Intertidal

1. An ecological survey of the fauna of Dingle Beach, Mersey Estuary, has been made. 2. A detailed analysis of the constituents of the mud, sand and gravel is given. 3. A quantitative analysis of the Molluscan fauna from a series of stations has been made. 4. Type of ground and fauna at different tidal levels are correlated. Mya arenaria is only found in abundance where there are stones. Macoma balthica is abundant wherever there is thick mud. 5. Dingle Beach is a type of Macoma community but differing markedly from the typical community described by Petersen as “d”. 6. The importance of sewage in producing silt and the part played by sewage in the food chain are discussed.

@article{doi101017s0025315400051304,
    author = "Fraser, J. H.",
    title = "Observations on the Fauna and Constituents of an Estuarine Mud in a Polluted Area",
    year = "1932",
    journal = "Journal of the Marine Biological Association of the United Kingdom",
    abstract = "1. An ecological survey of the fauna of Dingle Beach, Mersey Estuary, has been made. 2. A detailed analysis of the constituents of the mud, sand and gravel is given. 3. A quantitative analysis of the Molluscan fauna from a series of stations has been made. 4. Type of ground and fauna at different tidal levels are correlated. Mya arenaria is only found in abundance where there are stones. Macoma balthica is abundant wherever there is thick mud. 5. Dingle Beach is a type of Macoma community but differing markedly from the typical community described by Petersen as “d”. 6. The importance of sewage in producing silt and the part played by sewage in the food chain are discussed.",
    url = "https://doi.org/10.1017/s0025315400051304",
    doi = "10.1017/s0025315400051304",
    openalex = "W2152292992"
}

The 37 sq. miles of intertidal banks in the Mersey Estuary have been surveyed and classified according to their nature and fauna. Half the banks occur in the Outer and half in the Upper Estuary. Four-fifths of the total area is composed of sand and most of the remaining one-fifth of mud occurs in the Upper Estuary. The burrowing fauna of the Outer Estuary is abundant and varied; that of the Upper Estuary is abundant but not varied. The distribution of species in the Mersey Estuary is similar to that in the estuaries of the River Tees and Tay, except that in the Mersey Estuary a sudden drop in the numbers of species occurs at Rock Light. This is attributed o t the strong tidal streams in the Narrows. The densely inhabited banks of the Upper Estuary are mainly composed of mud and are situated high in the shore zone. In the Outer Estuary the densely inhabited banks are of muddy sand with some banks of mud and are situated near the low-water mark in sheltered positions. The burrowing species of the Upper Estuary also occur, with many others, in the Outer Estuary. The observations described in this paper were made during an investigation of the estuary of the River Mersey by the Water Pollution Board of the Department of Scientific and Industrial Research and the results are published by permission of the Department.

@article{bassindale1938the,
    author = "Bassindale, R.",
    title = "The intertidal fauna of the Mersey estuary",
    year = "1938",
    journal = "Journal of the Marine Biological Association of the United Kingdom",
    abstract = "The 37 sq. miles of intertidal banks in the Mersey Estuary have been surveyed and classified according to their nature and fauna. Half the banks occur in the Outer and half in the Upper Estuary. Four-fifths of the total area is composed of sand and most of the remaining one-fifth of mud occurs in the Upper Estuary. The burrowing fauna of the Outer Estuary is abundant and varied; that of the Upper Estuary is abundant but not varied. The distribution of species in the Mersey Estuary is similar to that in the estuaries of the River Tees and Tay, except that in the Mersey Estuary a sudden drop in the numbers of species occurs at Rock Light. This is attributed o t the strong tidal streams in the Narrows. The densely inhabited banks of the Upper Estuary are mainly composed of mud and are situated high in the shore zone. In the Outer Estuary the densely inhabited banks are of muddy sand with some banks of mud and are situated near the low-water mark in sheltered positions. The burrowing species of the Upper Estuary also occur, with many others, in the Outer Estuary. The observations described in this paper were made during an investigation of the estuary of the River Mersey by the Water Pollution Board of the Department of Scientific and Industrial Research and the results are published by permission of the Department.",
    url = "https://doi.org/10.1017/s0025315400053984",
    doi = "10.1017/s0025315400053984",
    number = "1",
    openalex = "W2113140291",
    pages = "83-98",
    volume = "23",
    references = "doi101017s0025315400051304, doi101017s0025315400055831, doi105962bhltitle16341"
}

An intensive investigation of 6 localities on the intertidal flats of Barnstable Harbor, Mass., was undertaken during the summer of 1959. The number of animals ranged 7,000– 355,000/m 2. The total dry weight varied from 17.6–60.2 g/m 2. A less detailed study was carried out on the same stations during the summer of 1960. A total of 82 species were collected during the 2‐year period. Stomach contents of 234 individuals representing 36 species showed that many of the forms considered to be carnivorous are, in reality, omnivores obtaining most of their food as deposit‐feeders. This explains why many of these species are present in such large numbers. With the exception of molluscs and crustaceans, the supposed carnivores, selective, and non‐selective deposit‐feeders can each be divided into three groups with respect to stomach contents: 1) Smaller species with only diatoms, detritus, and sand grains in the gut; 2) Intermediate‐sized species with these components plus fragments of macroalgae and occasional animal remains; 3) Larger species with conspicuous animal remains in the gut in addition to all the other components. Despite the fact that the sediment at 5 of the stations consisted almost entirely of fine sand with very little organic matter, most of the biomass (78%) was made up of animals that are primarily deposit‐feeders. The presence or absence of large populations of deposit‐feeders in sandy sediments was correlated with the stabiltiy of the sediment surface; in unstable sediments, as indicated by ripple marks, the standing crops were small; in stable sediments where the ripple marks were absent, dense concentrations of benthic diatoms and dinoflagellates were found which provide the major food source for the large biomass of deposit‐feeders. The chlorophyll readings obtained from the sediments were about intermediate between the highest values reported for sea water and a rich terrestrial environment. Observations were made on the natural history of the three dominant species: Gemma gemma, Glymenella torquata, and Glycera dibranchiata.

@article{doi104319lo1962710063,
    author = "Sanders, Howard L. and Goudsmit, E. M. and Mills, Edward L. and Hampson, G. E.",
    title = "A STUDY OF THE INTERTIDAL FAUNA OF BARNSTABLE HARBOR, MASSACHUSETTS1",
    year = "1962",
    journal = "Limnology and Oceanography",
    abstract = "An intensive investigation of 6 localities on the intertidal flats of Barnstable Harbor, Mass., was undertaken during the summer of 1959. The number of animals ranged 7,000– 355,000/m 2. The total dry weight varied from 17.6–60.2 g/m 2. A less detailed study was carried out on the same stations during the summer of 1960. A total of 82 species were collected during the 2‐year period. Stomach contents of 234 individuals representing 36 species showed that many of the forms considered to be carnivorous are, in reality, omnivores obtaining most of their food as deposit‐feeders. This explains why many of these species are present in such large numbers. With the exception of molluscs and crustaceans, the supposed carnivores, selective, and non‐selective deposit‐feeders can each be divided into three groups with respect to stomach contents: 1) Smaller species with only diatoms, detritus, and sand grains in the gut; 2) Intermediate‐sized species with these components plus fragments of macroalgae and occasional animal remains; 3) Larger species with conspicuous animal remains in the gut in addition to all the other components. Despite the fact that the sediment at 5 of the stations consisted almost entirely of fine sand with very little organic matter, most of the biomass (78\%) was made up of animals that are primarily deposit‐feeders. The presence or absence of large populations of deposit‐feeders in sandy sediments was correlated with the stabiltiy of the sediment surface; in unstable sediments, as indicated by ripple marks, the standing crops were small; in stable sediments where the ripple marks were absent, dense concentrations of benthic diatoms and dinoflagellates were found which provide the major food source for the large biomass of deposit‐feeders. The chlorophyll readings obtained from the sediments were about intermediate between the highest values reported for sea water and a rich terrestrial environment. Observations were made on the natural history of the three dominant species: Gemma gemma, Glymenella torquata, and Glycera dibranchiata.",
    url = "https://doi.org/10.4319/lo.1962.7.1.0063",
    doi = "10.4319/lo.1962.7.1.0063",
    openalex = "W2023887036",
    references = "doi101002jmor1050130202, doi101017s0025315400055132, doi101038187123a0, doi101127novahedwigia301979697, doi101163156854062x00201, doi104319lo1958330245, doi104319lo1959440448, doi104319lo1960520138"
}

Summary 1. The study of the microfauna living in the interstitial water in marine or freshwater sand, the so‐called interstitial or mesopsammic fauna, has made important contributions to systematic zoology during the past four decades. Most invertebrate groups are represented, and many of the morphologically aberrant forms of animals discovered in this environment belong to quite new structural types. Among the discoveries are animal groups of high systematic rank, such as the orders Actinulida (Coelenterata), Gnathostomulida (Turbellaria), Mystacocarida (Crustacea) and Acochlidiacea (Mollusca). 2. The coastal subsoil water is the environment of a special interstitial brackish‐water fauna, which has been studied intensively along the beaches of Europe. This zone may be regarded as a transitional area between the submerged marine sand and the continental subterranean waters with their phreatic freshwater fauna. 3. One ecological factor of prime significance is that of space, which is dependent on the grain size distribution in a sediment, and which determines the upper size limit of organisms in a given interstitial environment. The granulometric characteristics of the sand affect the composition of the microbiocoenoses and their distribution within a beach area. 4. Wind, waves and currents cause a continuous rearrangement of the particles in the surface layer of the sand. The interstitial system of the sand is therefore most usually a very dynamic environment with special biological conditions. 5. Such physical factors as temperature and salinity vary greatly in many interstitial biotopes, particularly in the tidal zone. This implies that the interstitial organisms are physiologically adapted to endure both the seasonal variation and the often rapid changes that occur in connexion with ebb and flood. The littoral interstitial fauna is therefore eurythermal and euryhaline. 6. The vertical distribution of the interstitial fauna in a sandy beach varies with the situation in relation to low‐ and high‐water marks. The vertical and also the horizontal distribution of the microfauna in a beach show a marked variation with the season of the year, which is usually manifested as a migration towards greater depth during the colder part of the year. 7. It is in the interstitial fauna that we find the very smallest representatives of most of the invertebrate phyla. Body sizes vary from about 0.5 to a few millimetres, and only thread‐shaped organisms are longer than this. Protozoa and Metozoa in this environment have about the same dimensions. Examples of morphological regression in the interstitial fauna suggest that body lengths of about 0.5–1 mm. may be the low size limit for invertebrates. 8. Certain shapes of body dominate in the interstitial fauna. Elongated forms are favoured; vermiformity is common and may occur in groups of animals in which such a body shape is unusual (the coelenterate Halammohydra, the opisthobranch Pseudovermis and others). Another type is represented by the broad and flat forms. 9. Morphological adaptations to the biological demands of the dynamic environment are found. These consist of (a) different kinds of reinforcement of the body wall, such as cuticular scales or spines (gastrotrichs, solenogastrids) or epidermal spicules (turbellarians, opisthobranchs), which are of importance as mechanical protection; (b) an often marked ability of contraction serves a similar purpose in organisms with thin body walls (ciliates, turbellarians, gastrotrichs and others); (c) adhesive organs are found in most species, and attachment is by adhesive glands or various kinds of gripping organs; (d) static sense organs are common in different groups of animals and the importance of such organs in a dynamic environment is obvious. 10. As regards modes of nutrition, the following categories dominate: (a) predators, e.g. coelenterates, turbellarians, nematodes; (b) diatom‐ and epi‐growth feeders, which may be divided into browsers (archiannelids, crustaceans, molluscs), pump‐suckers (some turbellarians, gastrotrichs, nematodes, Psammodrilus), puncture‐suckers (tardigrades) and sand‐lickers (certain amphipods, cumaceans); (c) detritus‐feeders (some gastrotrichs, nematodes and archiannelids); (d) suspension‐feeders (sedentary forms: Monobryoxoon, a brachiopod Gwynia and the interstitial ascidians). 11. The production of gametes is usually low; 1–10 ova per female at a time is normal. Adaptations for the maintenance of the populations of low‐producing species are: (a) spermatophores to ensure fertilization, e.g. Protodrilus, Microhedyle; (b) embryonic and larval development in cocoons, fixed to the substratum; (c) larval development with the suppression of a pelagic phase; (d) brood protection, e.g. Otohydra, Neril‐lidae; (e) considerable extension of the period of reproduction. 12. The Ciliata are important in the sand microfauna, where they are represented by almost 90 genera. The ciliates of fine‐sand habitats have been found to be the best adapted to interstitial conditions (microporal ciliates). 13. Coelenterates are represented by a rather small number of strongly aberrant forms. Among the Hydrozoa the genus Halammohydra is the best known. The genus forms a morphological series with transitions from ovoid to vermiform species, each adapted to definite interstitial environments, The peculiar bipolar genus Sphenotrochus represents the Madreporaria. 14. Of the two orders of gastrotrichs, the Macrodasyoidea, with its ca. 70 species, occurs exclusively in the interstitial fauna; the Chaetonotoidea are also common here, though this particular group has its main distribution in fresh waters. The macro‐dasyoid gastrotrichs are one of the groups characteristic of the sand microfauna, and provide possibilities for us to study different kinds of adaptation to the conditions of the environment. 15. The turbellarians comprise a large and varied group found in practically all types of sand biotopes. Those best adapted to the interstitial conditions are the Kaly‐ptorhynchia, and the Otoplanidae family. The order Gnathostomulida is one of the newly discovered aberrant groups. Members of this group are reminiscent of the familiar turbellarians, but differ in important structural features (cuticular pharyngeal jaws, polygonal epidermal epithelium). 16. The Nematoda in the sand fauna are rich in species and occur not infrequently in very large numbers. The distribution of the species in different sand biotopes has proved to be dependent on such ecological factors as grain size and supply of food. 17. The undoubtedly polyphyletic Archiannelida form one of the more characteristic groups of the interstitial fauna. Sixty or so interstitial species are known, but only few from other biotopes. 18. Ostracoda, Mystacocarida, Copepoda and Isopoda are the most important groups of crustaceans in marine sand. Elongated body forms or elongated shell types (Ostracoda) are common in the interstitial species. The order Mystacocarida, discovered in 1943, is known exclusively from the interstitial fauna, mainly in coastal subsoil water. These very small crustaceans, related to the copepods, have played an important role in phylogenetic discussions. 19. The best represented of the mollusc groups are the Opisthobranchia, with the order Acochlidiacea, containing ten species in the size range of 0.8–3 mm., and more or less vermiform. Other typical sand microforms are the genera Rhodope, Pseudovermis and Philinoglossa. The groups of molluscs in the sand microfauna to which least attention has been paid are the solenogastrids, which are represented in the so‐called Amphioxus‐ sand by species about a millimetre long. 20. The remarkable Monobryozoon ambulans is the only bryozoan in this environment. It has a restricted locomotive ability and may be regarded as semi‐sessile. 21. The Echinodermata are represented by a few synaptids a couple of millimetres long, e.g. Leptosynapta minuta, which by shape of body, method of locomotion, adhesive ability, static organs, etc., is very well adapted to life in the interstitial environment. 22. Recently discovered interstitial Ascidiacea are related to benthic forms in the macrofauna, where they belong to various families. Some of the interstitial species have a certain locomotive ability, due to muscle activity.

