whales and delphinids occurring in the SoNG; and (4) assessing the abundance, movement patterns and fishery interactions of Indo-Pacific bottlenose dolphins.",
    url = "https://doi.org/10.47536/jcrm.v10i1.659",
    doi = "10.47536/jcrm.v10i1.659",
    openalex = "W4320915611",
    references = "doi1015159789882200159016"
}

Relatively little is known about the distribution of cetaceans in Indian seas due to lack of systematic surveys. For collecting data on species distribution, 35 opportunistic surveys were conducted onboard FORV Sagar Sampada between October 2003 and February 2007 in the Indian EEZ and contiguous seas. In 5,254 hours of sighting effort, a total of 473 cetacean records were made with 5,865 individuals. The occurrence of 10 species from three cetacean families was confirmed. The Indo-Pacific bottlenose dolphin was the most frequently sighted species, whereas the spinner dolphin was dominant in terms of abundance. Long-beaked common dolphins, Indo-Pacific hump-backed dolphin and sperm whales were also recorded at frequent intervals. Cetaceans were found to have a wide geographical distribution in the Indian EEZ and contiguous seas. High abundance and species richness were recorded in the Southeastern Arabian Sea and southern Sri Lankan waters. From the information collected during the present study, the platform of opportunity has proved to be a useful means for cetacean survey.

@article{doi1047536jcrmv10i3637,
    author = "Afsal, V.V. and Yousuf, K S S M and Anoop, B. K. and Kannan, P. and Rajagopalan, M. and Vivekanandan, E",
    title = "A note on cetacean distribution in the Indian EEZ and contiguous seas during 2003-07",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "Relatively little is known about the distribution of cetaceans in Indian seas due to lack of systematic surveys. For collecting data on species distribution, 35 opportunistic surveys were conducted onboard FORV Sagar Sampada between October 2003 and February 2007 in the Indian EEZ and contiguous seas. In 5,254 hours of sighting effort, a total of 473 cetacean records were made with 5,865 individuals. The occurrence of 10 species from three cetacean families was confirmed. The Indo-Pacific bottlenose dolphin was the most frequently sighted species, whereas the spinner dolphin was dominant in terms of abundance. Long-beaked common dolphins, Indo-Pacific hump-backed dolphin and sperm whales were also recorded at frequent intervals. Cetaceans were found to have a wide geographical distribution in the Indian EEZ and contiguous seas. High abundance and species richness were recorded in the Southeastern Arabian Sea and southern Sri Lankan waters. From the information collected during the present study, the platform of opportunity has proved to be a useful means for cetacean survey.",
    url = "https://doi.org/10.47536/jcrm.v10i3.637",
    doi = "10.47536/jcrm.v10i3.637",
    openalex = "W106400708",
    references = "doi1010160198025487902834, doi101017s175526720900075x, doi101111j174876921998tb00736x, doi1015159789882200173007, doi105281zenodo13245039, doi105281zenodo13520574, openalexw2344718058, openalexw3187043151, openalexw569878493, openalexw85967137"
}

The diversity of cetacean species in Indian waters is high, with 25 species recorded so far. Records of cetaceans from India during the last 200 years have provided insights into their spatiotemporal distribution, behaviour, feeding, reproduction, fishery interaction and pollution. The cetacean fauna is dominated by pantropical species, with a relatively high abundance of spinner dolphins, which is similar to other areas studied within the northern Indian Ocean. Historical records were analysed to propose an inventory of cetaceans. Cetacean diversity was highest in the Gulf of Mannar on the southeast coast of India, which with 14 species recorded from a small area can be considered a ‘hot spot’ for further research. Fishery interactions, domestic consumption, pollution and lack of quality information to inform management are the main threats for successful survival of cetaceans. The status of information regarding cetaceans in India could be classified based on this study as: six species with adequate data; five species where data is restricted to a few geographic locations; four species for which data collection is being initiated; five species with sparse data; and six species which are difficult to observe.

@article{doi1047536jcrmv12i2573,
    author = "Kumarran, R. P.",
    title = "Cetaceans and cetacean research in India",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "The diversity of cetacean species in Indian waters is high, with 25 species recorded so far. Records of cetaceans from India during the last 200 years have provided insights into their spatiotemporal distribution, behaviour, feeding, reproduction, fishery interaction and pollution. The cetacean fauna is dominated by pantropical species, with a relatively high abundance of spinner dolphins, which is similar to other areas studied within the northern Indian Ocean. Historical records were analysed to propose an inventory of cetaceans. Cetacean diversity was highest in the Gulf of Mannar on the southeast coast of India, which with 14 species recorded from a small area can be considered a ‘hot spot’ for further research. Fishery interactions, domestic consumption, pollution and lack of quality information to inform management are the main threats for successful survival of cetaceans. The status of information regarding cetaceans in India could be classified based on this study as: six species with adequate data; five species where data is restricted to a few geographic locations; four species for which data collection is being initiated; five species with sparse data; and six species which are difficult to observe.",
    url = "https://doi.org/10.47536/jcrm.v12i2.573",
    doi = "10.47536/jcrm.v12i2.573",
    openalex = "W4319593797",
    references = "doi101016s0022098102003829, doi101046j03051838200300027x, doi1016441545154220020831151eomm20co2, doi102960jv22a17, doi1047536jcrmv10i3637, doi1047536jcrmv7i2745, doi105962p203715, doi105962p226804, openalexw2344718058, openalexw3187043151, openalexw569878493, openalexw583646462"
}

The Indian Ocean Sanctuary was established in 1979 in an effort to allow exploited stocks of whales to recover from whaling and to facilitate benign research. Further information is required to establish comprehensive management and conservation measures for species within these waters. The current study took place in the offshore waters of Sri Lanka in early 2003. During three research cruises conducted between 29 March and 17 June 2003 the R/V Odyssey covered a total track line of 4,480km around the island resulting in 52 confirmed group sightings of 11 species from three cetacean families. As the tracklines were designed to locate sperm whales (Physeter macrocephalus) for tissue sampling, they accounted for the greatest number of sightings. Only two species of balaenopterids, the blue whale (Balaenoptera musculus) and the Bryde’s whale (Balaenoptera edeni), were recorded with the blue whale being the most frequently sighted species. Spinner dolphins (Stenella longirostris) were the most dominant species in terms of numbers. Some small odonotocetes such as the common bottlenose dolphin (Tursiops truncatus), striped dolphin (Stenella coeruleoalba) and Fraser’s dolphin (Lagenodelphis hosei) were observed in mixed-species groups, while one group of melon-headed whales (Peponocephala electra) was seen associating with a group of sperm whales. Risso’s dolphins (Grampus griseus) were frequently sighted throughout the research cruise, with one unusual record of a large mating group. Many sightings were made in the vicinity of the numerous submarine canyons around Sri Lanka’s coastline highlighting their potential role in enhancing productivity in the offshore waters. It is concluded that Sri Lankan offshore waters hold a rich, but little surveyed cetacean fauna that warrants further studies and implementation of conservation measures to protect these populations.

