Micropaleophytology

@misc{timofeyev1964about1,
    author = "Timofeyev, B. V. and Bagdasaryan, L. L",
    title = "About the results of micropaleophytological study of oil from East Siberia",
    year = "1964",
    howpublished = "Academy of Sciences of the USSR Reports, v. 154, no. 1, p. 102-103; English translation by American Geological Institute, 1964,Academy of Science, USSR Reports, v.154, p. 22-24",
    note = "talkorigins\_source = {true}; raw\_reference = {Timofeyev, B. V., and Bagdasaryan, L. L., 1964, About the results of micropaleophytological study of oil from East Siberia: Academy of Sciences of the USSR Reports, v. 154, no. 1, p. 102-103; English translation by American Geological Institute, 1964,Academy of Science, USSR Reports, v.154, p. 22-24.}"
}

The Vikulov formation in the Tyumen District of southwestern Siberia consists of incised-valley deposits and shallow-marine delta-front sands, which form oil reservoirs in the area of the Krasnoleninsk dome. Reservoir quality varies considerably depending on the depositional facies. In places, high permeability channels and bars were deposited, whereas the more distal sands have much lower permeability and must be fracture stimulated to produce economically. To compound the situation, the Vikulov sands are in the transition zone, and in many places, wet sands are in close proximity to the oil-productive sands. For this reason, many of the initial completions within the acreage had poor results. To improve field performance, a multi-disciplinary team was assembled. The team consisted of a geologist, petrophysicist, completion, production and reservoir engineers, facilities personnel and service company engineers. Their task was to better understand the properties of the Vikulov and the reservoir, determine well locations with maximum production potential, optimize stimulation treatments and provide infrastructure to produce the oil. This paper will review the initial completion efforts and explain the methodology and changes implemented by the team to describe and define the reservoir, modify stimulation methods using a grid-based, non-coupled fracture simulator and optimize well productivity. Production increases in excess of five fold have been realized for many wells.

@inproceedings{mack2006multidisciplinary,
    author = "Mack, D. J. and Bitter, M. R. and Galchenko, R. and Meyer, V. and Housman, J.",
    title = "Multidisciplinary Teamwork Results in Dramatically Improved Production— East Kamennoye, Western Siberia",
    year = "2006",
    booktitle = "SPE Annual Technical Conference and Exhibition",
    abstract = "The Vikulov formation in the Tyumen District of southwestern Siberia consists of incised-valley deposits and shallow-marine delta-front sands, which form oil reservoirs in the area of the Krasnoleninsk dome. Reservoir quality varies considerably depending on the depositional facies. In places, high permeability channels and bars were deposited, whereas the more distal sands have much lower permeability and must be fracture stimulated to produce economically. To compound the situation, the Vikulov sands are in the transition zone, and in many places, wet sands are in close proximity to the oil-productive sands. For this reason, many of the initial completions within the acreage had poor results. To improve field performance, a multi-disciplinary team was assembled. The team consisted of a geologist, petrophysicist, completion, production and reservoir engineers, facilities personnel and service company engineers. Their task was to better understand the properties of the Vikulov and the reservoir, determine well locations with maximum production potential, optimize stimulation treatments and provide infrastructure to produce the oil. This paper will review the initial completion efforts and explain the methodology and changes implemented by the team to describe and define the reservoir, modify stimulation methods using a grid-based, non-coupled fracture simulator and optimize well productivity. Production increases in excess of five fold have been realized for many wells.",
    url = "https://doi.org/10.2118/103116-ms",
    doi = "10.2118/103116-ms",
    openalex = "W2079070530",
    references = "doi10252312273ms, doi10252336424ms, openalexw2256096250"
}

Abstract. Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biogeochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO2) that oversaturates all waters from the surface to bottom relative to atmospheric level, even when primary production, inferred from low surface water nutrients, has occurred. The eastern surface waters were under-saturated with respect to CO2 illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of ~0.8 ± 2 mol C m−2, which when multiplied by half the area of the East Siberian Sea, ~500 000 km2, results in an annual primary production of 0.4 (± 1) × 1012 mol C or ~4 (± 10) × 1012 gC. Microbial decay occurs through much of the water column, but dominates at the sediment interface where the majority of organic matter ends up, thus more of the decay products are recycled to the bottom water. High nutrient concentrations and fugacity of CO2 and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH4), was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from ancient organic matter, becoming available due to sub-sea permafrost thaw and formation of so-called taliks. The decay of organic matter to CO2 as well as oxidation of CH4 to CO2 contribute to a natural ocean acidification making the saturation state of calcium carbonate low, resulting in under-saturation of all the bottom waters with respect to aragonite and large areas of under-saturation down to 50 % with respect to calcite. Hence, conditions for calcifying organisms are very unfavorable.