@article{doi101111j1469185x1964tb00948x,
    author = "SWEDMARK, BERTIL",
    title = "THE INTERSTITIAL FAUNA OF MARINE SAND",
    year = "1964",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "Summary 1. The study of the microfauna living in the interstitial water in marine or freshwater sand, the so‐called interstitial or mesopsammic fauna, has made important contributions to systematic zoology during the past four decades. Most invertebrate groups are represented, and many of the morphologically aberrant forms of animals discovered in this environment belong to quite new structural types. Among the discoveries are animal groups of high systematic rank, such as the orders Actinulida (Coelenterata), Gnathostomulida (Turbellaria), Mystacocarida (Crustacea) and Acochlidiacea (Mollusca). 2. The coastal subsoil water is the environment of a special interstitial brackish‐water fauna, which has been studied intensively along the beaches of Europe. This zone may be regarded as a transitional area between the submerged marine sand and the continental subterranean waters with their phreatic freshwater fauna. 3. One ecological factor of prime significance is that of space, which is dependent on the grain size distribution in a sediment, and which determines the upper size limit of organisms in a given interstitial environment. The granulometric characteristics of the sand affect the composition of the microbiocoenoses and their distribution within a beach area. 4. Wind, waves and currents cause a continuous rearrangement of the particles in the surface layer of the sand. The interstitial system of the sand is therefore most usually a very dynamic environment with special biological conditions. 5. Such physical factors as temperature and salinity vary greatly in many interstitial biotopes, particularly in the tidal zone. This implies that the interstitial organisms are physiologically adapted to endure both the seasonal variation and the often rapid changes that occur in connexion with ebb and flood. The littoral interstitial fauna is therefore eurythermal and euryhaline. 6. The vertical distribution of the interstitial fauna in a sandy beach varies with the situation in relation to low‐ and high‐water marks. The vertical and also the horizontal distribution of the microfauna in a beach show a marked variation with the season of the year, which is usually manifested as a migration towards greater depth during the colder part of the year. 7. It is in the interstitial fauna that we find the very smallest representatives of most of the invertebrate phyla. Body sizes vary from about 0.5 to a few millimetres, and only thread‐shaped organisms are longer than this. Protozoa and Metozoa in this environment have about the same dimensions. Examples of morphological regression in the interstitial fauna suggest that body lengths of about 0.5–1 mm. may be the low size limit for invertebrates. 8. Certain shapes of body dominate in the interstitial fauna. Elongated forms are favoured; vermiformity is common and may occur in groups of animals in which such a body shape is unusual (the coelenterate Halammohydra, the opisthobranch Pseudovermis and others). Another type is represented by the broad and flat forms. 9. Morphological adaptations to the biological demands of the dynamic environment are found. These consist of (a) different kinds of reinforcement of the body wall, such as cuticular scales or spines (gastrotrichs, solenogastrids) or epidermal spicules (turbellarians, opisthobranchs), which are of importance as mechanical protection; (b) an often marked ability of contraction serves a similar purpose in organisms with thin body walls (ciliates, turbellarians, gastrotrichs and others); (c) adhesive organs are found in most species, and attachment is by adhesive glands or various kinds of gripping organs; (d) static sense organs are common in different groups of animals and the importance of such organs in a dynamic environment is obvious. 10. As regards modes of nutrition, the following categories dominate: (a) predators, e.g. coelenterates, turbellarians, nematodes; (b) diatom‐ and epi‐growth feeders, which may be divided into browsers (archiannelids, crustaceans, molluscs), pump‐suckers (some turbellarians, gastrotrichs, nematodes, Psammodrilus), puncture‐suckers (tardigrades) and sand‐lickers (certain amphipods, cumaceans); (c) detritus‐feeders (some gastrotrichs, nematodes and archiannelids); (d) suspension‐feeders (sedentary forms: Monobryoxoon, a brachiopod Gwynia and the interstitial ascidians). 11. The production of gametes is usually low; 1–10 ova per female at a time is normal. Adaptations for the maintenance of the populations of low‐producing species are: (a) spermatophores to ensure fertilization, e.g. Protodrilus, Microhedyle; (b) embryonic and larval development in cocoons, fixed to the substratum; (c) larval development with the suppression of a pelagic phase; (d) brood protection, e.g. Otohydra, Neril‐lidae; (e) considerable extension of the period of reproduction. 12. The Ciliata are important in the sand microfauna, where they are represented by almost 90 genera. The ciliates of fine‐sand habitats have been found to be the best adapted to interstitial conditions (microporal ciliates). 13. Coelenterates are represented by a rather small number of strongly aberrant forms. Among the Hydrozoa the genus Halammohydra is the best known. The genus forms a morphological series with transitions from ovoid to vermiform species, each adapted to definite interstitial environments, The peculiar bipolar genus Sphenotrochus represents the Madreporaria. 14. Of the two orders of gastrotrichs, the Macrodasyoidea, with its ca. 70 species, occurs exclusively in the interstitial fauna; the Chaetonotoidea are also common here, though this particular group has its main distribution in fresh waters. The macro‐dasyoid gastrotrichs are one of the groups characteristic of the sand microfauna, and provide possibilities for us to study different kinds of adaptation to the conditions of the environment. 15. The turbellarians comprise a large and varied group found in practically all types of sand biotopes. Those best adapted to the interstitial conditions are the Kaly‐ptorhynchia, and the Otoplanidae family. The order Gnathostomulida is one of the newly discovered aberrant groups. Members of this group are reminiscent of the familiar turbellarians, but differ in important structural features (cuticular pharyngeal jaws, polygonal epidermal epithelium). 16. The Nematoda in the sand fauna are rich in species and occur not infrequently in very large numbers. The distribution of the species in different sand biotopes has proved to be dependent on such ecological factors as grain size and supply of food. 17. The undoubtedly polyphyletic Archiannelida form one of the more characteristic groups of the interstitial fauna. Sixty or so interstitial species are known, but only few from other biotopes. 18. Ostracoda, Mystacocarida, Copepoda and Isopoda are the most important groups of crustaceans in marine sand. Elongated body forms or elongated shell types (Ostracoda) are common in the interstitial species. The order Mystacocarida, discovered in 1943, is known exclusively from the interstitial fauna, mainly in coastal subsoil water. These very small crustaceans, related to the copepods, have played an important role in phylogenetic discussions. 19. The best represented of the mollusc groups are the Opisthobranchia, with the order Acochlidiacea, containing ten species in the size range of 0.8–3 mm., and more or less vermiform. Other typical sand microforms are the genera Rhodope, Pseudovermis and Philinoglossa. The groups of molluscs in the sand microfauna to which least attention has been paid are the solenogastrids, which are represented in the so‐called Amphioxus‐ sand by species about a millimetre long. 20. The remarkable Monobryozoon ambulans is the only bryozoan in this environment. It has a restricted locomotive ability and may be regarded as semi‐sessile. 21. The Echinodermata are represented by a few synaptids a couple of millimetres long, e.g. Leptosynapta minuta, which by shape of body, method of locomotion, adhesive ability, static organs, etc., is very well adapted to life in the interstitial environment. 22. Recently discovered interstitial Ascidiacea are related to benthic forms in the macrofauna, where they belong to various families. Some of the interstitial species have a certain locomotive ability, due to muscle activity.",
    url = "https://doi.org/10.1111/j.1469-185x.1964.tb00948.x",
    doi = "10.1111/j.1469-185x.1964.tb00948.x",
    openalex = "W2066775421"
}

The herbivorous gastropod Tegula funebralis is not highly ranked in a food preference hierarchy of its major predator, the starfish Pisaster ochraceus, and exhibits a persistent broad overlap with it in the rocky intertidal zone at Mukkaw Bay, Washington. Observations on Tegula over a 5—yr period indicate that it settles high intertidally, lives there for 5—6 yr, and then tends to migrate lower into contact with Pisaster. Tegula lays down an annual growth line permitting it to be aged and a growth curve constructed. Analysis of relative growth and reproduction indicates that beyond a certain size (16 mm) large individuals perform less well in the upper than those in the lower intertidal zone. Pisaster consumes 25—28% of the adult Tegula per year in the area of spatial overlap, based on analysis of the age structure of 6—17 yr old Tegula, and by direct estimates of the percentage of the standing crop consumed annually. The relationship between Pisaster and sex ratio, relative energy limitation and reproductive output (fitness) of Tegula is discussed for three subpopulations. It is suggested that the implied results of the interaction is typical of that between a major predator and one of its less preferred prey. The prominent zonation exhibited by preferred prey, the observed intimacy of association of predator and less preferred prey, and the zoogeographic homogeneity of the Pacific rocky coastline community are discussed in relation to three intermeshing ecological processes.

@article{doi1023071936888,
    author = "Paine, Robert T.",
    title = "The Pisaster‐Tegula Interaction: Prey Patches, Predator Food Preference, and Intertidal Community Structure",
    year = "1969",
    journal = "Ecology",
    abstract = "The herbivorous gastropod Tegula funebralis is not highly ranked in a food preference hierarchy of its major predator, the starfish Pisaster ochraceus, and exhibits a persistent broad overlap with it in the rocky intertidal zone at Mukkaw Bay, Washington. Observations on Tegula over a 5—yr period indicate that it settles high intertidally, lives there for 5—6 yr, and then tends to migrate lower into contact with Pisaster. Tegula lays down an annual growth line permitting it to be aged and a growth curve constructed. Analysis of relative growth and reproduction indicates that beyond a certain size (16 mm) large individuals perform less well in the upper than those in the lower intertidal zone. Pisaster consumes 25—28\% of the adult Tegula per year in the area of spatial overlap, based on analysis of the age structure of 6—17 yr old Tegula, and by direct estimates of the percentage of the standing crop consumed annually. The relationship between Pisaster and sex ratio, relative energy limitation and reproductive output (fitness) of Tegula is discussed for three subpopulations. It is suggested that the implied results of the interaction is typical of that between a major predator and one of its less preferred prey. The prominent zonation exhibited by preferred prey, the observed intimacy of association of predator and less preferred prey, and the zoogeographic homogeneity of the Pacific rocky coastline community are discussed in relation to three intermeshing ecological processes.",
    url = "https://doi.org/10.2307/1936888",
    doi = "10.2307/1936888",
    openalex = "W2029732055",
    references = "doi101071zo9540001, doi101086282400, doi101086282586, doi101126science150369228, doi1023071439791, doi1023071539653, doi1023071932529, doi1023071935526, doi105479si03629236931, openalexw331418603"
}

An understanding of community structure should be based on evidence that the growth and regulation of the component populations in the community are affected in a predictable manner by natural physical disturbances and by interactions with other species in the community. This study presents an experimental evaluation of the effects of such disturbances and competitive interactions on populations of sessile organisms in the rocky intertidal community, for which space can be demonstrated to be the most important limiting resource. This research was carried out at eight stations on the Washington coastline which have been ranked according to an exposure/desiccation gradient and subjected to comparable manipulation and observation. Physical variables such as wave exposure, battering by drift logs, and desiccation have important effects on the distribution and abundance of many of the sessile species in the community. In particular, wave exposure and desiccation have a major influence on the distribution patterns of all the algae and of the anemone Anthopleura elegantissima. The probability of damage from drift logs is very high in areas where logs have accumulated along the intertidal. Log damage and wave exposure have complementary effects in the provision of free space in a mussel bed, as wave shock enlarges a patch created by log damage by wrenching the mussels from the substratum at the periphery of the bare patch. Competition for primary space results in clear dominance hierarchies, in which barnacles are dominant over algae. Among the barnacles, Balanus cariosus is dominant over both B. glandula and Chthamalus dalli; B. glandula is dominant over C. dalli. The mussel Mytilus californianus requires secondary space (certain algae, barnacles, or byssal threads) for larval settlement, but is capable of growing over all other sessile species and potentially is the competitive dominant of space in the community.