@article{doi1047536jcrmv12i2576,
    author = "de Vos, Asha and Clark, Rebecca and JOHNSON, CANCIYAL and Johnson, Genevieve and Kerr, Iain and Payne, Roger and Madsen, Peter T.",
    title = "Cetacean sightings and acoustic detections in the offshore waters of Sri Lanka: March–June 2003",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "The Indian Ocean Sanctuary was established in 1979 in an effort to allow exploited stocks of whales to recover from whaling and to facilitate benign research. Further information is required to establish comprehensive management and conservation measures for species within these waters. The current study took place in the offshore waters of Sri Lanka in early 2003. During three research cruises conducted between 29 March and 17 June 2003 the R/V Odyssey covered a total track line of 4,480km around the island resulting in 52 confirmed group sightings of 11 species from three cetacean families. As the tracklines were designed to locate sperm whales (Physeter macrocephalus) for tissue sampling, they accounted for the greatest number of sightings. Only two species of balaenopterids, the blue whale (Balaenoptera musculus) and the Bryde’s whale (Balaenoptera edeni), were recorded with the blue whale being the most frequently sighted species. Spinner dolphins (Stenella longirostris) were the most dominant species in terms of numbers. Some small odonotocetes such as the common bottlenose dolphin (Tursiops truncatus), striped dolphin (Stenella coeruleoalba) and Fraser’s dolphin (Lagenodelphis hosei) were observed in mixed-species groups, while one group of melon-headed whales (Peponocephala electra) was seen associating with a group of sperm whales. Risso’s dolphins (Grampus griseus) were frequently sighted throughout the research cruise, with one unusual record of a large mating group. Many sightings were made in the vicinity of the numerous submarine canyons around Sri Lanka’s coastline highlighting their potential role in enhancing productivity in the offshore waters. It is concluded that Sri Lankan offshore waters hold a rich, but little surveyed cetacean fauna that warrants further studies and implementation of conservation measures to protect these populations.",
    url = "https://doi.org/10.47536/jcrm.v12i2.576",
    doi = "10.47536/jcrm.v12i2.576",
    openalex = "W2188059045",
    references = "doi1047536jcrmv10i3637"
}

There is a distinct population of blue whales, Balaenoptera musculus, in the northern Indian Ocean. The taxonomic status of these animals has long been uncertain, with debate over whether this population represents a distinct subspecies, and if so which name should apply. They have most frequently been assigned to B. musculus brevicauda, but are currently considered to be B. m. indica. The movements of these blue whales within the northern Indian Ocean are poorly understood. This paper reviews catches (n = 1,288), sightings (n = 448, with a minimum of 783 animals), strandings (n = 64) and acoustic detections (n = 6 locations); uses ocean colour data to estimate seasonality of primary productivity in different areas of the northern Indian Ocean; and develops a migration hypothesis. It is suggested that most of these whales feed in the Arabian Sea off the coasts of Somalia and the Arabian peninsula during the period of intense upwelling associated with the southwest monsoon (from about May to October). At the same time some blue whales also feed in the area of upwelling off the southwest coast of India and west coast of Sri Lanka. When the southwest monsoon dies down in about October–November these upwellings cease. The blue whales then disperse more widely to eke out the leaner months of the northeast monsoon (during about December to March) in other localised areas with seasonally high productivity. These include the east coast of Sri Lanka, the waters west of the Maldives, the vicinity of the Indus Canyon (at least historically), and some parts of the southern Indian Ocean. The data are consistent with the hypothesis that at least some of the blue whales that feed off the east coast of Sri Lanka in the northeast monsoon also feed in the Arabian Sea during the southwest monsoon. These whales appear to migrate eastwards past the north of Maldives and south of Sri Lanka in about December–January, returning westwards in about April–May

@article{doi1047536jcrmv12i2578,
    author = "Andersen, R. Charles and Branch, Trevor A. and ALAGIYAWADU, ANOMA I. and Baldwin, R.M. and Marsac, Francis",
    title = "Seasonal distribution, movements and taxonomic status of blue whales (Balaenoptera musculus) in the northern Indian Ocean",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "There is a distinct population of blue whales, Balaenoptera musculus, in the northern Indian Ocean. The taxonomic status of these animals has long been uncertain, with debate over whether this population represents a distinct subspecies, and if so which name should apply. They have most frequently been assigned to B. musculus brevicauda, but are currently considered to be B. m. indica. The movements of these blue whales within the northern Indian Ocean are poorly understood. This paper reviews catches (n = 1,288), sightings (n = 448, with a minimum of 783 animals), strandings (n = 64) and acoustic detections (n = 6 locations); uses ocean colour data to estimate seasonality of primary productivity in different areas of the northern Indian Ocean; and develops a migration hypothesis. It is suggested that most of these whales feed in the Arabian Sea off the coasts of Somalia and the Arabian peninsula during the period of intense upwelling associated with the southwest monsoon (from about May to October). At the same time some blue whales also feed in the area of upwelling off the southwest coast of India and west coast of Sri Lanka. When the southwest monsoon dies down in about October–November these upwellings cease. The blue whales then disperse more widely to eke out the leaner months of the northeast monsoon (during about December to March) in other localised areas with seasonally high productivity. These include the east coast of Sri Lanka, the waters west of the Maldives, the vicinity of the Indus Canyon (at least historically), and some parts of the southern Indian Ocean. The data are consistent with the hypothesis that at least some of the blue whales that feed off the east coast of Sri Lanka in the northeast monsoon also feed in the Arabian Sea during the southwest monsoon. These whales appear to migrate eastwards past the north of Maldives and south of Sri Lanka in about December–January, returning westwards in about April–May",
    url = "https://doi.org/10.47536/jcrm.v12i2.578",
    doi = "10.47536/jcrm.v12i2.578",
    openalex = "W888864581",
    references = "doi101006jaer19931063, doi10100797836426546883, doi101016b9780124555211x50001, doi101016s0079661101000830, doi101016s0079661102000241, doi10102998eo00443, doi10102998jc02160, doi101111j174876922001tb00980x, doi1047536jcrmv10i3637, openalexw2344718058, openalexw567256500, openalexw583646462"
}