@article{doi105194bg817452011,
    author = "Anderson, Leif G. and Björk, Göran and Jütterström, Sara and Pipko, I. I. and Shakhova, Natalia and Semiletov, Igor and Wåhlström, Iréne",
    title = "East Siberian Sea, an Arctic region of very high biogeochemical activity",
    year = "2011",
    journal = "Biogeosciences",
    abstract = "Abstract. Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biogeochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO2) that oversaturates all waters from the surface to bottom relative to atmospheric level, even when primary production, inferred from low surface water nutrients, has occurred. The eastern surface waters were under-saturated with respect to CO2 illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of \textasciitilde 0.8 ± 2 mol C m−2, which when multiplied by half the area of the East Siberian Sea, \textasciitilde 500 000 km2, results in an annual primary production of 0.4 (± 1) × 1012 mol C or \textasciitilde 4 (± 10) × 1012 gC. Microbial decay occurs through much of the water column, but dominates at the sediment interface where the majority of organic matter ends up, thus more of the decay products are recycled to the bottom water. High nutrient concentrations and fugacity of CO2 and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH4), was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from ancient organic matter, becoming available due to sub-sea permafrost thaw and formation of so-called taliks. The decay of organic matter to CO2 as well as oxidation of CH4 to CO2 contribute to a natural ocean acidification making the saturation state of calcium carbonate low, resulting in under-saturation of all the bottom waters with respect to aragonite and large areas of under-saturation down to 50 \% with respect to calcite. Hence, conditions for calcifying organisms are very unfavorable.",
    url = "https://doi.org/10.5194/bg-8-1745-2011",
    doi = "10.5194/bg-8-1745-2011",
    openalex = "W2147434008"
}

North East Europe harbors a high diversity of cultures and languages, suggesting a complex genetic history. Archaeological, anthropological, and genetic research has revealed a series of influences from Western and Eastern Eurasia in the past. While genetic data from modern-day populations is commonly used to make inferences about their origins and past migrations, ancient DNA provides a powerful test of such hypotheses by giving a snapshot of the past genetic diversity. In order to better understand the dynamics that have shaped the gene pool of North East Europeans, we generated and analyzed 34 mitochondrial genotypes from the skeletal remains of three archaeological sites in northwest Russia. These sites were dated to the Mesolithic and the Early Metal Age (7,500 and 3,500 uncalibrated years Before Present). We applied a suite of population genetic analyses (principal component analysis, genetic distance mapping, haplotype sharing analyses) and compared past demographic models through coalescent simulations using Bayesian Serial SimCoal and Approximate Bayesian Computation. Comparisons of genetic data from ancient and modern-day populations revealed significant changes in the mitochondrial makeup of North East Europeans through time. Mesolithic foragers showed high frequencies and diversity of haplogroups U (U2e, U4, U5a), a pattern observed previously in European hunter-gatherers from Iberia to Scandinavia. In contrast, the presence of mitochondrial DNA haplogroups C, D, and Z in Early Metal Age individuals suggested discontinuity with Mesolithic hunter-gatherers and genetic influx from central/eastern Siberia. We identified remarkable genetic dissimilarities between prehistoric and modern-day North East Europeans/Saami, which suggests an important role of post-Mesolithic migrations from Western Europe and subsequent population replacement/extinctions. This work demonstrates how ancient DNA can improve our understanding of human population movements across Eurasia. It contributes to the description of the spatio-temporal distribution of mitochondrial diversity and will be of significance for future reconstructions of the history of Europeans.