@article{dayton1971competition,
    author = "Dayton, Paul K.",
    title = "Competition, Disturbance, and Community Organization: The Provision and Subsequent Utilization of Space in a Rocky Intertidal Community",
    year = "1971",
    journal = "Ecological Monographs",
    abstract = "An understanding of community structure should be based on evidence that the growth and regulation of the component populations in the community are affected in a predictable manner by natural physical disturbances and by interactions with other species in the community. This study presents an experimental evaluation of the effects of such disturbances and competitive interactions on populations of sessile organisms in the rocky intertidal community, for which space can be demonstrated to be the most important limiting resource. This research was carried out at eight stations on the Washington coastline which have been ranked according to an exposure/desiccation gradient and subjected to comparable manipulation and observation. Physical variables such as wave exposure, battering by drift logs, and desiccation have important effects on the distribution and abundance of many of the sessile species in the community. In particular, wave exposure and desiccation have a major influence on the distribution patterns of all the algae and of the anemone Anthopleura elegantissima. The probability of damage from drift logs is very high in areas where logs have accumulated along the intertidal. Log damage and wave exposure have complementary effects in the provision of free space in a mussel bed, as wave shock enlarges a patch created by log damage by wrenching the mussels from the substratum at the periphery of the bare patch. Competition for primary space results in clear dominance hierarchies, in which barnacles are dominant over algae. Among the barnacles, Balanus cariosus is dominant over both B. glandula and Chthamalus dalli; B. glandula is dominant over C. dalli. The mussel Mytilus californianus requires secondary space (certain algae, barnacles, or byssal threads) for larval settlement, but is capable of growing over all other sessile species and potentially is the competitive dominant of space in the community.",
    url = "https://doi.org/10.2307/1948498",
    doi = "10.2307/1948498",
    number = "4",
    openalex = "W1974072473",
    pages = "351-389",
    volume = "41",
    references = "connell1961effects, doi101086282400, doi101086282455, doi101126science1473655250, doi1023071931746, doi1023071933500, doi1023071936888, doi1023071942327, doi1023073498751, doi102307jctvx5wbbh"
}

The mechanisms by which various species exert influence disproportionate to their abundance or mass on the structure of a lower intertidal algal community were evaluated experimentally. These functional roles were evaluated experimentally. These functional roles were evaluated by various controlled manipulations at seven stations along the Washington coastline ranked according to an exposure/desiccation gradient. The algae were divided into three categories: canopy species, which grow above the other species and apparently succeed in competitively dominating the light resources as demonstrated by algal blooms following their removal; obligate understory species, which die after the canopy species are removed; and fugitive species, which are quick to colonize new space. Ecological dominance was exerted in areas of moderate wave exposure by Hedophyllum sessile, which competitively displaces a large number of fugitive algal species and which furnishes a protected habitat for many obligate understory algae that die or defoliate after the removal of Hedophyllum. Hedophyllum loses this dominance in the most exposed areas, although such sites apparently represent its physiologically optimal habitat, because in these areas it is out—competed by Laminaria setchellii and Lessoniopsis littoralis. In these wave exposed habitats Lessoniopsis was demonstrated to exert a strong competitive dominance over all the other species in the association. The molluscan herbivores were not observed to express any measurable effects on the recruitment or survival of the algae. However, the echinoid Strongylocentrotus purpuratus often overexploits its prey and has a pronounced influence on most of the algal species. In this respect S. purpuratus enjoys an important community role singular among the many herbivores. Similarly, Pycnopodia helianthoides and Anthopleura xanthogrammica are disproportionately important carnivores, because their predation on Strongylocentrotus, clearing large areas of urchins, results in patches in which algal succession follows. The rate of algal succession following removal of the dominant algal species or of Strongylocentrotus is proportional to the degree of wave exposure. The Hedophyllum canopy recovery at the Eagle Point area of San Juan Island, a site exposed to relatively little wave action and thus high levels of desiccation, was relatively slow, with only 10%—26% cover reestablished after 3 yr. In contrast, Hedophyllum canopy developed up to 66% cover in only 1 yr in the exposed area of Waadah Island; it then quickly lost its dominance to Laminaria and Lessoniopsis. Algal succession in deeper Portage Head tidepools was found to be relatively slow with no clear dominance expressed after 5 yr.

@article{doi1023071942404,
    author = "Dayton, Paul K.",
    title = "Experimental Evaluation of Ecological Dominance in a Rocky Intertidal Algal Community",
    year = "1975",
    journal = "Ecological Monographs",
    abstract = "The mechanisms by which various species exert influence disproportionate to their abundance or mass on the structure of a lower intertidal algal community were evaluated experimentally. These functional roles were evaluated experimentally. These functional roles were evaluated by various controlled manipulations at seven stations along the Washington coastline ranked according to an exposure/desiccation gradient. The algae were divided into three categories: canopy species, which grow above the other species and apparently succeed in competitively dominating the light resources as demonstrated by algal blooms following their removal; obligate understory species, which die after the canopy species are removed; and fugitive species, which are quick to colonize new space. Ecological dominance was exerted in areas of moderate wave exposure by Hedophyllum sessile, which competitively displaces a large number of fugitive algal species and which furnishes a protected habitat for many obligate understory algae that die or defoliate after the removal of Hedophyllum. Hedophyllum loses this dominance in the most exposed areas, although such sites apparently represent its physiologically optimal habitat, because in these areas it is out—competed by Laminaria setchellii and Lessoniopsis littoralis. In these wave exposed habitats Lessoniopsis was demonstrated to exert a strong competitive dominance over all the other species in the association. The molluscan herbivores were not observed to express any measurable effects on the recruitment or survival of the algae. However, the echinoid Strongylocentrotus purpuratus often overexploits its prey and has a pronounced influence on most of the algal species. In this respect S. purpuratus enjoys an important community role singular among the many herbivores. Similarly, Pycnopodia helianthoides and Anthopleura xanthogrammica are disproportionately important carnivores, because their predation on Strongylocentrotus, clearing large areas of urchins, results in patches in which algal succession follows. The rate of algal succession following removal of the dominant algal species or of Strongylocentrotus is proportional to the degree of wave exposure. The Hedophyllum canopy recovery at the Eagle Point area of San Juan Island, a site exposed to relatively little wave action and thus high levels of desiccation, was relatively slow, with only 10\%—26\% cover reestablished after 3 yr. In contrast, Hedophyllum canopy developed up to 66\% cover in only 1 yr in the exposed area of Waadah Island; it then quickly lost its dominance to Laminaria and Lessoniopsis. Algal succession in deeper Portage Head tidepools was found to be relatively slow with no clear dominance expressed after 5 yr.",
    url = "https://doi.org/10.2307/1942404",
    doi = "10.2307/1942404",
    openalex = "W2041491516",
    references = "doi1023071935526, doi1023071936888, doi1023071942321"
}

How much of a living marine fauna would be reflected in the fossil record? In order to answer this, I investigated the probable fate of 169 megascopic genera of the intertidal fauna of the Friday Harbor, Washington region. Three methods were used and these give very similar results. (I) From morphologic examination, 30% of the mud fauna, 32% of the sand fauna, and 29% of the rock fauna are predicted to yield many identifiable fossils; 38% of the mud fauna, 42% of the sand fauna, and 41% of the rock fauna are predicted to yield few identifiable fossils; and the remainder are predicted to yield no fossils. (II) In actual fact, 44% of the mud fauna, 32% of the sand fauna, and 39% of the rock fauna have a fossil record (data from Treatise on Invertebrate Paleontology). (III) The 16 sediment samples which were examined yielded 29% of the total fauna. I conclude (1) that the fossilization potential for the Friday Harbor intertidal fauna is largely independent of habitat, and (2) that 40% of the present megascopic fauna would be (and has been!) preserved in the fossil record. The fossil record would accurately (and preferentially) include the herbivore and filter feeding genera. The reason which I postulate for this is based on the suitability of heavily calcified exoskeletons to an essentially sessile mode of life, and the lack of suitability of such skeletons for readily mobile forms. 67% of the genera which essentially rest in one place are known as fossils. In contrast, only 16 to 27% of the burrowing detritus eaters (e.g., polychaetes) and roving carnivores (e.g., sea stars and crabs) are known as fossils. The percentage of herbivore and filter feeding genera in rocky environments is 39%, in sand 16% and in mud 34%. In the fossil record, deposits which were originally mud are likely to be most fossiliferous because (1) that environment has a high proportion of essentially sessile genera, (2) essentially sessile genera are far more likely to have a heavily calcified skeleton, and (3) few rock intertidal regions are buried.

@article{doi101017s0094837300005996,
    author = "Schöpf, Thomas J. M.",
    title = "Fossilization potential of an intertidal fauna: Friday Harbor, Washington",
    year = "1978",
    journal = "Paleobiology",
    abstract = "How much of a living marine fauna would be reflected in the fossil record? In order to answer this, I investigated the probable fate of 169 megascopic genera of the intertidal fauna of the Friday Harbor, Washington region. Three methods were used and these give very similar results. (I) From morphologic examination, 30\% of the mud fauna, 32\% of the sand fauna, and 29\% of the rock fauna are predicted to yield many identifiable fossils; 38\% of the mud fauna, 42\% of the sand fauna, and 41\% of the rock fauna are predicted to yield few identifiable fossils; and the remainder are predicted to yield no fossils. (II) In actual fact, 44\% of the mud fauna, 32\% of the sand fauna, and 39\% of the rock fauna have a fossil record (data from Treatise on Invertebrate Paleontology). (III) The 16 sediment samples which were examined yielded 29\% of the total fauna. I conclude (1) that the fossilization potential for the Friday Harbor intertidal fauna is largely independent of habitat, and (2) that 40\% of the present megascopic fauna would be (and has been!) preserved in the fossil record. The fossil record would accurately (and preferentially) include the herbivore and filter feeding genera. The reason which I postulate for this is based on the suitability of heavily calcified exoskeletons to an essentially sessile mode of life, and the lack of suitability of such skeletons for readily mobile forms. 67\% of the genera which essentially rest in one place are known as fossils. In contrast, only 16 to 27\% of the burrowing detritus eaters (e.g., polychaetes) and roving carnivores (e.g., sea stars and crabs) are known as fossils. The percentage of herbivore and filter feeding genera in rocky environments is 39\%, in sand 16\% and in mud 34\%. In the fossil record, deposits which were originally mud are likely to be most fossiliferous because (1) that environment has a high proportion of essentially sessile genera, (2) essentially sessile genera are far more likely to have a heavily calcified skeleton, and (3) few rock intertidal regions are buried.",
    url = "https://doi.org/10.1017/s0094837300005996",
    doi = "10.1017/s0094837300005996",
    openalex = "W2505387446",
    references = "doi101016s0016787876800077, doi101017s0094837300005236, doi101017s0094837300005248, doi101086282400, doi101111j143904691975tb00509x, doi101126science1924238461, doi1023071935526, doi1023071942565, openalexw1549886310, openalexw574363047"
}

How much of a living marine fauna would be reflected in the fossil record? In order to answer this, I investigated the probable fate of 169 megascopic genera of the intertidal fauna of the Friday Harbor, Washington region. Three methods were used and these give very similar results. (I) From morphologic examination, 30% of the mud fauna, 32% of the sand fauna, and 29% of the rock fauna are predicted to yield many identifiable fossils; 38% of the mud fauna, 42% of the sand fauna, and 41% of the rock fauna are predicted to yield few identifiable fossils; and the remainder are predicted to yield no fossils. (II) In actual fact, 44% of the mud fauna, 32% of the sand fauna, and 39% of the rock fauna have a fossil record (data from Treatise on Invertebrate Paleontology). (III) The 16 sediment samples which were examined yielded 29% of the total fauna. I conclude (1) that the fossilization potential for the Friday Harbor intertidal fauna is largely independent of habitat, and (2) that 40% of the present megascopic fauna would be (and has been!) preserved in the fossil record. The fossil record would accurately (and preferentially) include the herbivore and filter feeding genera. The reason which I postulate for this is based on the suitability of heavily calcified exoskeletons to an essentially sessile mode of life, and the lack of suitability of such skeletons for readily mobile forms. 67% of the genera which essentially rest in one place are known as fossils. In contrast, only 16 to 27% of the burrowing detritus eaters (e.g., polychaetes) and roving carnivores (e.g., sea stars and crabs) are known as fossils. The percentage of herbivore and filter feeding genera in rocky environments is 39%, in sand 16% and in mud 34%. In the fossil record, deposits which were originally mud are likely to be most fossiliferous because (1) that environment has a high proportion of essentially sessile genera, (2) essentially sessile genera are far more likely to have a heavily calcified skeleton, and (3) few rock intertidal regions are buried.