This paper reports the findings of a project (Cetacean Conservation Pakistan) launched in 2004 with a view to: (a) undertaking quantitative surveys to determine the variety and abundance of species present; (b) working with local fisher communities to collate local knowledge and promote public awareness; and (c) promoting a marine cetacean conservation strategy and measures. Boat-based surveys for live animals and shore surveys for beachcast specimens have confirmed the presence of twelve species of whale and dolphin. Among these bottlenose dolphins (Tursiops sp.) occur both inshore along the coasts of Sindh and Balochistan, and offshore in parts of Balochistan; these two populations possibly representing different sub-species. Indo-Pacific humpback dolphins (Sousa chinensis) are common inshore around the mouth of the Indus Delta and in large sheltered bays in Balochistan, where finless porpoise (Neophocaena phocaenoides) also occur. Spinner dolphins (Stenella longirostris) were observed in very large schools (up to 2,000) around the shelf edge in eastern Balochistan, as were Risso’s dolphins (Grampus griseus) in smaller numbers. Common dolphins (Delphinus capensis) were recorded even further offshore. There were two sightings of humpback whales (Megaptera novaeangliae), and one of a killer whale (Orcinus orca). Bryde’s whales (Balaenoptera edeni), sperm whales (Physeter macrocephalus) and Cuvier’s beaked whales (Ziphius cavirostris) were recorded only during beach surveys, while skeletal remains in institutions also supported the occurrence of blue whales (Balaenoptera musculus). Work with local fisher communities supported this picture of species distribution and provided information on threats to local cetaceans. These are principally occasional entanglement in fishing gear and opportunistic exploitation for use as food, as bait, as medicine or for other purposes. The project incorporated policy development and the preparation of a marine cetacean biodiversity action plan that included the listing of species in provincial conservation legislation, the designation of a marine protected area in Balochistan, the establishment of a national whale and dolphin conservation society, and trials of whale and dolphin watching as a means of raising public awareness and providing alternative economic value.

@article{doi1047536jcrmv12i2581,
    author = "Gore, Mauvis and Kiani, Muhammad Shoaib and Ahmad, Ejaz and Hussain, Babar and Ormond, Rupert and Siddiqui, J. and Waqas, Umer and Culloch, Ross",
    title = "Occurrence of whales and dolphins in Pakistan with reference to fishers’ knowledge and impacts",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "This paper reports the findings of a project (Cetacean Conservation Pakistan) launched in 2004 with a view to: (a) undertaking quantitative surveys to determine the variety and abundance of species present; (b) working with local fisher communities to collate local knowledge and promote public awareness; and (c) promoting a marine cetacean conservation strategy and measures. Boat-based surveys for live animals and shore surveys for beachcast specimens have confirmed the presence of twelve species of whale and dolphin. Among these bottlenose dolphins (Tursiops sp.) occur both inshore along the coasts of Sindh and Balochistan, and offshore in parts of Balochistan; these two populations possibly representing different sub-species. Indo-Pacific humpback dolphins (Sousa chinensis) are common inshore around the mouth of the Indus Delta and in large sheltered bays in Balochistan, where finless porpoise (Neophocaena phocaenoides) also occur. Spinner dolphins (Stenella longirostris) were observed in very large schools (up to 2,000) around the shelf edge in eastern Balochistan, as were Risso’s dolphins (Grampus griseus) in smaller numbers. Common dolphins (Delphinus capensis) were recorded even further offshore. There were two sightings of humpback whales (Megaptera novaeangliae), and one of a killer whale (Orcinus orca). Bryde’s whales (Balaenoptera edeni), sperm whales (Physeter macrocephalus) and Cuvier’s beaked whales (Ziphius cavirostris) were recorded only during beach surveys, while skeletal remains in institutions also supported the occurrence of blue whales (Balaenoptera musculus). Work with local fisher communities supported this picture of species distribution and provided information on threats to local cetaceans. These are principally occasional entanglement in fishing gear and opportunistic exploitation for use as food, as bait, as medicine or for other purposes. The project incorporated policy development and the preparation of a marine cetacean biodiversity action plan that included the listing of species in provincial conservation legislation, the designation of a marine protected area in Balochistan, the establishment of a national whale and dolphin conservation society, and trials of whale and dolphin watching as a means of raising public awareness and providing alternative economic value.",
    url = "https://doi.org/10.47536/jcrm.v12i2.581",
    doi = "10.47536/jcrm.v12i2.581",
    openalex = "W2617921979",
    references = "doi1047536jcrmv10i3637"
}

Cetaceans observed in Maldivian waters were recorded during the period August 1990 to June 2002, from both vessels-of-opportunity and dedicated cetacean-watching cruises. A total of 1,829 cetacean sightings were recorded during 535 days at sea (equivalent to 261 standardised days). There were 83 multispecies sightings, plus a further 58 sightings without associated effort data and 129 strandings were recorded by the author and others, making a total of 2,108 cetacean records. In all, 20 different species were positively identified from sightings. Spinner dolphins were the most abundant species seen, accounting for 35% of sightings and 53% of numbers. This species showed a clear diurnal pattern of behaviour, with many schools entering the atolls in the early morning, and leaving in the late afternoon. Spinner dolphins regularly occurred with pantropical spotted dolphins and both species associated with yellowfin tuna. Bryde’s whales also associated with yellowfin tuna and appeared to be most common in Maldivian waters during El Niño Southern Oscillation events. Blue whales were only recorded during November to April. Dwarf sperm whales were especially difficult to locate in rough weather but relatively common, making up one sixth of all sightings in flat-calm conditions. Melon-headed whales were particularly common in the south of the Maldives, but rare in the centre and north. Other species recorded were humpback whale, sperm whale, rough-toothed dolphin, Risso’s dolphin, bottlenose dolphin, striped dolphin, Fraser’s dolphin, pygmy killer whale, false killer whale, killer whale, short-finned pilot whale, Blainville’s beaked whale, Longman’s beaked whale and Cuvier’s beaked whale.