@article{doi101371journalpgen1003296,
    author = "Sarkissian, Clio Der and Balanovsky, Oleg and Brandt, Guido and Khartanovich, Valery and Buzhilova, Alexandra and Koshel, Sergey and Zaporozhchenko, Valery and Gronenborn, Detlef and Moiseyev, Vyacheslav and Kolpakov, Eugen and Shumkin, Vladimir and Alt, Kurt W. and Balanovska, Elena and Cooper, Alan and Haak, Wolfgang",
    title = "Ancient DNA Reveals Prehistoric Gene-Flow from Siberia in the Complex Human Population History of North East Europe",
    year = "2013",
    journal = "PLoS Genetics",
    abstract = "North East Europe harbors a high diversity of cultures and languages, suggesting a complex genetic history. Archaeological, anthropological, and genetic research has revealed a series of influences from Western and Eastern Eurasia in the past. While genetic data from modern-day populations is commonly used to make inferences about their origins and past migrations, ancient DNA provides a powerful test of such hypotheses by giving a snapshot of the past genetic diversity. In order to better understand the dynamics that have shaped the gene pool of North East Europeans, we generated and analyzed 34 mitochondrial genotypes from the skeletal remains of three archaeological sites in northwest Russia. These sites were dated to the Mesolithic and the Early Metal Age (7,500 and 3,500 uncalibrated years Before Present). We applied a suite of population genetic analyses (principal component analysis, genetic distance mapping, haplotype sharing analyses) and compared past demographic models through coalescent simulations using Bayesian Serial SimCoal and Approximate Bayesian Computation. Comparisons of genetic data from ancient and modern-day populations revealed significant changes in the mitochondrial makeup of North East Europeans through time. Mesolithic foragers showed high frequencies and diversity of haplogroups U (U2e, U4, U5a), a pattern observed previously in European hunter-gatherers from Iberia to Scandinavia. In contrast, the presence of mitochondrial DNA haplogroups C, D, and Z in Early Metal Age individuals suggested discontinuity with Mesolithic hunter-gatherers and genetic influx from central/eastern Siberia. We identified remarkable genetic dissimilarities between prehistoric and modern-day North East Europeans/Saami, which suggests an important role of post-Mesolithic migrations from Western Europe and subsequent population replacement/extinctions. This work demonstrates how ancient DNA can improve our understanding of human population movements across Eurasia. It contributes to the description of the spatio-temporal distribution of mitochondrial diversity and will be of significance for future reconstructions of the history of Europeans.",
    url = "https://doi.org/10.1371/journal.pgen.1003296",
    doi = "10.1371/journal.pgen.1003296",
    openalex = "W2075141855",
    references = "doi101038sjejhg5201712"
}

The polymorphism of the rs174570, rs74771917, and rs7115739 loci of the FADS gene in Siberian populations was studied. It was shown that the frequency of the rs174570-T variant marking haplotype A with a reduced level of fatty acid desaturase expression in the modern indigenous populations increases in the direction from the south to the north of Siberia. Similarly, an increase in the frequency of the TTT haplotype at the rs174570, rs74771917, and rs7115739 loci was observed in the northern direction. However, in ancient times, the populations of Eastern Siberia (its northeastern part, Baikal region, and Primorye) were characterized by an equally high frequency of the rs174570-T variant (over 80%). It was shown that the main influx of the rs174570-C allele (and the CCG haplotype) to northeast Siberia occurred relatively recently, over the past 300 years, as a result of mating contacts between indigenous populations and immigrant groups of predominantly eastern European origin. The gene flow intensity (for the rs174570-C allele) is estimated to be 1.5–4.4% per generation. The appearance of the rs174570-C variant in the population of the Baikal region has been registered since the Eneolithic epoch, which is apparently associated mainly with the advance of the Afanasievo culture tribes to the east of Siberia. Meanwhile, analysis of paleogenomic data showed that the TTT haplotype, with high frequency distributed in modern Eskimos and Amerindians, was present in the Upper Paleolithic population of the Amur region, and therefore its carriers apparently took part in the formation of the ancient Beringian population.