@article{schopf1978fossilization,
    author = "Schopf, Thomas J. M.",
    title = "Fossilization potential of an intertidal fauna: Friday Harbor, Washington",
    year = "1978",
    journal = "Paleobiology",
    abstract = "How much of a living marine fauna would be reflected in the fossil record? In order to answer this, I investigated the probable fate of 169 megascopic genera of the intertidal fauna of the Friday Harbor, Washington region. Three methods were used and these give very similar results. (I) From morphologic examination, 30\% of the mud fauna, 32\% of the sand fauna, and 29\% of the rock fauna are predicted to yield many identifiable fossils; 38\% of the mud fauna, 42\% of the sand fauna, and 41\% of the rock fauna are predicted to yield few identifiable fossils; and the remainder are predicted to yield no fossils. (II) In actual fact, 44\% of the mud fauna, 32\% of the sand fauna, and 39\% of the rock fauna have a fossil record (data from Treatise on Invertebrate Paleontology). (III) The 16 sediment samples which were examined yielded 29\% of the total fauna. I conclude (1) that the fossilization potential for the Friday Harbor intertidal fauna is largely independent of habitat, and (2) that 40\% of the present megascopic fauna would be (and has been!) preserved in the fossil record. The fossil record would accurately (and preferentially) include the herbivore and filter feeding genera. The reason which I postulate for this is based on the suitability of heavily calcified exoskeletons to an essentially sessile mode of life, and the lack of suitability of such skeletons for readily mobile forms. 67\% of the genera which essentially rest in one place are known as fossils. In contrast, only 16 to 27\% of the burrowing detritus eaters (e.g., polychaetes) and roving carnivores (e.g., sea stars and crabs) are known as fossils. The percentage of herbivore and filter feeding genera in rocky environments is 39\%, in sand 16\% and in mud 34\%. In the fossil record, deposits which were originally mud are likely to be most fossiliferous because (1) that environment has a high proportion of essentially sessile genera, (2) essentially sessile genera are far more likely to have a heavily calcified skeleton, and (3) few rock intertidal regions are buried.",
    url = "https://doi.org/10.1017/s0094837300005996",
    doi = "10.1017/s0094837300005996",
    number = "3",
    openalex = "W2505387446",
    pages = "261-270",
    volume = "4",
    references = "doi101016s0016787876800077, doi101017s0094837300005236, doi101017s0094837300005248, doi101086282400, doi101111j143904691975tb00509x, doi101126science1924238461, doi1023071935526, doi1023071942565, openalexw1549886310, openalexw574363047"
}

@misc{schopf1978fossilization1,
    author = "Schopf, T. J. M",
    title = "Fossilization potential of an intertidal fauna",
    year = "1978",
    howpublished = "Friday Harbor, Washington: Paleobiology, v. 4, p. 261-270",
    note = "talkorigins\_source = {true}; raw\_reference = {Schopf, T. J. M., 1978, Fossilization potential of an intertidal fauna: Friday Harbor, Washington: Paleobiology, v. 4, p. 261-270.}"
}

The effects of disturbance on local species diversity were investigated in an algaldominated intertidal boulder field in southern California. In this habitat, the major form of disturbance occurs when waves, generated by winter storms, overturn boulders. These natural physical disturbances open space, interrupt successional sequences, and determine local levels of species diversity. Because small boulders are more frequently overturned than larger ones, the plants and sessile animals of boulder fields are distributed in a patchwork of successional stages. Boulders which are subjected to intermediate disturbance frequencies are usually less dominated than those which are very frequently disturbed, and always less dominated than those which are seldon disturbed. In all seasons most small boulders have fewer species than those of intermediate size. Large boulders also usually have fewer species, except in the spring, when defoliation of the algal canopy during the previous winter has opened space for colonization. Species richness on these boulders declines during summer months, and is less than that on boulders of intermediate size in the fall. Small boulders, with a shorter disturbance interval, support only sparse early successional communities of the green alga, Ulva, and barnacles. Large, infrequently disturbed boulders are dominated by the late successional red alga, Gigartina canaliculata. Intermediate—sized boulders support the most diverse communities composed of Ulva, barnacles, several middle successional species of red algae, and Gigartina canaliculata. Comparison of the pattern of succession on experimentally stabilized boulders with that on unstable ones confirms that differences in the frequency of disturbances are responsible for the above patterns of species composition. The frequency of disturbance also determines the degree of between—boulder variation in species composition and diversity. Small boulders which are frequently overturned sample the available pool of spores and larvae more often. As a result, a greater number of different species occur as single dominants on these boulders. Boulders with an intermediate probability of being disturbed are most variable in species diversity. Assemblages on these boulders range from being dominated by a single species to being very diverse while most communities on boulders which are frequently or seldom disturbed are strongly dominated. Observations on the local densities of three species of middle successional red algae over two year—long periods indicate that most of these are variable in time. More local populations went extinct or became newly established on boulders than remained constant in size. These species persist globally in the boulder field mosaic by colonizing recent openings created by disturbances. These results lend support to a nonequilibrium view of community structure and, along with other studies suggest that disturbances which open space are necessary for the maintenance of diversity in most communities of sessile organisms.

@article{doi1023071936969,
    author = "Sousa, Wayne P.",
    title = "Disturbance in Marine Intertidal Boulder Fields: The Nonequilibrium Maintenance of Species Diversity",
    year = "1979",
    journal = "Ecology",
    abstract = "The effects of disturbance on local species diversity were investigated in an algaldominated intertidal boulder field in southern California. In this habitat, the major form of disturbance occurs when waves, generated by winter storms, overturn boulders. These natural physical disturbances open space, interrupt successional sequences, and determine local levels of species diversity. Because small boulders are more frequently overturned than larger ones, the plants and sessile animals of boulder fields are distributed in a patchwork of successional stages. Boulders which are subjected to intermediate disturbance frequencies are usually less dominated than those which are very frequently disturbed, and always less dominated than those which are seldon disturbed. In all seasons most small boulders have fewer species than those of intermediate size. Large boulders also usually have fewer species, except in the spring, when defoliation of the algal canopy during the previous winter has opened space for colonization. Species richness on these boulders declines during summer months, and is less than that on boulders of intermediate size in the fall. Small boulders, with a shorter disturbance interval, support only sparse early successional communities of the green alga, Ulva, and barnacles. Large, infrequently disturbed boulders are dominated by the late successional red alga, Gigartina canaliculata. Intermediate—sized boulders support the most diverse communities composed of Ulva, barnacles, several middle successional species of red algae, and Gigartina canaliculata. Comparison of the pattern of succession on experimentally stabilized boulders with that on unstable ones confirms that differences in the frequency of disturbances are responsible for the above patterns of species composition. The frequency of disturbance also determines the degree of between—boulder variation in species composition and diversity. Small boulders which are frequently overturned sample the available pool of spores and larvae more often. As a result, a greater number of different species occur as single dominants on these boulders. Boulders with an intermediate probability of being disturbed are most variable in species diversity. Assemblages on these boulders range from being dominated by a single species to being very diverse while most communities on boulders which are frequently or seldom disturbed are strongly dominated. Observations on the local densities of three species of middle successional red algae over two year—long periods indicate that most of these are variable in time. More local populations went extinct or became newly established on boulders than remained constant in size. These species persist globally in the boulder field mosaic by colonizing recent openings created by disturbances. These results lend support to a nonequilibrium view of community structure and, along with other studies suggest that disturbances which open space are necessary for the maintenance of diversity in most communities of sessile organisms.",
    url = "https://doi.org/10.2307/1936969",
    doi = "10.2307/1936969",
    openalex = "W2104969881",
    references = "dayton1971competition, doi101086282400, doi101086282477, doi101086282541, doi101086283381, doi101093biomet3812196, doi101126science185414527, doi101126science19943351302, doi1015159781400881376, doi1023071268795, doi1023071933500, doi1023071942223, doi1023071942484, doi1023071942565, openalexw1500291103, openalexw2418669733"
}

Mechanisms of ecological succession were investigated by field experiments in a rocky intertidal algal community in southern California. The study site was algal—dominated boulder field in the low intertidal zone. The major form of natural disturbance which clears space in this system is the overturning of boulders by wave action. Algal populations recolonize cleared surfaces either through vegetative regrowth of surviving individuals or by recruitment from spores. Boulders which are experimentally cleared and concrete blocks are colonized within the first month by a mat of the green alga, Ulva. In the fall and winter of the first year after clearing, several species of perennial red algae including Gelidium coulteri, Gigartina leptorhynchos, Rhodoglossum affine, and Gigartina canaliculata colonize the surface. If there is no intervening disturbance, Gigartina canaliculata gradually dominates the community holding 60—90% of the cover after a period of 2 to 3 years. If undisturbed, this monoculture persists through vegetative reproduction, resisting invasion by all other species. During succession diversity increases initially as species colonize a bare surface but declines later as one species monopolizes the space. Several contemporary theories concerning the mechanisms of ecological succession were tested. The early successional alga, Ulva, was found to inhibit the recruitment of perennial red algae. This competition for settling space is an important feature of the successional process. Ulva is the best competitor for this space; it reproduces throughout the year and quickly becomes established on newly cleared substrates. As long as these early colonists remain healthy and undamaged, they preempt colonization by perennial red algae which have highly seasonal recruitment and slower growth. Selective grazing on Ulva by the crab, Pachygrapsus crassipes, breaks this inhibition and accelerates succession to a community of long—lived red algae. Grazing by small molluscs, especially limpets, has no long—term effect on the successional sequence. Their grazing temporarily enhances the recruitment of the barnacle, Chthamalus fissus, by clearing space in the mat of algal sporelings and diatoms which develops on recently denuded rock surfaces. Where locally abundant, middle successional red algae also slow the invasion and growth of the late successional dominant, Gigartina canaliculata. This alga replaces middle successional species because it is less susceptible to damage by desiccation and overgrowth by epiphytes. The results of this study do not support either the classical facilitation model or the tolerance (competitive) model of ecological succession. Once early colonists secure the available space/light, they resist rather than facilitate the invasion of subsequent colonists. Early colonists are not killed by direct interference competition with late successional species which grow up through their canopy; rather, early colonists can successfully inhibit the recruitment and growth of these species. Successional sequences occur because species which dominate early in a succession are more susceptible to the rigors of the physical environment and to attacks by natural enemies than late successional species. Late species colonize and grow to maturity when early species are killed and space is opened. Only late in a successional sequence, when large clearings become a mosaic of small openings, does direct competition with surrounding adult plants of late successional species contribute to the decline in cover of the remaining early species. Studies of succession in a number of terrestrial and marine communities lend support to this inhibition model.

@article{doi1023071942484,
    author = "Sousa, Wayne P.",
    title = "Experimental Investigations of Disturbance and Ecological Succession in a Rocky Intertidal Algal Community",
    year = "1979",
    journal = "Ecological Monographs",
    abstract = "Mechanisms of ecological succession were investigated by field experiments in a rocky intertidal algal community in southern California. The study site was algal—dominated boulder field in the low intertidal zone. The major form of natural disturbance which clears space in this system is the overturning of boulders by wave action. Algal populations recolonize cleared surfaces either through vegetative regrowth of surviving individuals or by recruitment from spores. Boulders which are experimentally cleared and concrete blocks are colonized within the first month by a mat of the green alga, Ulva. In the fall and winter of the first year after clearing, several species of perennial red algae including Gelidium coulteri, Gigartina leptorhynchos, Rhodoglossum affine, and Gigartina canaliculata colonize the surface. If there is no intervening disturbance, Gigartina canaliculata gradually dominates the community holding 60—90\% of the cover after a period of 2 to 3 years. If undisturbed, this monoculture persists through vegetative reproduction, resisting invasion by all other species. During succession diversity increases initially as species colonize a bare surface but declines later as one species monopolizes the space. Several contemporary theories concerning the mechanisms of ecological succession were tested. The early successional alga, Ulva, was found to inhibit the recruitment of perennial red algae. This competition for settling space is an important feature of the successional process. Ulva is the best competitor for this space; it reproduces throughout the year and quickly becomes established on newly cleared substrates. As long as these early colonists remain healthy and undamaged, they preempt colonization by perennial red algae which have highly seasonal recruitment and slower growth. Selective grazing on Ulva by the crab, Pachygrapsus crassipes, breaks this inhibition and accelerates succession to a community of long—lived red algae. Grazing by small molluscs, especially limpets, has no long—term effect on the successional sequence. Their grazing temporarily enhances the recruitment of the barnacle, Chthamalus fissus, by clearing space in the mat of algal sporelings and diatoms which develops on recently denuded rock surfaces. Where locally abundant, middle successional red algae also slow the invasion and growth of the late successional dominant, Gigartina canaliculata. This alga replaces middle successional species because it is less susceptible to damage by desiccation and overgrowth by epiphytes. The results of this study do not support either the classical facilitation model or the tolerance (competitive) model of ecological succession. Once early colonists secure the available space/light, they resist rather than facilitate the invasion of subsequent colonists. Early colonists are not killed by direct interference competition with late successional species which grow up through their canopy; rather, early colonists can successfully inhibit the recruitment and growth of these species. Successional sequences occur because species which dominate early in a succession are more susceptible to the rigors of the physical environment and to attacks by natural enemies than late successional species. Late species colonize and grow to maturity when early species are killed and space is opened. Only late in a successional sequence, when large clearings become a mosaic of small openings, does direct competition with surrounding adult plants of late successional species contribute to the decline in cover of the remaining early species. Studies of succession in a number of terrestrial and marine communities lend support to this inhibition model.",
    url = "https://doi.org/10.2307/1942484",
    doi = "10.2307/1942484",
    openalex = "W2081634090",
    references = "dayton1971competition, doi101007bf00275587, doi101007bf00345739, doi101073pnas7172744, doi101086283241, doi101086409052, doi101126science1643877262, doi101201b1756026, doi1023071933500, doi1023071942223, doi1023071942321, doi1023071942565, doi1023072257643, doi1023072420377"
}

In the northeastern Pacific, intertidal zones of the most wave-beaten shores receive more energy from breaking waves than from the sun. Despite severe mortality from winter storms, communities at some wave-beaten sites produce an extraordinary quantity of dry matter per unit area of shore per year. At wave-beaten sites of Tatoosh Island, WA, sea palms, Postelsia palmaeformis, can produce > 10 kg of dry matter, or 1.5 x 10(8) J, per m(2) in a good year. Extraordinarily productive organisms such as Postelsia are restricted to wave-beaten sites. Intertidal organisms cannot transform wave energy into chemical energy, as photosynthetic plants transform solar energy, nor can intertidal organisms "harness" wave energy. Nonetheless, wave energy enhances the productivity of intertidal organisms. On exposed shores, waves increase the capacity of resident algae to acquire nutrients and use sunlight, augment the competitive ability of productive organisms, and protect intertidal residents by knocking away their enemies or preventing them from feeding.