@article{doi1047536jcrmv7i2745,
    author = "Anderson, Robert C.",
    title = "Observations of cetaceans in the Maldives, 1990-2002",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "Cetaceans observed in Maldivian waters were recorded during the period August 1990 to June 2002, from both vessels-of-opportunity and dedicated cetacean-watching cruises. A total of 1,829 cetacean sightings were recorded during 535 days at sea (equivalent to 261 standardised days). There were 83 multispecies sightings, plus a further 58 sightings without associated effort data and 129 strandings were recorded by the author and others, making a total of 2,108 cetacean records. In all, 20 different species were positively identified from sightings. Spinner dolphins were the most abundant species seen, accounting for 35\% of sightings and 53\% of numbers. This species showed a clear diurnal pattern of behaviour, with many schools entering the atolls in the early morning, and leaving in the late afternoon. Spinner dolphins regularly occurred with pantropical spotted dolphins and both species associated with yellowfin tuna. Bryde’s whales also associated with yellowfin tuna and appeared to be most common in Maldivian waters during El Niño Southern Oscillation events. Blue whales were only recorded during November to April. Dwarf sperm whales were especially difficult to locate in rough weather but relatively common, making up one sixth of all sightings in flat-calm conditions. Melon-headed whales were particularly common in the south of the Maldives, but rare in the centre and north. Other species recorded were humpback whale, sperm whale, rough-toothed dolphin, Risso’s dolphin, bottlenose dolphin, striped dolphin, Fraser’s dolphin, pygmy killer whale, false killer whale, killer whale, short-finned pilot whale, Blainville’s beaked whale, Longman’s beaked whale and Cuvier’s beaked whale.",
    url = "https://doi.org/10.47536/jcrm.v7i2.745",
    doi = "10.47536/jcrm.v7i2.745",
    openalex = "W4324382672",
    references = "doi105962p358359"
}

Fishery-cetacean interactions, including those with longline gear, give rise to economic, ecological and social concerns. This paper reviews problems resulting from cetacean-longline interactions, considers potential strategies to reduce interactions and identifies research priorities and approaches. Depredation by cetaceans (removal and damage of hooked fish and bait from fishing gear) and damage and loss of fishing gear create economic problems; however, the magnitude of this problem is poorly understood. There is also insufficient information to determine whether there are population-level effects resulting from injury and mortality of cetaceans (from incidental entanglement and hooking and from deliberate actions to discourage depredation). Fishery-cetacean interactions may also: change cetacean foraging behaviour and distribution; increase fishing effort to make up for fish taken from gear by cetaceans; and create errors in fish stock assessments that do not account for cetacean depredation. Negative public perceptions of longline fishing can result from news of incidental and deliberate injury and mortality of cetaceans associated with longlining. Information on how to reduce cetacean interactions with longline gear is also limited, as is the understanding of the mechanisms responsible for them. Strategies already employed in some fleets include refraining from setting or cutting sets short when problematic species of cetaceans are observed and fleet coordination of daily fishing times and positions. Many fishermen perceive depredation as an inevitable part of fishing. This paper discusses a number of other possible cetacean avoidance strategies that warrant consideration, including: (1) fleet communication to enable vessels to avoid temporally and spatially unpredictable and sporadic hotspots of aggregations of cetaceans; (2) underwater acoustic masking devices to conceal the sound of the vessel, gear, and setting and hauling activities; (3) quieter vessels to reduce cetaceans’ ability to target longline vessels; (4) encasement of caught fish to reduce cetacean access to or interest in the catch; (5) use of bait or gear with an unpleasant smell or taste to reduce the attractiveness of gear, bait and catch to cetaceans; (6) use of pre-recorded fishing vessel sounds played from stations throughout a fleet’s fishing grounds to distract cetaceans from actual fishing vessels; (7) use of acoustic devices to mask returning cetacean echolocation signals; and (8) use of tethered sonobuoys to track cetaceans and enable fleet avoidance. Vessels with relatively low cetacean interaction rates should be examined for design and operational differences from vessels with high interaction rates, possibly allowing identification of effective avoidance methods. There is a need for experimentation in individual longline fisheries over several seasons to assess fisheryspecific efficacy and commercial viability of cetacean avoidance strategies. This is necessary as different cetacean species likely respond differently to an avoidance method and cetaceans may habituate to an avoidance strategy, especially in fisheries interacting with resident cetaceans.

@article{doi1047536jcrmv8i2717,
    author = "Gilman, Eric and Brothers, Nigel and McPherson, Geof and Dalzell, P.",
    title = "A review of cetacean interactions with longline gear",
    year = "2023",
    journal = "˜The œjournal of cetacean research and management. Special issue",
    abstract = "Fishery-cetacean interactions, including those with longline gear, give rise to economic, ecological and social concerns. This paper reviews problems resulting from cetacean-longline interactions, considers potential strategies to reduce interactions and identifies research priorities and approaches. Depredation by cetaceans (removal and damage of hooked fish and bait from fishing gear) and damage and loss of fishing gear create economic problems; however, the magnitude of this problem is poorly understood. There is also insufficient information to determine whether there are population-level effects resulting from injury and mortality of cetaceans (from incidental entanglement and hooking and from deliberate actions to discourage depredation). Fishery-cetacean interactions may also: change cetacean foraging behaviour and distribution; increase fishing effort to make up for fish taken from gear by cetaceans; and create errors in fish stock assessments that do not account for cetacean depredation. Negative public perceptions of longline fishing can result from news of incidental and deliberate injury and mortality of cetaceans associated with longlining. Information on how to reduce cetacean interactions with longline gear is also limited, as is the understanding of the mechanisms responsible for them. Strategies already employed in some fleets include refraining from setting or cutting sets short when problematic species of cetaceans are observed and fleet coordination of daily fishing times and positions. Many fishermen perceive depredation as an inevitable part of fishing. This paper discusses a number of other possible cetacean avoidance strategies that warrant consideration, including: (1) fleet communication to enable vessels to avoid temporally and spatially unpredictable and sporadic hotspots of aggregations of cetaceans; (2) underwater acoustic masking devices to conceal the sound of the vessel, gear, and setting and hauling activities; (3) quieter vessels to reduce cetaceans’ ability to target longline vessels; (4) encasement of caught fish to reduce cetacean access to or interest in the catch; (5) use of bait or gear with an unpleasant smell or taste to reduce the attractiveness of gear, bait and catch to cetaceans; (6) use of pre-recorded fishing vessel sounds played from stations throughout a fleet’s fishing grounds to distract cetaceans from actual fishing vessels; (7) use of acoustic devices to mask returning cetacean echolocation signals; and (8) use of tethered sonobuoys to track cetaceans and enable fleet avoidance. Vessels with relatively low cetacean interaction rates should be examined for design and operational differences from vessels with high interaction rates, possibly allowing identification of effective avoidance methods. There is a need for experimentation in individual longline fisheries over several seasons to assess fisheryspecific efficacy and commercial viability of cetacean avoidance strategies. This is necessary as different cetacean species likely respond differently to an avoidance method and cetaceans may habituate to an avoidance strategy, especially in fisheries interacting with resident cetaceans.",
    url = "https://doi.org/10.47536/jcrm.v8i2.717",
    doi = "10.47536/jcrm.v8i2.717",
    openalex = "W4323543733",
    references = "doi1010160967065396842815"
}