@article{doi101134s1022795424020091,
    author = "Malyarchuk, B. А. and Деренко, М. В. and Denisova, G. A. and Litvinov, Andrey and Dambueva, I. K.",
    title = "FADS Gene Polymorphism and the History of the Formation of the Indigenous Populations of Siberia",
    year = "2024",
    journal = "Russian Journal of Genetics",
    abstract = "The polymorphism of the rs174570, rs74771917, and rs7115739 loci of the FADS gene in Siberian populations was studied. It was shown that the frequency of the rs174570-T variant marking haplotype A with a reduced level of fatty acid desaturase expression in the modern indigenous populations increases in the direction from the south to the north of Siberia. Similarly, an increase in the frequency of the TTT haplotype at the rs174570, rs74771917, and rs7115739 loci was observed in the northern direction. However, in ancient times, the populations of Eastern Siberia (its northeastern part, Baikal region, and Primorye) were characterized by an equally high frequency of the rs174570-T variant (over 80\%). It was shown that the main influx of the rs174570-C allele (and the CCG haplotype) to northeast Siberia occurred relatively recently, over the past 300 years, as a result of mating contacts between indigenous populations and immigrant groups of predominantly eastern European origin. The gene flow intensity (for the rs174570-C allele) is estimated to be 1.5–4.4\% per generation. The appearance of the rs174570-C variant in the population of the Baikal region has been registered since the Eneolithic epoch, which is apparently associated mainly with the advance of the Afanasievo culture tribes to the east of Siberia. Meanwhile, analysis of paleogenomic data showed that the TTT haplotype, with high frequency distributed in modern Eskimos and Amerindians, was present in the Upper Paleolithic population of the Amur region, and therefore its carriers apparently took part in the formation of the ancient Beringian population.",
    url = "https://doi.org/10.1134/s1022795424020091",
    doi = "10.1134/s1022795424020091",
    openalex = "W4392797794",
    references = "doi10325212074813220204111122"
}

The polymorphism of the rs174570, rs74771917, and rs7115739 FADS-gene loci in Siberian populations was studied. It was shown that the frequency of the rs174570-T variant marking haplotype A with a reduced level of fatty acid desaturase expression in the modern indigenous populations increases in the direction from the south to the north of Siberia. Similarly, an increase in the frequency of the TTT haplotype at the rs174570, rs74771917, and rs7115739 loci was observed in the northern direction. However, in ancient times, the populations of Eastern Siberia (its northeastern part, Baikal region, and Primorye) were characterized by an equally high frequency of the rs174570-T variant (over 80%). It was shown that the main influx of the rs174570-C allele (and the CCG haplotype) to northeast Siberia occurred relatively recently, over the past 300 years, as a result of mating contacts between indigenous populations and immigrant groups of predominantly eastern European origin. The gene flow intensity (for the rs174570-C allele) is estimated to be 1.5-4.4% per generation. The appearance of the rs174570-C variant in the population of the Baikal region has been registered since the Eneolithic epoch, which is apparently associated mainly with the advance of the Afanasievo culture tribes to the east of Siberia. Meanwhile, analysis of paleogenomic data showed that the TTT haplotype, with high frequency distributed in modern Eskimos and Amerindians, was present in the upper Paleolithic population of the Amur region, and therefore its carriers apparently took part in the formation of the ancient Beringian population.

@article{doi1031857s0016675824020073,
    author = "Malyarchuk, B. А. and Derenko, M. V. and Denisova, G. A. and Litvinov, Andrey and Dambueva, I. K.",
    title = "FADS gene polymorphism and the history of the formation of the indigenous populations of Siberia",
    year = "2024",
    journal = "Генетика",
    abstract = "The polymorphism of the rs174570, rs74771917, and rs7115739 FADS-gene loci in Siberian populations was studied. It was shown that the frequency of the rs174570-T variant marking haplotype A with a reduced level of fatty acid desaturase expression in the modern indigenous populations increases in the direction from the south to the north of Siberia. Similarly, an increase in the frequency of the TTT haplotype at the rs174570, rs74771917, and rs7115739 loci was observed in the northern direction. However, in ancient times, the populations of Eastern Siberia (its northeastern part, Baikal region, and Primorye) were characterized by an equally high frequency of the rs174570-T variant (over 80\%). It was shown that the main influx of the rs174570-C allele (and the CCG haplotype) to northeast Siberia occurred relatively recently, over the past 300 years, as a result of mating contacts between indigenous populations and immigrant groups of predominantly eastern European origin. The gene flow intensity (for the rs174570-C allele) is estimated to be 1.5-4.4\% per generation. The appearance of the rs174570-C variant in the population of the Baikal region has been registered since the Eneolithic epoch, which is apparently associated mainly with the advance of the Afanasievo culture tribes to the east of Siberia. Meanwhile, analysis of paleogenomic data showed that the TTT haplotype, with high frequency distributed in modern Eskimos and Amerindians, was present in the upper Paleolithic population of the Amur region, and therefore its carriers apparently took part in the formation of the ancient Beringian population.",
    url = "https://doi.org/10.31857/s0016675824020073",
    doi = "10.31857/s0016675824020073",
    openalex = "W4400406463",
    references = "doi10325212074813220204111122"
}