@article{doi101073pnas8451314,
    author = "Leigh, Egbert Giles and Paine, Robert T. and Quinn, James and Suchanek, Thomas H.",
    title = "Wave energy and intertidal productivity",
    year = "1987",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = {In the northeastern Pacific, intertidal zones of the most wave-beaten shores receive more energy from breaking waves than from the sun. Despite severe mortality from winter storms, communities at some wave-beaten sites produce an extraordinary quantity of dry matter per unit area of shore per year. At wave-beaten sites of Tatoosh Island, WA, sea palms, Postelsia palmaeformis, can produce > 10 kg of dry matter, or 1.5 x 10(8) J, per m(2) in a good year. Extraordinarily productive organisms such as Postelsia are restricted to wave-beaten sites. Intertidal organisms cannot transform wave energy into chemical energy, as photosynthetic plants transform solar energy, nor can intertidal organisms "harness" wave energy. Nonetheless, wave energy enhances the productivity of intertidal organisms. On exposed shores, waves increase the capacity of resident algae to acquire nutrients and use sunlight, augment the competitive ability of productive organisms, and protect intertidal residents by knocking away their enemies or preventing them from feeding.},
    url = "https://doi.org/10.1073/pnas.84.5.1314",
    doi = "10.1073/pnas.84.5.1314",
    openalex = "W2076581086",
    references = "doi1010160014579383800982, doi1010160378112779900562, doi101126science1824116975, doi101126science1944268937, doi101126science2054407685, doi101126science2304728895, doi102307213225, doi1023074109478, doi105962bhltitle59008"
}

@article{dittmann1990mussel,
    author = "Dittmann, Sabine",
    title = "Mussel beds — amensalism or amelioration for intertidal fauna?",
    year = "1990",
    journal = "Helgoländer Meeresuntersuchungen",
    url = "https://doi.org/10.1007/bf02365471",
    doi = "10.1007/bf02365471",
    number = "3-4",
    openalex = "W1972342618",
    pages = "335-352",
    volume = "44",
    references = "doi1010079783642704956, doi1010079783662057483, doi101007bf00397431, doi1010160022519366900130, doi101357002224020834162167, doi1023071934145, doi1029830350340121u110, openalexw1556017617, openalexw2560743082, openalexw2611775752"
}

You would be hard pressed to find a paleontological study that did not have some taphonomic component to it. In fact, has been criticized for being so broad a field of study as to render term taphonomy itself trifling. Yet, if we are interested in restor[ing] flesh and blood of fossil (p. 22), it is imperative to consider multifarious factors affecting processes of fossilization. Behrensmeyer and Kidwell (1985, p. 105) provided a modern working definition of taphonomy: the study of processes of preservation and how they affect information in fossil Their seminal review of field was coincident with a dramatic increase in research that took place in 1980's (Fig. 1). As with any field experiencing a renaissance, spawned a wealth of new research and literature. However, it now appears that growth in research experienced in mid-1980's has leveled off (Fig. 1). This would indicate that time is ripe for a synthesis. The Donovan book provides such a synthesis and is an excellent introduction to taphonomy. It includes a variety of topics ranging from theoretical considerations in estimating completeness of fossil record, to a chapter entitled: Bones as stones: contribution of vertebrate remains to lithologic The first three chapters cover: history of taphonomy; taphonomic processes and biases; and completeness of fossil record. These are provocative, well written and should be of general interest to all paleontologists. Cadee provides a scholarly account of development of as a distinct discipline. It is best work on this topic that I have read. His command of literature (well beyond modern works published in English) enables him to render a truly eclectic overview of field. This chapter would make an excellent reading assignment in any university-level paleontology course. The Parsons and Brett chapter on taphonomic processes and biases contains three sections: live/dead assemblage comparisons; taphonomic processes and properties; and taphofacies analysis. While they provide thorough reviews of these topics, they do not completely integrate these sections and show connections among these subdisciplines. Nonetheless, I wholly agree with their assessment that taphonomists are much

@article{doi1023073514978,
    author = "Russell, Michael P. and Donovan, Stephen K.",
    title = "The Processes of Fossilization",
    year = "1992",
    journal = "Palaios",
    abstract = "You would be hard pressed to find a paleontological study that did not have some taphonomic component to it. In fact, has been criticized for being so broad a field of study as to render term taphonomy itself trifling. Yet, if we are interested in restor[ing] flesh and blood of fossil (p. 22), it is imperative to consider multifarious factors affecting processes of fossilization. Behrensmeyer and Kidwell (1985, p. 105) provided a modern working definition of taphonomy: the study of processes of preservation and how they affect information in fossil Their seminal review of field was coincident with a dramatic increase in research that took place in 1980's (Fig. 1). As with any field experiencing a renaissance, spawned a wealth of new research and literature. However, it now appears that growth in research experienced in mid-1980's has leveled off (Fig. 1). This would indicate that time is ripe for a synthesis. The Donovan book provides such a synthesis and is an excellent introduction to taphonomy. It includes a variety of topics ranging from theoretical considerations in estimating completeness of fossil record, to a chapter entitled: Bones as stones: contribution of vertebrate remains to lithologic The first three chapters cover: history of taphonomy; taphonomic processes and biases; and completeness of fossil record. These are provocative, well written and should be of general interest to all paleontologists. Cadee provides a scholarly account of development of as a distinct discipline. It is best work on this topic that I have read. His command of literature (well beyond modern works published in English) enables him to render a truly eclectic overview of field. This chapter would make an excellent reading assignment in any university-level paleontology course. The Parsons and Brett chapter on taphonomic processes and biases contains three sections: live/dead assemblage comparisons; taphonomic processes and properties; and taphofacies analysis. While they provide thorough reviews of these topics, they do not completely integrate these sections and show connections among these subdisciplines. Nonetheless, I wholly agree with their assessment that taphonomists are much",
    url = "https://doi.org/10.2307/3514978",
    doi = "10.2307/3514978",
    openalex = "W2048209392"
}

Some of the most remarkable fossils preserve cellular details of soft tissues. In many of these, the tissues have been replaced by calcium phosphate. This process has been assumed to require elevated concentrations of phosphate in sediment pore waters. In decay experiments modern shrimps became partially mineralized in amorphous calcium phosphate, preserving cellular details of muscle tissue, particularly in a system closed to oxygen. The source for the formation of calcium phosphate was the shrimp itself. Mineralization, which was accompanied by a drop in pH, commenced within 2 weeks and increased in extent for at least 4 to 8 weeks. This mechanism halts the normal loss of detail of soft-tissue morphology before fossilization. Similar closed conditions would prevail where organisms are rapidly overgrown by microbial mats.

@article{doi101126science25951001439,
    author = "Briggs, Derek E. G. and Kear, Amanda J.",
    title = "Fossilization of Soft Tissue in the Laboratory",
    year = "1993",
    journal = "Science",
    abstract = "Some of the most remarkable fossils preserve cellular details of soft tissues. In many of these, the tissues have been replaced by calcium phosphate. This process has been assumed to require elevated concentrations of phosphate in sediment pore waters. In decay experiments modern shrimps became partially mineralized in amorphous calcium phosphate, preserving cellular details of muscle tissue, particularly in a system closed to oxygen. The source for the formation of calcium phosphate was the shrimp itself. Mineralization, which was accompanied by a drop in pH, commenced within 2 weeks and increased in extent for at least 4 to 8 weeks. This mechanism halts the normal loss of detail of soft-tissue morphology before fossilization. Similar closed conditions would prevail where organisms are rapidly overgrown by microbial mats.",
    url = "https://doi.org/10.1126/science.259.5100.1439",
    doi = "10.1126/science.259.5100.1439",
    openalex = "W2052326945",
    references = "allison1988the, doi1010160025322788900928, doi101017s009483730001188x, doi101017s0094837300012343, doi101038340138a0, doi101038346171a0, doi101099002212871351175, doi101126science1593811195, doi101306d42676db2b2611d78648000102c1865d, doi10310910520298309066811, openalexw114633828"
}

What is the likelihood that biotic associations from a contemporary rocky-shore setting may find their way into the geologic record? Previous studies on fossilization potential have analyzed recent faunas on an inventory basis. This study considers the fate of intact biotic associations arrayed among 30 macrospecies of invertebrates and algae on a small island in Concepcion Bay, Baja California Sur, Mexico. Field data collected from a network of 15 transects and 66 census stations were subjected to Rand Q-mode analyses in order to establish and map windward and leeward facies on the island. Nearly all the species forming intertidal associations have hard parts which insure a high probability of fossilization, but 37—63 % of the species in the adjoining shallow-subtidal zone have no chance or poor chances of fossilization. Species of Sporolithon and allied red coralline algae in the intertidal and shallow subtidal zones play a key role by encrusting large surfaces and binding in situ associated fauna such as barnacles and the bivalve Area pacifica. Burial of leeward rocky shores is already being effected due to the in-filling of a lagoon; future burial of windward rocky shores is possible due to the faulted structure of Concepcion Bay. Similar physical scenarios are known from the geologic record and they should afford a rich source of rocky-shore fossils for the study of community evolution.

@article{openalexw2152529191,
    author = "Hayes, Marshall L. and Johnson, Markes E. and Fox, William T.",
    title = "Rocky-Shore Biotic Associations and Their Fossilization Potential: Isla Requeson (Baja California Sur, Mexico)",
    year = "1993",
    journal = "Journal of Coastal Research",
    abstract = "What is the likelihood that biotic associations from a contemporary rocky-shore setting may find their way into the geologic record? Previous studies on fossilization potential have analyzed recent faunas on an inventory basis. This study considers the fate of intact biotic associations arrayed among 30 macrospecies of invertebrates and algae on a small island in Concepcion Bay, Baja California Sur, Mexico. Field data collected from a network of 15 transects and 66 census stations were subjected to Rand Q-mode analyses in order to establish and map windward and leeward facies on the island. Nearly all the species forming intertidal associations have hard parts which insure a high probability of fossilization, but 37—63 \% of the species in the adjoining shallow-subtidal zone have no chance or poor chances of fossilization. Species of Sporolithon and allied red coralline algae in the intertidal and shallow subtidal zones play a key role by encrusting large surfaces and binding in situ associated fauna such as barnacles and the bivalve Area pacifica. Burial of leeward rocky shores is already being effected due to the in-filling of a lagoon; future burial of windward rocky shores is possible due to the faulted structure of Concepcion Bay. Similar physical scenarios are known from the geologic record and they should afford a rich source of rocky-shore fossils for the study of community evolution.",
    url = "https://openalex.org/W2152529191",
    openalex = "W2152529191",
    references = "doi101007978364270831222, doi101016003707388890019x, doi1010160037073888900760, doi101073pnas8451314, doi101086629241, doi101130001676061968791315tailif20co2, doi101306ad46135916f711d78645000102c1865d, doi101306m47542c26, doi105860choice266280, openalexw615408771"
}