Whales (cetaceans, including dolphins and porpoises) are superbly adapted to life in water, but retain vestiges of their terrestrial ancestry, particularly the need to breathe air. Their respiratory tract exhibits many differences from their closest relatives, the terrestrial artiodactyls (even toed ungulates). In this review, we describe the anatomy of cetacean respiratory adaptions. These include protective features (e.g., preventing water incursions during breathing or swallowing, mitigating effects of pressure changes during diving/ascent) and unique functions (e.g., underwater sound production, regulating gas exchange during the dive cycle).

@article{doi101002ar25597,
    author = "Reidenberg, Joy S. and Laitman, Jeffrey T.",
    title = "Review of respiratory anatomy adaptations in whales",
    year = "2024",
    journal = "The Anatomical Record",
    abstract = "Whales (cetaceans, including dolphins and porpoises) are superbly adapted to life in water, but retain vestiges of their terrestrial ancestry, particularly the need to breathe air. Their respiratory tract exhibits many differences from their closest relatives, the terrestrial artiodactyls (even toed ungulates). In this review, we describe the anatomy of cetacean respiratory adaptions. These include protective features (e.g., preventing water incursions during breathing or swallowing, mitigating effects of pressure changes during diving/ascent) and unique functions (e.g., underwater sound production, regulating gas exchange during the dive cycle).",
    url = "https://doi.org/10.1002/ar.25597",
    doi = "10.1002/ar.25597",
    openalex = "W4404007822"
}

Introduction The oceanic waters around the Azores host a high diversity of cetaceans, with 28 species of toothed and baleen whales present year-round or seasonally. This high cetacean biodiversity likely plays an important role in the structure, functioning and productivity of the ecosystem, and may increase trophic redundancy, thus contributing to food web resilience to disturbances. Methods Here we used stable isotope (δ 13 C and δ 15 N) analysis to characterize trophic niches, assess niche overlap, describe the trophic structure and discuss potential redundancy in the cetacean community. Using 407 samples from 12 species, we estimated Standard Ellipse Areas and overlaps between species and used a hierarchical clustering analysis to identify trophic guilds. Results and discussion δ 13 C and δ 15 N values ranged from -20.53 to -15.46‰ and from 7.78 to 14.41‰ respectively, suggesting the use of diverse habitats and resources among cetacean species. Clustering analysis revealed that species were grouped into four trophic guilds, segregated mainly by trophic position (TP): a low-TP guild with three zooplanktivore baleen whales, a mid-TP guild with micronektivores, a high-TP guild with micronekton and nekton consumers, and a cluster with only Pseudorca crassidens. There was significant isotopic niche overlap between one pair of species within each guild, indicating some potential for trophic redundancy in the community. Yet, these pairs also showed some form of spatial or temporal partitioning, suggesting that mechanisms promoting species coexistence could play a key role in structuring the cetacean community in the region and in its ecological role.

@article{doi103389fmars20241283357,
    author = "Lebon, Myriam and Colaço, Ana and Prieto, Rui and Cascão, Irma and Oliveira, Cláudia and Tobeña, Marta and Planque, Yann and Spitz, Jérôme and Silva, Mónica A.",
    title = "Isotopic niches reveal the trophic structure of the cetacean community in the oceanic waters around the Azores",
    year = "2024",
    journal = "Frontiers in Marine Science",
    abstract = "Introduction The oceanic waters around the Azores host a high diversity of cetaceans, with 28 species of toothed and baleen whales present year-round or seasonally. This high cetacean biodiversity likely plays an important role in the structure, functioning and productivity of the ecosystem, and may increase trophic redundancy, thus contributing to food web resilience to disturbances. Methods Here we used stable isotope (δ 13 C and δ 15 N) analysis to characterize trophic niches, assess niche overlap, describe the trophic structure and discuss potential redundancy in the cetacean community. Using 407 samples from 12 species, we estimated Standard Ellipse Areas and overlaps between species and used a hierarchical clustering analysis to identify trophic guilds. Results and discussion δ 13 C and δ 15 N values ranged from -20.53 to -15.46‰ and from 7.78 to 14.41‰ respectively, suggesting the use of diverse habitats and resources among cetacean species. Clustering analysis revealed that species were grouped into four trophic guilds, segregated mainly by trophic position (TP): a low-TP guild with three zooplanktivore baleen whales, a mid-TP guild with micronektivores, a high-TP guild with micronekton and nekton consumers, and a cluster with only Pseudorca crassidens. There was significant isotopic niche overlap between one pair of species within each guild, indicating some potential for trophic redundancy in the community. Yet, these pairs also showed some form of spatial or temporal partitioning, suggesting that mechanisms promoting species coexistence could play a key role in structuring the cetacean community in the region and in its ecological role.",
    url = "https://doi.org/10.3389/fmars.2024.1283357",
    doi = "10.3389/fmars.2024.1283357",
    openalex = "W4396619859",
    references = "doi101016jjembe201511001"
}

, its hierarchical structure allows for detailed assessments from overall welfare down to specific indicators. Through combining 37 animal-based and 12 resource-based indicators that are evaluated based on a two- or three-level scoring, the protocol offers a detailed evaluation of individual dolphins. This approach allows for regular internal monitoring and targeted welfare management, enabling caretakers to address specific welfare concerns effectively.