Tracing ice-rafted debris (IRD) in Arctic Ocean sediments is crucial for understanding the evolution of Northern Hemisphere ice cover. However, uncertainties in identifying the provenance of IRD across circum-Arctic shelves have complicated reconstructions of the East Siberian Ice Sheet (ESIS). Here, we present a provenance study using 10,111 detrital zircon U-Pb ages from circum-Arctic shelf sediments and central Arctic IRD. Our results reveal that a prominent \textasciitilde 90-110 Ma zircon peak serves as a distinctive fingerprint for East Siberian-sourced sediments. Central Arctic IRD from at least four glacial periods contains this signature, indicating repeated ESIS glaciation, likely within the past three glacial cycles. This multiphase glaciation of East Siberia exerted significant, though poorly understood, influences on both polar and global climates during the late Quaternary. Our findings provide valuable insights into the history of Northern Hemisphere glaciation and offer an effective approach for reconstructing ice sheet evolution.

@article{doi101038s4146702562499y,
    author = "Feng, Han and Yao, Zhengquan and Shi, Xuefa and Zhang, Zhongshi and Lu, Huayu and Zhang, Hanzhi and Liu, Yanguang and Shan, Xin and Dong, Jiang and Dong, Linsen and Yang, Gongxu and Hu, Limin and Vasilenko, Yuri and Astakhov, Anatolii and Bosin, Alexander",
    title = "Arctic zircon U-Pb ages reveal multiphase glaciations in East Siberia during the late Quaternary.",
    year = "2025",
    journal = "Nature communications",
    abstract = "Tracing ice-rafted debris (IRD) in Arctic Ocean sediments is crucial for understanding the evolution of Northern Hemisphere ice cover. However, uncertainties in identifying the provenance of IRD across circum-Arctic shelves have complicated reconstructions of the East Siberian Ice Sheet (ESIS). Here, we present a provenance study using 10,111 detrital zircon U-Pb ages from circum-Arctic shelf sediments and central Arctic IRD. Our results reveal that a prominent \textasciitilde 90-110 Ma zircon peak serves as a distinctive fingerprint for East Siberian-sourced sediments. Central Arctic IRD from at least four glacial periods contains this signature, indicating repeated ESIS glaciation, likely within the past three glacial cycles. This multiphase glaciation of East Siberia exerted significant, though poorly understood, influences on both polar and global climates during the late Quaternary. Our findings provide valuable insights into the history of Northern Hemisphere glaciation and offer an effective approach for reconstructing ice sheet evolution.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC12350766/",
    doi = "10.1038/s41467-025-62499-y",
    openalex = "W4413116596",
    pmcid = "PMC12350766",
    pmid = "40804234",
    references = "doi101016jchemgeo200406017, doi101016jchemgeo200411013, doi101016jchemgeo201204021, doi101016jepsl200405037, doi101016s000925410200195x, doi101038s41467019116012, doi101038s4158601908899, doi101073pnas1411762111, doi101111j1751908x1995tb00147x, doi101111j1751908x1997tb00538x"
}