The usefulness and generality of the keystone species concept has recently been questioned. We investigated variation in interaction strength between the original keystone predator, the seastar Pisaster ochraceus, and its primary prey, mussels (Mytilus californianus and M. trossulus). The study was prompted by differences in community structure at two low zone sites along the central Oregon coast, Boiler Bay (BB) and Strawberry Hill (SH). Predators, especially seastars, were larger and more abundant at SH than at BB. Further, sessile animals were more abundant and macrophytes were less abundant at SH. Predators were more abundant at wave—exposed sites at both sites, and at SH, sessile invertebrates were more abundant at the wave—exposed location and sand cover was high at the wave—protected location. To test the hypothesis that variation in predation strength explained some of these differences, we examined the seastar—mussel interaction at locations with high and low wave exposure at both sites. Predation intensity was quantified by determining the survival of mussels in clumps (50 mussels per clump, shell length 4—7 cm) transplanted to large plots (18—163 m 2) with or without seastars in the low intertidal zone. Predation effects were quantified by determining prey recolonization rates in marked quadrats in the same large plots. Spatial variation in interaction strength was quantified by examining predation at scales of metres (among transplants within plots), 10's of metres (between replicate plots within each exposure at each site), 100's of metres (between wave exposures within locations), and 10 000's of metres (between sites). Temporal variation was evaluated by performing the experiments in 1990 and 1991. The relation between prey (mussel) recruitment and growth to differences in community structure was evaluated by quantifying recruitment density in plastic mesh balls (collectors) and growth of individually marked transplanted mussels, respectively, at each site ° exposure ° tide level combination each month for 4 yr. Predation intensity varied greatly at all spatial scales. At the two largest spatial scales (10's of kilometres, 100's of metres), differences in both survival of transplanted mussels and prey recolonization depended on variation in seastar abundance with site, wave exposure, prey recruitment and growth, and at SH protected, the extent of sand burial. Variation at the two smallest scales (metres, 10's of metres) was high when seastars were scarce and low when seastars were abundant. Transplanted mussels suffered 100% mortality in 2 wk at wave—exposed SH, but took >52 wk at wave—protected BB. Seastar effects on prey recolonization were detected only at the SH wave—exposed site. Here, where prey recruitment and growth were unusually high, the mussel M. trossulus invaded and dominated space within 9 mo. After 14 mo, whelks, which increased in both size and abundance in the absence of Pisaster, arrested this increase in mussel abundance. Similar changes did not occur at other site ° exposure combinations, evidently because prey recruitment was low and possibly also due to whelk predation on juveniles. Longer term results indicate that, as in Washington state, seastars prevent large adult M. californianus from invading lower intertidal regions, but only at wave—exposed, not wave—protected sites. Thus, three distinct predation regimes were observed: (1) strong keystone predation by seastars at wave—exposed headlands; (2) less—strong diffuse predation by seastars, whelks, and possibly other predators at a wave—protected cove, and (3) weak predation at a wave—protected site buried regularly by sand. Comparable experimental results at four wave—exposed headlands (our two in Oregon and two others in Washington), and similarities between these and communities on other West Coast headlands suggest keystone predation occurs broadly in this system. Results in wave—protected habitats, however, suggest it is not universal. In Oregon, keystone predation was evidently contingent on conditions of high prey production (i.e., recruitment and growth), while diffuse predation occurred when prey production was low, and weak predation occurred when environmental stress was high. Combining our results with examples from other marine and non—marine habitats suggests a need to consider a broader range of models than just keystone predation. The predictive and explanatory value of an expanded set of models depends on identifying factors distinguishing them. Although evidence is limited, a survey of 17 examples suggests (1) keystone predation is evidently not distinguished from diffuse predation by any of 11 previously proposed differences, but (2) may be distinguished by rates of prey production. Further, (3) differential predation on competitively dominant prey does not distinguish keystone from nonkeystone systems, since this interaction occurs in both types of community. Instead, differential predation on dominant prey evidently distinguishes strong—from weak—predation communities. While the keystone predation concept has been and will continue to be useful, a broadened focus on testing and developing more general models of community regulation is needed.

@article{doi1023072937163,
    author = "Menge, Bruce A. and Berlow, Eric L. and Blanchette, Carol A. and Navarrete, Sérgio A. and Yamada, Sylvia Behrens",
    title = "The Keystone Species Concept: Variation in Interaction Strength in a Rocky Intertidal Habitat",
    year = "1994",
    journal = "Ecological Monographs",
    abstract = "The usefulness and generality of the keystone species concept has recently been questioned. We investigated variation in interaction strength between the original keystone predator, the seastar Pisaster ochraceus, and its primary prey, mussels (Mytilus californianus and M. trossulus). The study was prompted by differences in community structure at two low zone sites along the central Oregon coast, Boiler Bay (BB) and Strawberry Hill (SH). Predators, especially seastars, were larger and more abundant at SH than at BB. Further, sessile animals were more abundant and macrophytes were less abundant at SH. Predators were more abundant at wave—exposed sites at both sites, and at SH, sessile invertebrates were more abundant at the wave—exposed location and sand cover was high at the wave—protected location. To test the hypothesis that variation in predation strength explained some of these differences, we examined the seastar—mussel interaction at locations with high and low wave exposure at both sites. Predation intensity was quantified by determining the survival of mussels in clumps (50 mussels per clump, shell length 4—7 cm) transplanted to large plots (18—163 m 2) with or without seastars in the low intertidal zone. Predation effects were quantified by determining prey recolonization rates in marked quadrats in the same large plots. Spatial variation in interaction strength was quantified by examining predation at scales of metres (among transplants within plots), 10's of metres (between replicate plots within each exposure at each site), 100's of metres (between wave exposures within locations), and 10 000's of metres (between sites). Temporal variation was evaluated by performing the experiments in 1990 and 1991. The relation between prey (mussel) recruitment and growth to differences in community structure was evaluated by quantifying recruitment density in plastic mesh balls (collectors) and growth of individually marked transplanted mussels, respectively, at each site ° exposure ° tide level combination each month for 4 yr. Predation intensity varied greatly at all spatial scales. At the two largest spatial scales (10's of kilometres, 100's of metres), differences in both survival of transplanted mussels and prey recolonization depended on variation in seastar abundance with site, wave exposure, prey recruitment and growth, and at SH protected, the extent of sand burial. Variation at the two smallest scales (metres, 10's of metres) was high when seastars were scarce and low when seastars were abundant. Transplanted mussels suffered 100\% mortality in 2 wk at wave—exposed SH, but took >52 wk at wave—protected BB. Seastar effects on prey recolonization were detected only at the SH wave—exposed site. Here, where prey recruitment and growth were unusually high, the mussel M. trossulus invaded and dominated space within 9 mo. After 14 mo, whelks, which increased in both size and abundance in the absence of Pisaster, arrested this increase in mussel abundance. Similar changes did not occur at other site ° exposure combinations, evidently because prey recruitment was low and possibly also due to whelk predation on juveniles. Longer term results indicate that, as in Washington state, seastars prevent large adult M. californianus from invading lower intertidal regions, but only at wave—exposed, not wave—protected sites. Thus, three distinct predation regimes were observed: (1) strong keystone predation by seastars at wave—exposed headlands; (2) less—strong diffuse predation by seastars, whelks, and possibly other predators at a wave—protected cove, and (3) weak predation at a wave—protected site buried regularly by sand. Comparable experimental results at four wave—exposed headlands (our two in Oregon and two others in Washington), and similarities between these and communities on other West Coast headlands suggest keystone predation occurs broadly in this system. Results in wave—protected habitats, however, suggest it is not universal. In Oregon, keystone predation was evidently contingent on conditions of high prey production (i.e., recruitment and growth), while diffuse predation occurred when prey production was low, and weak predation occurred when environmental stress was high. Combining our results with examples from other marine and non—marine habitats suggests a need to consider a broader range of models than just keystone predation. The predictive and explanatory value of an expanded set of models depends on identifying factors distinguishing them. Although evidence is limited, a survey of 17 examples suggests (1) keystone predation is evidently not distinguished from diffuse predation by any of 11 previously proposed differences, but (2) may be distinguished by rates of prey production. Further, (3) differential predation on competitively dominant prey does not distinguish keystone from nonkeystone systems, since this interaction occurs in both types of community. Instead, differential predation on dominant prey evidently distinguishes strong—from weak—predation communities. While the keystone predation concept has been and will continue to be useful, a broadened focus on testing and developing more general models of community regulation is needed.",
    url = "https://doi.org/10.2307/2937163",
    doi = "10.2307/2937163",
    openalex = "W2063150254",
    references = "doi1023071935526, doi1023071942565"
}

Insight into the dependence of benthic communities on biological and physical processes in nearshore pelagic environments, long considered a "black box," has eluded ecologists. In rocky intertidal communities at Oregon coastal sites 80 km apart, differences in abundance of sessile invertebrates, herbivores, carnivores, and macrophytes in the low zone were not readily explained by local scale differences in hydrodynamic or physical conditions (wave forces, surge flow, or air temperature during low tide). Field experiments employing predator and herbivore manipulations and prey transplants suggested top-down (predation, grazing) processes varied positively with bottom-up processes (growth of filter-feeders, prey recruitment), but the basis for these differences was unknown. Shore-based sampling revealed that between-site differences were associated with nearshore oceanographic conditions, including phytoplankton concentration and productivity, particulates, and water temperature during upwelling. Further, samples taken at 19 sites along 380 km of coastline suggested that the differences documented between two sites reflect broader scale gradients of phytoplankton concentration. Among several alternative explanations, a coastal hydrodynamics hypothesis, reflecting mesoscale (tens to hundreds of kilometers) variation in the interaction between offshore currents and winds and continental shelf bathymetry, was inferred to be the primary underlying cause. Satellite imagery and offshore chlorophyll-a samples are consistent with the postulated mechanism. Our results suggest that benthic community dynamics can be coupled to pelagic ecosystems by both trophic and transport linkages.

@article{doi101073pnas942614530,
    author = "Menge, Bruce A. and Daley, Bryon A. and Wheeler, Patricia A. and Dahlhoff, Elizabeth P. and Sanford, Eric and Strub, P. Ted",
    title = "Benthic–pelagic links and rocky intertidal communities: Bottom-up effects on top-down control?",
    year = "1997",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = {Insight into the dependence of benthic communities on biological and physical processes in nearshore pelagic environments, long considered a "black box," has eluded ecologists. In rocky intertidal communities at Oregon coastal sites 80 km apart, differences in abundance of sessile invertebrates, herbivores, carnivores, and macrophytes in the low zone were not readily explained by local scale differences in hydrodynamic or physical conditions (wave forces, surge flow, or air temperature during low tide). Field experiments employing predator and herbivore manipulations and prey transplants suggested top-down (predation, grazing) processes varied positively with bottom-up processes (growth of filter-feeders, prey recruitment), but the basis for these differences was unknown. Shore-based sampling revealed that between-site differences were associated with nearshore oceanographic conditions, including phytoplankton concentration and productivity, particulates, and water temperature during upwelling. Further, samples taken at 19 sites along 380 km of coastline suggested that the differences documented between two sites reflect broader scale gradients of phytoplankton concentration. Among several alternative explanations, a coastal hydrodynamics hypothesis, reflecting mesoscale (tens to hundreds of kilometers) variation in the interaction between offshore currents and winds and continental shelf bathymetry, was inferred to be the primary underlying cause. Satellite imagery and offshore chlorophyll-a samples are consistent with the postulated mechanism. Our results suggest that benthic community dynamics can be coupled to pelagic ecosystems by both trophic and transport linkages.},
    url = "https://doi.org/10.1073/pnas.94.26.14530",
    doi = "10.1073/pnas.94.26.14530",
    openalex = "W2020100924",
    references = "doi101073pnas8451314, doi1015159780295743240"
}

Changes in the abundance of macroinvertebrate species documented in a rocky intertidal community between surveys in 1931–1933 and 1993–1996 are consistent with the predicted effects of recent climate warming. We resampled 57 0.84-m2 plots of an intertidal transect first surveyed by W. G. Hewatt at Hopkins Marine Station (HMS), Pacific Grove, California, between 1931 and 1933. Replicating precisely the location of the plots and methodology used by Hewatt, we documented changes in the abundances of 46 invertebrate species, indicating that this intertidal community changed significantly during the 60 yr between surveys. Changes in abundance were related to geographic ranges of species. Most southern species (10 of 11) increased in abundance, whereas most northern species (5 of 7) decreased. Cosmopolitan species showed no clear trend, with 12 increasing and 16 decreasing. Although Hewatt did not record algal species as thoroughly as invertebrates, we were able to document a massive decline in cover of Pelvetia compressa, a cosmopolitan fucoid alga that is typically more common in the southern part of its range. Shoreline ocean temperature, taken daily at HMS, warmed by 0.79°C during this 60-yr period, with average summer temperatures up to 1.94°C warmer in the 13 yr preceding our study than in the 13 yr preceding Hewatt's. The hypothesis that climatic warming drove the observed range-related community shifts is supported further by historical records and data from other investigators. Several alternative hypotheses to explain changes in the invertebrate community at HMS, including habitat changes, anthropogenic effects, indirect biological interactions, El Niño–Southern Oscillation (ENSO) events, and upwelling are considered to be less important than climate change. Changes in species' abundances over a short period (3 yr) were relatively small compared to large species shifts over 60 yr and were unrelated to geographic range of the species, indicating that short-term population fluctuations play a relatively minor role in the long-term community changes that we observed.