@article{doi103390ani14050701,
    author = "Baumgartner, Katrin and Hüttner, Tim and Clegg, Isabella L. K. and Hartmann, Manuel Garcia and García‐Párraga, Daniel and Manteca, Xavier and Mercera, Birgitta and Monreal‐Pawlowsky, Tania and Pilenga, Cristina and Ternes, Kerstin and Talló-Parra, Oriol and Vaicekauskaite, Ruta and von Fersen, Lorenzo and Yon, Lisa and Delfour, Fabienne",
    title = "Dolphin-WET—Development of a Welfare Evaluation Tool for Bottlenose Dolphins (Tursiops truncatus) under Human Care",
    year = "2024",
    journal = "Animals",
    abstract = ", its hierarchical structure allows for detailed assessments from overall welfare down to specific indicators. Through combining 37 animal-based and 12 resource-based indicators that are evaluated based on a two- or three-level scoring, the protocol offers a detailed evaluation of individual dolphins. This approach allows for regular internal monitoring and targeted welfare management, enabling caretakers to address specific welfare concerns effectively.",
    url = "https://doi.org/10.3390/ani14050701",
    doi = "10.3390/ani14050701",
    openalex = "W4392096263",
    references = "crossref2005whales"
}

Citation: 'cetaceans' in the IUPAC Compendium of Chemical Terminology, 5th ed.; International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14518 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms. Requests for commercial usage of the compendium should be directed to IUPAC.

@misc{crossref2025cetaceans,
    title = "cetaceans",
    year = "2025",
    booktitle = "The IUPAC Compendium of Chemical Terminology",
    abstract = "Citation: 'cetaceans' in the IUPAC Compendium of Chemical Terminology, 5th ed.; International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14518 • License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International for individual terms. Requests for commercial usage of the compendium should be directed to IUPAC.",
    url = "https://doi.org/10.1351/goldbook.14518",
    doi = "10.1351/goldbook.14518"
}

Understanding the foraging preference of cetaceans is crucial for assessing their role as apex predators and indicators of marine ecosystem health. Using stable isotope analysis, we investigated trophic niche differentiation and foraging plasticity in 141 long-finned pilot whales (Globicephala melas edwardii) that stranded along the Tasmanian coast at three locations (Marion Bay, King Island, and Maria Island). Stranding location accounted for most of the variability in skin isotopic values (δ 13 C: - 17.9 ± 0.2 ‰ to –16.9 ± 0.2 ‰, Principal Coordinate 1 = 89%), likely reflecting differences in foraging habitats. In addition, isotopic niche overlap ranged from minimal (0-10% between Marion Bay and Maria Island) to moderate (between Marion Bay and King Island, and King Island and Maria Island). While sex related differences in isotopic niche space were minimal overall, there was some variability in the core niche space between males and females at Maria Island. Dietary proportions from our mixing model support a predominantly cephalopod diet for pilot whales in Tasmanian waters (91%, CI: 63-90%), with greater contributions from offshore dietary sources (68%, CI: 25-95%). The dietary variability across the three strandings highlights the foraging plasticity of pilot whales, which despite their preferences for a wide range of oceanic cephalopods, can adopt a more generalist feeding strategy when necessary. These findings provide valuable insights into the ecological role and adaptability of pilot whales in Tasmanian waters, highlighting the importance of monitoring apex predators to inform conservation and ecosystem management strategies in dynamic marine ecosystems.

@article{doi103389fmars20251520905,
    author = "Jackson, Christine H. and Gales, Rosemary and Cherel, Y and Jackson, George D. and Virtue, Patti",
    title = "Trophic niche differentiation and foraging plasticity of long-finned pilot whales (Globicephala melas edwardii) in Tasmanian waters: insights from isotopic analysis",
    year = "2025",
    journal = "Frontiers in Marine Science",
    abstract = "Understanding the foraging preference of cetaceans is crucial for assessing their role as apex predators and indicators of marine ecosystem health. Using stable isotope analysis, we investigated trophic niche differentiation and foraging plasticity in 141 long-finned pilot whales (Globicephala melas edwardii) that stranded along the Tasmanian coast at three locations (Marion Bay, King Island, and Maria Island). Stranding location accounted for most of the variability in skin isotopic values (δ 13 C: - 17.9 ± 0.2 ‰ to –16.9 ± 0.2 ‰, Principal Coordinate 1 = 89\%), likely reflecting differences in foraging habitats. In addition, isotopic niche overlap ranged from minimal (0-10\% between Marion Bay and Maria Island) to moderate (between Marion Bay and King Island, and King Island and Maria Island). While sex related differences in isotopic niche space were minimal overall, there was some variability in the core niche space between males and females at Maria Island. Dietary proportions from our mixing model support a predominantly cephalopod diet for pilot whales in Tasmanian waters (91\%, CI: 63-90\%), with greater contributions from offshore dietary sources (68\%, CI: 25-95\%). The dietary variability across the three strandings highlights the foraging plasticity of pilot whales, which despite their preferences for a wide range of oceanic cephalopods, can adopt a more generalist feeding strategy when necessary. These findings provide valuable insights into the ecological role and adaptability of pilot whales in Tasmanian waters, highlighting the importance of monitoring apex predators to inform conservation and ecosystem management strategies in dynamic marine ecosystems.",
    url = "https://doi.org/10.3389/fmars.2025.1520905",
    doi = "10.3389/fmars.2025.1520905",
    openalex = "W4407170428",
    references = "doi101111mms12911"
}

) using AlphaLISA assays. Subsequently, weekly ECC and EOC levels were measured over an extended period in five managed dolphins and analyzed alongside aggregated environmental and welfare-related variables, using various time lags to account for delays between physiological activity and hormone deposition in the epidermis. ECC was negatively associated with mild weight loss and diazepam administration, exhibiting seasonal variability. In contrast, EOC was negatively associated with negative welfare indicators and COVID-19 park closures but positively associated with diazepam administration and peak visitor seasons, also showing seasonal variability. However, the interpretation of EOC remains complex due to a limited understanding of the cetacean oxytocin system and its dual role in positive and negative affective states. Overall, ECC and EOC show promise as non-invasive biomarkers for monitoring long-term welfare changes in cetaceans, although further research is necessary to validate these biomarkers across broader populations and contexts and to clarify their temporal dynamics in the epidermis.