@article{doi1018900012961519990690465crciai20co2,
    author = "Sagarin, Raphael D. and Barry, James and Gilman, Sarah E. and Baxter, Charles H.",
    title = "CLIMATE-RELATED CHANGE IN AN INTERTIDAL COMMUNITY OVER SHORT AND LONG TIME SCALES",
    year = "1999",
    journal = "Ecological Monographs",
    abstract = "Changes in the abundance of macroinvertebrate species documented in a rocky intertidal community between surveys in 1931–1933 and 1993–1996 are consistent with the predicted effects of recent climate warming. We resampled 57 0.84-m2 plots of an intertidal transect first surveyed by W. G. Hewatt at Hopkins Marine Station (HMS), Pacific Grove, California, between 1931 and 1933. Replicating precisely the location of the plots and methodology used by Hewatt, we documented changes in the abundances of 46 invertebrate species, indicating that this intertidal community changed significantly during the 60 yr between surveys. Changes in abundance were related to geographic ranges of species. Most southern species (10 of 11) increased in abundance, whereas most northern species (5 of 7) decreased. Cosmopolitan species showed no clear trend, with 12 increasing and 16 decreasing. Although Hewatt did not record algal species as thoroughly as invertebrates, we were able to document a massive decline in cover of Pelvetia compressa, a cosmopolitan fucoid alga that is typically more common in the southern part of its range. Shoreline ocean temperature, taken daily at HMS, warmed by 0.79°C during this 60-yr period, with average summer temperatures up to 1.94°C warmer in the 13 yr preceding our study than in the 13 yr preceding Hewatt's. The hypothesis that climatic warming drove the observed range-related community shifts is supported further by historical records and data from other investigators. Several alternative hypotheses to explain changes in the invertebrate community at HMS, including habitat changes, anthropogenic effects, indirect biological interactions, El Niño–Southern Oscillation (ENSO) events, and upwelling are considered to be less important than climate change. Changes in species' abundances over a short period (3 yr) were relatively small compared to large species shifts over 60 yr and were unrelated to geographic range of the species, indicating that short-term population fluctuations play a relatively minor role in the long-term community changes that we observed.",
    url = "https://doi.org/10.1890/0012-9615(1999)069[0465:crciai]2.0.co;2",
    doi = "10.1890/0012-9615(1999)069[0465:crciai]2.0.co;2",
    openalex = "W2145529319",
    references = "doi101017s0025315400000102, doi1015159780295743240, openalexw615408771"
}

Skeletal encrusters and carbonate hardgrounds are rare in siliciclastic sands and gravels because of high levels of abrasion and sediment movement. An exception to this is the Maastrichtian Qahlah Formation of the Oman Mountains, a sequence of coarse siliciclastic sediments deposited on a shallow marine shelf above wavebase and at an equatorial palaeolatitude. This unit contains intercalated carbonate hardgrounds and other hard substrates which were encrusted and bored. The hard substrates, comprising carbonate and silicate clasts, calcareous bioclasts (mollusc shells and coral fragments) and wood, supported a diverse encrusting and boring fauna dominated in biomass by the oyster Acutostrea. There are twelve bryozoan species and at least two serpulid worm species, most living cryptically. Other encrusters on exposed surfaces include the agglutinated foraminiferan Placopsilina and several species of colonial corals. Borings in the carbonate clasts and shells are predominantly those of bivalves (Gastrochaenolites), with subsidiary clionid sponge (Entobia) and acrothoracican barnacle (Rogerella) borings. The woodgrounds are thoroughly bored by teredinid bivalves (Teredolites). Of the common substrate types, carbonate hardground clasts support the greatest number of taxa, followed by chert clasts, with limestone rockground pebbles being depauperate. Clast composition and relative stability probably explain these differences. Individual clasts probably had variable and typically long colonisation histories. Detailed palaeoecological interpretation is constrained by taphonomic loss, time‐averaging and clast transportation and reorientation. Evidence from the Qahlah Formation shows that tropical rocky‐shore biotas in the Cretaceous were not impoverished as previously believed.

@article{doi1011111475498300167,
    author = "Wilson, Mark A. and Taylor, Paul D.",
    title = "Palaeocology of Hard Substrate Faunas from the Cretaceous Qahlah Formation of the Oman Mountains",
    year = "2001",
    journal = "Palaeontology",
    abstract = "Skeletal encrusters and carbonate hardgrounds are rare in siliciclastic sands and gravels because of high levels of abrasion and sediment movement. An exception to this is the Maastrichtian Qahlah Formation of the Oman Mountains, a sequence of coarse siliciclastic sediments deposited on a shallow marine shelf above wavebase and at an equatorial palaeolatitude. This unit contains intercalated carbonate hardgrounds and other hard substrates which were encrusted and bored. The hard substrates, comprising carbonate and silicate clasts, calcareous bioclasts (mollusc shells and coral fragments) and wood, supported a diverse encrusting and boring fauna dominated in biomass by the oyster Acutostrea. There are twelve bryozoan species and at least two serpulid worm species, most living cryptically. Other encrusters on exposed surfaces include the agglutinated foraminiferan Placopsilina and several species of colonial corals. Borings in the carbonate clasts and shells are predominantly those of bivalves (Gastrochaenolites), with subsidiary clionid sponge (Entobia) and acrothoracican barnacle (Rogerella) borings. The woodgrounds are thoroughly bored by teredinid bivalves (Teredolites). Of the common substrate types, carbonate hardground clasts support the greatest number of taxa, followed by chert clasts, with limestone rockground pebbles being depauperate. Clast composition and relative stability probably explain these differences. Individual clasts probably had variable and typically long colonisation histories. Detailed palaeoecological interpretation is constrained by taphonomic loss, time‐averaging and clast transportation and reorientation. Evidence from the Qahlah Formation shows that tropical rocky‐shore biotas in the Cretaceous were not impoverished as previously believed.",
    url = "https://doi.org/10.1111/1475-4983.00167",
    doi = "10.1111/1475-4983.00167",
    openalex = "W2064431517",
    references = "doi101086629241"
}

@article{doi101007s1015200100983,
    author = "Thiel, Martín and Ullrich, Niklas",
    title = "Hard rock versus soft bottom: the fauna associated with intertidal mussel beds on hard bottoms along the coast of Chile, and considerations on the functional role of mussel beds",
    year = "2002",
    journal = "Helgoland Marine Research",
    url = "https://doi.org/10.1007/s10152-001-0098-3",
    doi = "10.1007/s10152-001-0098-3",
    openalex = "W1977513585",
    references = "dittmann1990mussel"
}

Santos, A., Mayoral, E.J., da Silva, C.M., Cachão, M., Johnson, M.E. & Baarli, B.G. Miocene intertidal zonation on a volcanically active shoreline: Porto Santo in the Madeira Archipelago, Portugal. Lethaia, Vol. 44, pp. 26–32. Short-term biological colonization of rockgrounds on the basaltic shorelines of oceanic islands has, as yet, been poorly explored. A Miocene sea cliff on Ilhéu de Cima off Porto Santo in the Madeira Archipelago of Portugal provides a case study showing intertidal zonation with two types of barnacles, serpulid worm tubes, two coral species, epifaunal bivalves and the trace fossils of endolithic bivalves. Large barnacles (Balanus sp.) and serpulids are limited to the upper 400 mm of a basalt cliff of 1.6 m in height. Small barnacles, possibly of the same species, extend to the base. The upper half includes the corals Isophyllastrea orbignyana and Tarbellastraea reussiana, to which many small, coral-inhabiting, barnacles (Ceratoconcha costata) are fixed. Borings identified as Gastrochaenolites torpedo appear through the bottom two-thirds of the cliff face. Rarely, Gastrochaenolites lapidicus is exposed in longitudinal section with borings up to 45 mm deep in solid basalt. Epifaunal bivalves, such as Spondylus sp., are limited to a middle zone. Associated with the sea cliff is an outer platform on which a multitude of T. reussiana colonies occur in growth position. The corals exhibit planar erosion over180 m2. The shelf was faulted and cut by a basalt dike prior to the brief recolonization of I. orbignyana, found attached to low fault scarps. Habitation of the sea cliff was facilitated by rising sea level, but abruptly terminated by burial under volcanoclastic ejecta. □Basalt bioerosion, coastal dynamics, Ilhéu de Cima (Porto Santo), Miocene intertidal zonation, volcanogenic perturbations.

@article{doi101111j15023931201000222x,
    author = "Santos, Ana and Mayoral, Eduardo and da Silva, Carlos Marques and Cachão, Mário and Johnson, Markes E. and Baarli, B. Gudveig",
    title = "Miocene intertidal zonation on a volcanically active shoreline: Porto Santo in the Madeira Archipelago, Portugal",
    year = "2010",
    journal = "Lethaia",
    abstract = "Santos, A., Mayoral, E.J., da Silva, C.M., Cachão, M., Johnson, M.E. \& Baarli, B.G. Miocene intertidal zonation on a volcanically active shoreline: Porto Santo in the Madeira Archipelago, Portugal. Lethaia, Vol. 44, pp. 26–32. Short-term biological colonization of rockgrounds on the basaltic shorelines of oceanic islands has, as yet, been poorly explored. A Miocene sea cliff on Ilhéu de Cima off Porto Santo in the Madeira Archipelago of Portugal provides a case study showing intertidal zonation with two types of barnacles, serpulid worm tubes, two coral species, epifaunal bivalves and the trace fossils of endolithic bivalves. Large barnacles (Balanus sp.) and serpulids are limited to the upper 400 mm of a basalt cliff of 1.6 m in height. Small barnacles, possibly of the same species, extend to the base. The upper half includes the corals Isophyllastrea orbignyana and Tarbellastraea reussiana, to which many small, coral-inhabiting, barnacles (Ceratoconcha costata) are fixed. Borings identified as Gastrochaenolites torpedo appear through the bottom two-thirds of the cliff face. Rarely, Gastrochaenolites lapidicus is exposed in longitudinal section with borings up to 45 mm deep in solid basalt. Epifaunal bivalves, such as Spondylus sp., are limited to a middle zone. Associated with the sea cliff is an outer platform on which a multitude of T. reussiana colonies occur in growth position. The corals exhibit planar erosion over180 m2. The shelf was faulted and cut by a basalt dike prior to the brief recolonization of I. orbignyana, found attached to low fault scarps. Habitation of the sea cliff was facilitated by rising sea level, but abruptly terminated by burial under volcanoclastic ejecta. □Basalt bioerosion, coastal dynamics, Ilhéu de Cima (Porto Santo), Miocene intertidal zonation, volcanogenic perturbations.",
    url = "https://doi.org/10.1111/j.1502-3931.2010.00222.x",
    doi = "10.1111/j.1502-3931.2010.00222.x",
    openalex = "W1517958390",
    references = "doi101017cbo9781316143445, doi101139e06045, doi1023073515314"
}

BACKGROUND: Ligia isopods are widely distributed in the Pacific rocky intertidal shores from central California to central Mexico, including the Gulf of California. Yet, their biological characteristics restrict them to complete their life cycles in a very narrow range of the rocky intertidal supralittoral. Herein, we examine phylogeographic patterns of Ligia isopods from 122 localities between central California and central Mexico. We expect to find high levels of allopatric diversity. In addition, we expect the phylogeographic patterns to show signatures of past vicariant events that occurred in this geologically dynamic region. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced two mitochondrial genes (Cytochrome Oxidase I and 16S ribosomal DNA). We conducted Maximum Likelihood and Bayesian phylogenetic analyses. We found many divergent clades that, in general, group according to geography. Some of the most striking features of the Ligia phylogeographic pattern include: (1) deep mid-peninsular phylogeographic breaks on the Pacific and Gulf sides of Baja peninsula; (2) within the Gulf lineages, the northern peninsula is most closely related to the northern mainland, while the southern peninsula is most closely related to the central-southern mainland; and, (3) the southernmost portion of the peninsula (Cape Region) is most closely related to the southernmost portion of mainland. CONCLUSIONS/SIGNIFICANCE: Our results shed light on the phylogenetic relationships of Ligia populations in the study area. This study probably represents the finest-scale phylogeographic examination for any organism to date in this region. Presence of highly divergent lineages suggests multiple Ligia species exist in this region. The phylogeographic patterns of Ligia in the Gulf of California and Baja peninsula are incongruent with a widely accepted vicariant scenario among phylogeographers, but consistent with aspects of alternative geological hypotheses and phylo- and biogeographic patterns of several other taxa. Our findings contribute to the ongoing debate regarding the geological origin of this important biogeographic region.

@article{doi101371journalpone0011633,
    author = "Hurtado, Luis A. and Mateos, Mariana and Santamaria, Carlos A.",
    title = "Phylogeography of Supralittoral Rocky Intertidal Ligia Isopods in the Pacific Region from Central California to Central Mexico",
    year = "2010",
    journal = "PLoS ONE",
    abstract = "BACKGROUND: Ligia isopods are widely distributed in the Pacific rocky intertidal shores from central California to central Mexico, including the Gulf of California. Yet, their biological characteristics restrict them to complete their life cycles in a very narrow range of the rocky intertidal supralittoral. Herein, we examine phylogeographic patterns of Ligia isopods from 122 localities between central California and central Mexico. We expect to find high levels of allopatric diversity. In addition, we expect the phylogeographic patterns to show signatures of past vicariant events that occurred in this geologically dynamic region. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced two mitochondrial genes (Cytochrome Oxidase I and 16S ribosomal DNA). We conducted Maximum Likelihood and Bayesian phylogenetic analyses. We found many divergent clades that, in general, group according to geography. Some of the most striking features of the Ligia phylogeographic pattern include: (1) deep mid-peninsular phylogeographic breaks on the Pacific and Gulf sides of Baja peninsula; (2) within the Gulf lineages, the northern peninsula is most closely related to the northern mainland, while the southern peninsula is most closely related to the central-southern mainland; and, (3) the southernmost portion of the peninsula (Cape Region) is most closely related to the southernmost portion of mainland. CONCLUSIONS/SIGNIFICANCE: Our results shed light on the phylogenetic relationships of Ligia populations in the study area. This study probably represents the finest-scale phylogeographic examination for any organism to date in this region. Presence of highly divergent lineages suggests multiple Ligia species exist in this region. The phylogeographic patterns of Ligia in the Gulf of California and Baja peninsula are incongruent with a widely accepted vicariant scenario among phylogeographers, but consistent with aspects of alternative geological hypotheses and phylo- and biogeographic patterns of several other taxa. Our findings contribute to the ongoing debate regarding the geological origin of this important biogeographic region.",
    url = "https://doi.org/10.1371/journal.pone.0011633",
    doi = "10.1371/journal.pone.0011633",
    openalex = "W1994235932",
    references = "openalexw615408771"
}

The south-eastern coast of Australia is recognised as a climate-change hotspot; warming over the past 50 years has exceeded the global average. The marine fauna in the region is responding to this warming with several subtidal species showing a pole-ward range expansion. We provide the first evidence for a similar response in intertidal invertebrates, on the basis of surveys from the eastern coast of Tasmania in 2007–2008 that replicated a set from the 1950s. Of 29 species used in the analysis, 55% were detected further south than in the 1950s. The average minimum movement of the southern (pole-ward) range edges was 116 km (range 20–250 km), representing a rate of \textasciitilde 29 km per decade for a warming rate of 0.22°C per decade. Barnacles and gastropods showed the greatest range extensions, with one species absent from Tasmania in the 1950s, the giant rock barnacle, Austromegabalanus nigrescens, now recorded widely along the eastern coast of Tasmania. The distance that the southern (pole-ward) range limit moved south for each species was not related to a qualitative dispersal potential index. Local extinction of some species in north-eastern Tasmania may also occur in the coming decades.