@article{doi103390ani15172628,
    author = "Agustí, Clara and Talló-Parra, Oriol and Tejero-Caballo, Enrique and García‐Párraga, Daniel and López-Arjona, Marina and Álvaro‐Álvarez, Teresa and Joaquín-Cerón, José and Manteca, Xavier",
    title = "Tracking Epidermal Cortisol and Oxytocin in Managed Bottlenose Dolphins as Potential Non-Invasive Physiological Welfare Indicators",
    year = "2025",
    journal = "Animals",
    abstract = ") using AlphaLISA assays. Subsequently, weekly ECC and EOC levels were measured over an extended period in five managed dolphins and analyzed alongside aggregated environmental and welfare-related variables, using various time lags to account for delays between physiological activity and hormone deposition in the epidermis. ECC was negatively associated with mild weight loss and diazepam administration, exhibiting seasonal variability. In contrast, EOC was negatively associated with negative welfare indicators and COVID-19 park closures but positively associated with diazepam administration and peak visitor seasons, also showing seasonal variability. However, the interpretation of EOC remains complex due to a limited understanding of the cetacean oxytocin system and its dual role in positive and negative affective states. Overall, ECC and EOC show promise as non-invasive biomarkers for monitoring long-term welfare changes in cetaceans, although further research is necessary to validate these biomarkers across broader populations and contexts and to clarify their temporal dynamics in the epidermis.",
    url = "https://doi.org/10.3390/ani15172628",
    doi = "10.3390/ani15172628",
    openalex = "W4414063133",
    references = "crossref2005whales"
}

Growing public concern regarding cetacean welfare has emphasized the need for developing robust, science-based tools for welfare assessment applicable across diverse species and settings. Within this context, in a broader effort to advance the validation of novel physiological indicators for monitoring cetacean welfare, this study optimized a non-invasive epidermal sampling method in killer whales (Orcinus orca; N = 5) and validated AlphaLISA immunoassays for quantifying epidermal cortisol (ECC) and oxytocin (EOC) concentrations. Analysis of body location as a potential confounding factor revealed notable intra-individual variability and lateral asymmetry in hormone concentrations, highlighting the importance of standardized sampling procedures. Significant associations emerged between both hormones and negative welfare indicators, while EOC was also linked to positive behavioral engagement and body weight variation. When considered alongside previous findings, ECC may represent a reliable and feasible biomarker for assessing retrospective, intermediate-term welfare changes in killer whales, particularly when embedded within a broader, multifactorial framework that integrates complementary indicators. By contrast, EOC remains less reliable at this stage, largely due to the limited understanding of the oxytocinergic system and its involvement in both positive and negative affective states. Future research involving larger populations, detailed welfare assessments, and improved understanding of epidermal hormone incorporation dynamics will enhance the practical utility of ECC and EOC as welfare biomarkers in cetaceans.

@article{doi101016jcbpa2026111993,
    author = "Agustí, Clara and Manteca, Xavier and Almunia, Javier and López-Arjona, Marina and Cerón, José Joaquín and Tejero, Enrique Veganzones and Câmara, Nakita and Guix, Laia and Talló-Parra, Oriol",
    title = "Tracking epidermal cortisol and oxytocin in managed killer whales as potential non-invasive physiological welfare indicators",
    year = "2026",
    journal = "Comparative Biochemistry and Physiology Part A Molecular \& Integrative Physiology",
    abstract = "Growing public concern regarding cetacean welfare has emphasized the need for developing robust, science-based tools for welfare assessment applicable across diverse species and settings. Within this context, in a broader effort to advance the validation of novel physiological indicators for monitoring cetacean welfare, this study optimized a non-invasive epidermal sampling method in killer whales (Orcinus orca; N = 5) and validated AlphaLISA immunoassays for quantifying epidermal cortisol (ECC) and oxytocin (EOC) concentrations. Analysis of body location as a potential confounding factor revealed notable intra-individual variability and lateral asymmetry in hormone concentrations, highlighting the importance of standardized sampling procedures. Significant associations emerged between both hormones and negative welfare indicators, while EOC was also linked to positive behavioral engagement and body weight variation. When considered alongside previous findings, ECC may represent a reliable and feasible biomarker for assessing retrospective, intermediate-term welfare changes in killer whales, particularly when embedded within a broader, multifactorial framework that integrates complementary indicators. By contrast, EOC remains less reliable at this stage, largely due to the limited understanding of the oxytocinergic system and its involvement in both positive and negative affective states. Future research involving larger populations, detailed welfare assessments, and improved understanding of epidermal hormone incorporation dynamics will enhance the practical utility of ECC and EOC as welfare biomarkers in cetaceans.",
    url = "https://doi.org/10.1016/j.cbpa.2026.111993",
    doi = "10.1016/j.cbpa.2026.111993",
    openalex = "W7135022670",
    references = "crossref2005whales"
}

Cetaceans (whales, porpoises and dolphins) play critical roles in marine ecosystems, but many populations are declining and are vulnerable to anthropogenic disturbance. Understanding the impacts of disturbance on the physiology and health of cetacean populations and developing robust methods of assessing them are critical for their conservation. Many current approaches for studying stress in cetaceans do not address the downstream impacts of stress hormones and contaminants, which mediate their effects by altering gene activity in target tissues. The latter can be examined by transcriptome sequencing, which can rapidly produce species- and tissue-specific global gene expression profiles that can be correlated with hormone and contaminant levels to identify markers of stress and pollutant exposure. However, transcriptome studies of cetacean blubber have been limited by the high lipid and structural fibre content of this tissue, which typically yields low-quality RNA that is not suitable for sequencing. In this study, we conducted a comprehensive comparison of tissue handling and RNA extraction methods for transcriptome studies of blubber collected from free-ranging cetaceans under field conditions. We subsampled blubber biopsies obtained from wild bottlenose dolphins during routine health assessments and compared the effect of sample preservation, tissue homogenization and choice of nucleic acid extraction kit on RNA yield and integrity. We found that flash-freezing blubber upon collection, homogenization using cryogenic milling followed by bead beating and RNA extraction using a phenol-guanidine-chloroform and silica spin column kit designed for fatty and fibrous tissues significantly improve RNA quality. Using the pipeline that we developed, we show that it is possible to obtain large yields of intact RNA across the full depth of dolphin blubber with integrity values that exceed those reported thus far (up to 8.3) and that are suitable for stress biomarker discovery by RNA sequencing, facilitating health assessments of wild cetaceans sampled by remote biopsy.