@article{pitt2010climatedriven,
    author = "Pitt, Nicole R. and Poloczanska, Elvira S. and Hobday, Alistair J.",
    title = "Climate-driven range changes in Tasmanian intertidal fauna",
    year = "2010",
    journal = "Marine and Freshwater Research",
    abstract = "The south-eastern coast of Australia is recognised as a climate-change hotspot; warming over the past 50 years has exceeded the global average. The marine fauna in the region is responding to this warming with several subtidal species showing a pole-ward range expansion. We provide the first evidence for a similar response in intertidal invertebrates, on the basis of surveys from the eastern coast of Tasmania in 2007–2008 that replicated a set from the 1950s. Of 29 species used in the analysis, 55\% were detected further south than in the 1950s. The average minimum movement of the southern (pole-ward) range edges was 116 km (range 20–250 km), representing a rate of \textasciitilde 29 km per decade for a warming rate of 0.22°C per decade. Barnacles and gastropods showed the greatest range extensions, with one species absent from Tasmania in the 1950s, the giant rock barnacle, Austromegabalanus nigrescens, now recorded widely along the eastern coast of Tasmania. The distance that the southern (pole-ward) range limit moved south for each species was not related to a qualitative dispersal potential index. Local extinction of some species in north-eastern Tasmania may also occur in the coming decades.",
    url = "https://doi.org/10.1071/mf09225",
    doi = "10.1071/mf09225",
    number = "9",
    openalex = "W1988468832",
    pages = "963-970",
    volume = "61",
    references = "doi1010160025326x86902547, doi101038416389a, doi101038nature01286, doi101038nature01333, doi101038nature06937, doi101046j152317392001015002320x, doi101126science1071329, doi101126science1111322, doi1023072879, openalexw1548396839"
}

Significance Divergence time estimation on an absolute timescale requires external calibration information, which typically is derived from the fossil record. The common practice in Bayesian divergence time estimation involves applying calibration densities to individual nodes. Often, these priors are arbitrarily chosen and specified yet have an excessive impact on estimates of absolute time. We introduce the fossilized birth–death process—a fossil calibration method that unifies extinct and extant species with a single macroevolutionary model, eliminating the need for ad hoc calibration priors. Compared with common calibration density approaches, Bayesian inference under this mechanistic model yields more accurate node age estimates while providing a coherent measure of statistical uncertainty. Furthermore, unlike calibration densities, our model accommodates all the reliable fossils for a given phylogenetic dataset.

@article{doi101073pnas1319091111,
    author = "Heath, Tracy A. and Huelsenbeck, John P. and Stadler, Tanja",
    title = "The fossilized birth–death process for coherent calibration of divergence-time estimates",
    year = "2014",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Significance Divergence time estimation on an absolute timescale requires external calibration information, which typically is derived from the fossil record. The common practice in Bayesian divergence time estimation involves applying calibration densities to individual nodes. Often, these priors are arbitrarily chosen and specified yet have an excessive impact on estimates of absolute time. We introduce the fossilized birth–death process—a fossil calibration method that unifies extinct and extant species with a single macroevolutionary model, eliminating the need for ad hoc calibration priors. Compared with common calibration density approaches, Bayesian inference under this mechanistic model yields more accurate node age estimates while providing a coherent measure of statistical uncertainty. Furthermore, unlike calibration densities, our model accommodates all the reliable fossils for a given phylogenetic dataset.",
    url = "https://doi.org/10.1073/pnas.1319091111",
    doi = "10.1073/pnas.1319091111",
    openalex = "W2039879168",
    references = "doi101007bf00160154, doi101007bf01734359, doi101016s0169534703002167, doi10103818872, doi10108010635150290102456, doi101086383584, doi101093bioinformatics178754, doi101093biomet824711, doi101093molbevmsl150, doi101093molbevmss075, doi101093molbevmst010, doi101093sysbiosyr047, doi101093sysbiosyr107, doi101093sysbiosys029, doi101098rspb20120683, doi101111j1469185x201100178x, doi101111j15585646201201723x, doi101126science1101074, doi101371journalpbio0040088, openalexw1593676244"
}

Large-scale gravitational flank collapses of steep volcanic islands are hypothetically capable of triggering megatsunamis with highly catastrophic effects. Yet, evidence for the generation and impact of collapse-triggered megatsunamis and their high run-ups remains scarce or is highly controversial. Therefore, doubts remain on whether island flank failures truly generate enough volume flux to trigger giant tsunamis, leading to diverging opinions concerning the real hazard potential of such collapses. We show that one of the most prominent oceanic volcanoes on Earth-Fogo, in the Cape Verde Islands-catastrophically collapsed and triggered a megatsunami with devastating effects ~73,000 years ago. Our deductions are based on the recent discovery and cosmogenic (3)He dating of tsunamigenic deposits found on nearby Santiago Island, which attest to the impact of this giant tsunami and document wave run-up heights exceeding 270 m. The evidence reported here implies that Fogo's flank failure involved at least one fast and voluminous event that led to a giant tsunami, in contrast to what has been suggested before. Our observations therefore further demonstrate that flank collapses may indeed catastrophically happen and are capable of triggering tsunamis of enormous height and energy, adding to their hazard potential.

@article{doi101126sciadv1500456,
    author = "Ramalho, Ricardo S. and Winckler, Gisela and Madeira, José and Helffrich, George and Hipólito, Ana and Quartau, Rui and Adena, K. and Schaefer, Joerg M.",
    title = "Hazard potential of volcanic flank collapses raised by new megatsunami evidence",
    year = "2015",
    journal = "Science Advances",
    abstract = "Large-scale gravitational flank collapses of steep volcanic islands are hypothetically capable of triggering megatsunamis with highly catastrophic effects. Yet, evidence for the generation and impact of collapse-triggered megatsunamis and their high run-ups remains scarce or is highly controversial. Therefore, doubts remain on whether island flank failures truly generate enough volume flux to trigger giant tsunamis, leading to diverging opinions concerning the real hazard potential of such collapses. We show that one of the most prominent oceanic volcanoes on Earth-Fogo, in the Cape Verde Islands-catastrophically collapsed and triggered a megatsunami with devastating effects \textasciitilde 73,000 years ago. Our deductions are based on the recent discovery and cosmogenic (3)He dating of tsunamigenic deposits found on nearby Santiago Island, which attest to the impact of this giant tsunami and document wave run-up heights exceeding 270 m. The evidence reported here implies that Fogo's flank failure involved at least one fast and voluminous event that led to a giant tsunami, in contrast to what has been suggested before. Our observations therefore further demonstrate that flank collapses may indeed catastrophically happen and are capable of triggering tsunamis of enormous height and energy, adding to their hazard potential.",
    url = "https://doi.org/10.1126/sciadv.1500456",
    doi = "10.1126/sciadv.1500456",
    openalex = "W1914038545"
}

Abstract Global biodiversity patterns in deep time can only be understood fully when the relative preservation potential of each clade is known. The relative preservation potential of marine arthropod clades, a diverse and ecologically important component of modern and past ecosystems, is poorly known. We tackled this issue by carrying out a 205‐day long comprehensive, comparative, taphonomic experiment in a laboratory by scoring up to ten taphonomic characters for multiple specimens of seven crustacean and one chelicerate species (two true crabs, one shrimp, one lobster, one hermit crab, one stomatopod, one barnacle and one horseshoe crab). Although the results are preliminary because we used a single experimental setup and algal growth partially hampered observations, some parts of hermit crabs, stomatopods, swimming crabs and barnacles decayed slowly relative to other parts, implying differential preservation potentials within species, largely consistent with the fossil record of these groups. An inferred parasitic isopod, manifested by a bopyriform swelling within a hermit crab carapace, decayed relatively fast. We found limited variation in the decay rate between conspecifics, and we did not observe size‐related trends in decay rate. Conversely, substantial differences in the decay rate between species were seen after c. 50 days, with shrimps and stomatopods decaying fastest, suggesting a relatively low preservation potential, whereas the lobster, calico crabs, horseshoe crabs and barnacles showed relatively slow decay rates, suggesting a higher preservation potential. These results are supported by two modern and fossil record‐based preservation potential metrics that are significantly correlated to decay rate ranks. Furthermore, we speculate that stemward slippage may not be ubiquitous in marine arthropods. Our results imply that diversity studies of true crabs, lobsters, horseshoe crabs and barnacles are more likely to yield patterns that are closer to their true biodiversity patterns than those for stomatopods, shrimps and hermit crabs.

@article{doi101111pala12314,
    author = "Klompmaker, Adiël A. and Portell, Roger W. and Frick, Michael G.",
    title = "Comparative experimental taphonomy of eight marine arthropods indicates distinct differences in preservation potential",
    year = "2017",
    journal = "Palaeontology",
    abstract = "Abstract Global biodiversity patterns in deep time can only be understood fully when the relative preservation potential of each clade is known. The relative preservation potential of marine arthropod clades, a diverse and ecologically important component of modern and past ecosystems, is poorly known. We tackled this issue by carrying out a 205‐day long comprehensive, comparative, taphonomic experiment in a laboratory by scoring up to ten taphonomic characters for multiple specimens of seven crustacean and one chelicerate species (two true crabs, one shrimp, one lobster, one hermit crab, one stomatopod, one barnacle and one horseshoe crab). Although the results are preliminary because we used a single experimental setup and algal growth partially hampered observations, some parts of hermit crabs, stomatopods, swimming crabs and barnacles decayed slowly relative to other parts, implying differential preservation potentials within species, largely consistent with the fossil record of these groups. An inferred parasitic isopod, manifested by a bopyriform swelling within a hermit crab carapace, decayed relatively fast. We found limited variation in the decay rate between conspecifics, and we did not observe size‐related trends in decay rate. Conversely, substantial differences in the decay rate between species were seen after c. 50 days, with shrimps and stomatopods decaying fastest, suggesting a relatively low preservation potential, whereas the lobster, calico crabs, horseshoe crabs and barnacles showed relatively slow decay rates, suggesting a higher preservation potential. These results are supported by two modern and fossil record‐based preservation potential metrics that are significantly correlated to decay rate ranks. Furthermore, we speculate that stemward slippage may not be ubiquitous in marine arthropods. Our results imply that diversity studies of true crabs, lobsters, horseshoe crabs and barnacles are more likely to yield patterns that are closer to their true biodiversity patterns than those for stomatopods, shrimps and hermit crabs.",
    url = "https://doi.org/10.1111/pala.12314",
    doi = "10.1111/pala.12314",
    openalex = "W2735559830",
    references = "doi101016jpalaeo201402025, doi101111pala12219, vega1999a"
}

Abstract The fossil record provides the only direct record of the history of life, but it is an incomplete one. Discriminating between what is absent and what is simply not preserved is critical to macroevolutionary and macroecological inferences. A comparison of diversity data in over 20,000 modern marine assemblages from the Ocean Biogeographic Information System database (OBIS) with fossil occurrence data from the Paleobiology Database (PBDB) yielded a global assessment of assemblage-level fossilization potential. We used two different metrics, taxon fossilization potential and within-environment fossilization potential, to assess the proportion of taxa in a modern community with PBDB occurrences or with PBDB occurrences in the same environment, respectively. Taxon fossilization potential of marine genera varies between environments, from 34% in shallow and deep water to 44% in coral reefs, 51% on seamounts, and 15% in pelagic assemblages. Within-environment fossilization potential, in contrast, does not exceed 32% (in shallow water), a lower value than that obtained in other studies, and it may be zero (on seamounts and pelagic environments). These differences are mainly a product of representation in the rock record and sampling biases rather than taxon duration.

@article{doi101130g479071,
    author = "Shaw, Jack O. and Briggs, Derek E. G. and Hull, Pincelli M.",
    title = "Fossilization potential of marine assemblages and environments",
    year = "2020",
    journal = "Geology",
    abstract = "Abstract The fossil record provides the only direct record of the history of life, but it is an incomplete one. Discriminating between what is absent and what is simply not preserved is critical to macroevolutionary and macroecological inferences. A comparison of diversity data in over 20,000 modern marine assemblages from the Ocean Biogeographic Information System database (OBIS) with fossil occurrence data from the Paleobiology Database (PBDB) yielded a global assessment of assemblage-level fossilization potential. We used two different metrics, taxon fossilization potential and within-environment fossilization potential, to assess the proportion of taxa in a modern community with PBDB occurrences or with PBDB occurrences in the same environment, respectively. Taxon fossilization potential of marine genera varies between environments, from 34\% in shallow and deep water to 44\% in coral reefs, 51\% on seamounts, and 15\% in pelagic assemblages. Within-environment fossilization potential, in contrast, does not exceed 32\% (in shallow water), a lower value than that obtained in other studies, and it may be zero (on seamounts and pelagic environments). These differences are mainly a product of representation in the rock record and sampling biases rather than taxon duration.",
    url = "https://doi.org/10.1130/g47907.1",
    doi = "10.1130/g47907.1",
    openalex = "W3093620175",
    references = "doi1010160012825272900724, doi101017s000632310000548x, doi101017s0094837300016134, doi10103818872, doi101073pnas0601264103, doi101093nqs9viii207495b, doi101111j150238851991tb00307x, doi101111j150239311977tb00628x, doi101126science1260065, openalexw2152529191, openalexw2754161204"
}