@article{doi101093conphyscoag029,
    author = "Boateng, Kelvin K A and Allen, Robyn F and Wells, Randall S and Kellar, Nicholas M and Khudyakov, Jane I",
    title = "Optimized methods for obtaining sequencing-quality RNA from blubber of free-ranging cetaceans collected under field conditions.",
    year = "2026",
    journal = "Conservation physiology",
    abstract = "Cetaceans (whales, porpoises and dolphins) play critical roles in marine ecosystems, but many populations are declining and are vulnerable to anthropogenic disturbance. Understanding the impacts of disturbance on the physiology and health of cetacean populations and developing robust methods of assessing them are critical for their conservation. Many current approaches for studying stress in cetaceans do not address the downstream impacts of stress hormones and contaminants, which mediate their effects by altering gene activity in target tissues. The latter can be examined by transcriptome sequencing, which can rapidly produce species- and tissue-specific global gene expression profiles that can be correlated with hormone and contaminant levels to identify markers of stress and pollutant exposure. However, transcriptome studies of cetacean blubber have been limited by the high lipid and structural fibre content of this tissue, which typically yields low-quality RNA that is not suitable for sequencing. In this study, we conducted a comprehensive comparison of tissue handling and RNA extraction methods for transcriptome studies of blubber collected from free-ranging cetaceans under field conditions. We subsampled blubber biopsies obtained from wild bottlenose dolphins during routine health assessments and compared the effect of sample preservation, tissue homogenization and choice of nucleic acid extraction kit on RNA yield and integrity. We found that flash-freezing blubber upon collection, homogenization using cryogenic milling followed by bead beating and RNA extraction using a phenol-guanidine-chloroform and silica spin column kit designed for fatty and fibrous tissues significantly improve RNA quality. Using the pipeline that we developed, we show that it is possible to obtain large yields of intact RNA across the full depth of dolphin blubber with integrity values that exceed those reported thus far (up to 8.3) and that are suitable for stress biomarker discovery by RNA sequencing, facilitating health assessments of wild cetaceans sampled by remote biopsy.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13102499/",
    doi = "10.1093/conphys/coag029",
    openalex = "W7155404402",
    pmcid = "PMC13102499",
    pmid = "42027705",
    references = "doi101007s1039300400946, doi1010160003269787900212, doi101038nprot200683, doi101038s4157701901258, doi10108000031305198010483031, doi101126scienceaat1953, doi101126scienceaba4658, doi101186174170071242, doi1018637jssv067i01, doi101890130220"
}

In odontocete cetaceans (toothed whales, dolphins, and porpoises), a palatopharyngeal sphincter permanently anchors the laryngeal inlet in the nasopharynx and isolates the airway from the gut tube. Using an MRI data set of a pacific white-sided dolphin (Aethalodelphis obliquidens), together with dissections of the dolphin and two neonatal harbour porpoises (Phocoena phocoena), we show that the sphincter is formed by fusion of part of the superior constrictor of the pharyngeal wall to the soft palate. The part of the superior constrictor that participates in forming the sphincter is brought close to the midline by the presence of palatine plates that: (1) project medially from the ventral aspects of the pterygoid bone on each side, (2) lie caudal to the palatine bones of the hard palate where the soft palate normally attaches in other mammals, and (3) divide rostral parts of the soft palate into a part dorsal to the plates and a part ventral to the plates. Based on the presence and the anatomy of major muscles of the soft palate, we present a biomechanical model for how the palatopharyngeal sphincter functions and is positioned during swallowing and breathing. We conclude that the sphincter is most contracted during swallowing to hold the laryngeal inlet in position while large prey items pass through the laryngopharynx, and is most relaxed during breathing when the laryngeal inlet maximumly opens to allow unrestricted airflow.

@article{doi101093iobobag012,
    author = "Vogl, A W and Cieri, R and Palia, P and Shadwick, R and Cottrell, P and Raverty, S",
    title = "Fusion of the Pharyngeal Wall to the Soft Palate Around the Laryngeal Inlet Isolates the Airway in Odontocete Cetaceans.",
    year = "2026",
    journal = "Integrative organismal biology (Oxford, England)",
    abstract = "In odontocete cetaceans (toothed whales, dolphins, and porpoises), a palatopharyngeal sphincter permanently anchors the laryngeal inlet in the nasopharynx and isolates the airway from the gut tube. Using an MRI data set of a pacific white-sided dolphin (Aethalodelphis obliquidens), together with dissections of the dolphin and two neonatal harbour porpoises (Phocoena phocoena), we show that the sphincter is formed by fusion of part of the superior constrictor of the pharyngeal wall to the soft palate. The part of the superior constrictor that participates in forming the sphincter is brought close to the midline by the presence of palatine plates that: (1) project medially from the ventral aspects of the pterygoid bone on each side, (2) lie caudal to the palatine bones of the hard palate where the soft palate normally attaches in other mammals, and (3) divide rostral parts of the soft palate into a part dorsal to the plates and a part ventral to the plates. Based on the presence and the anatomy of major muscles of the soft palate, we present a biomechanical model for how the palatopharyngeal sphincter functions and is positioned during swallowing and breathing. We conclude that the sphincter is most contracted during swallowing to hold the laryngeal inlet in position while large prey items pass through the laryngopharynx, and is most relaxed during breathing when the laryngeal inlet maximumly opens to allow unrestricted airflow.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13070554/",
    doi = "10.1093/iob/obag012",
    openalex = "W7141573993",
    pmcid = "PMC13070554",
    pmid = "41978910",
    references = "doi101002ar1092180115, doi101002ar25597, doi101016jjcz201809005, doi101055s00391691756, doi101098rstb19400002, doi101111j109636421992tb00926x, doi101152jn195619144, doi104322jms100916, doi105479si00810282627, doi105603fma20210015"
}