Data on mitochondrial DNA (mtDNA) polymorphism at the population level are of significant interest to researchers in the fields of population and ethnic genetics, forensic medicine, and forensic science. In the present study, we have obtained data on the variability of whole mitochondrial genomes in the immigrant East Slavic population of Northeastern Siberia (using the Magadan region as an example). The study yielded novel data concerning mtDNA variability in the Magadan region's inhabitants comprising maternal lineages of Russians (N = 49) and Ukrainians (N = 15), as well as individuals with a mixture of maternal and paternal ancestries, including Russians on the maternal side and indigenous populations (Koryaks, Evenes, and Itelmens) on the paternal side (N = 4). In addition, the mitogenomes of the Russian population from the Novgorod, Kaluga, and Yaroslavl regions (N = 15) were sequenced to enhance the power of the phylogeographic analysis. The results of the study demonstrated that the mitochondrial gene pool of the East Slavic immigrant population in the Magadan region is characterized by a high level of diversity. The analysis of genetic differentiation of Russian populations within Russia, as measured by the variability of complete mitochondrial genomes, revealed a low level of interpopulation differences (Fst = 0.15 %, P = 0.2). The results of multidimensional scaling of Fst distances indicate that the Russians residing in the Magadan region are genetically similar to the Russian populations inhabiting the southwestern part of the country, specifically the Belgorod and Orel regions. The gene pool of the Russian population in the Magadan region is predominantly characterized by mtDNA haplotypes of West Eurasian (including European) origin. The prevalence of East Asian-derived haplotypes among the Russian population is relatively low, accounting for approximately 4.8 % of the total. However, certain East Asian-specific haplogroups, such as F1b1 and Z1a1a, have demonstrated a prolonged presence in the gene pools of Eastern European populations, as evidenced by phylogeographic analysis. Among the European mtDNA haplotypes of Russians from the Magadan region, Eastern European variants predominate, and they also have a high proportion of mtDNA haplotypes specific to Slavs (19.4 %). Furthermore, rare mtDNA haplotypes have been identified in the mitochondrial gene pools of Russians and Ukrainians residing in the Magadan region. These rare haplotypes are linked to the maternal lines of Empress Alexandra Fedorovna Romanova (haplogroup H1af2) and Prince Dmitry, son of Prince Alexander Nevsky (haplogroup F1b1-a3a2a).

@article{doi1018699vjgb2577,
    author = "Malyarchuk, B A and Denisova, G A and Litvinov, A N",
    title = "Mitochondrial genome polymorphism in the East Slavic population of Northeastern Siberia.",
    year = "2025",
    journal = "Vavilovskii zhurnal genetiki i selektsii",
    abstract = "Data on mitochondrial DNA (mtDNA) polymorphism at the population level are of significant interest to researchers in the fields of population and ethnic genetics, forensic medicine, and forensic science. In the present study, we have obtained data on the variability of whole mitochondrial genomes in the immigrant East Slavic population of Northeastern Siberia (using the Magadan region as an example). The study yielded novel data concerning mtDNA variability in the Magadan region's inhabitants comprising maternal lineages of Russians (N = 49) and Ukrainians (N = 15), as well as individuals with a mixture of maternal and paternal ancestries, including Russians on the maternal side and indigenous populations (Koryaks, Evenes, and Itelmens) on the paternal side (N = 4). In addition, the mitogenomes of the Russian population from the Novgorod, Kaluga, and Yaroslavl regions (N = 15) were sequenced to enhance the power of the phylogeographic analysis. The results of the study demonstrated that the mitochondrial gene pool of the East Slavic immigrant population in the Magadan region is characterized by a high level of diversity. The analysis of genetic differentiation of Russian populations within Russia, as measured by the variability of complete mitochondrial genomes, revealed a low level of interpopulation differences (Fst = 0.15 \%, P = 0.2). The results of multidimensional scaling of Fst distances indicate that the Russians residing in the Magadan region are genetically similar to the Russian populations inhabiting the southwestern part of the country, specifically the Belgorod and Orel regions. The gene pool of the Russian population in the Magadan region is predominantly characterized by mtDNA haplotypes of West Eurasian (including European) origin. The prevalence of East Asian-derived haplotypes among the Russian population is relatively low, accounting for approximately 4.8 \% of the total. However, certain East Asian-specific haplogroups, such as F1b1 and Z1a1a, have demonstrated a prolonged presence in the gene pools of Eastern European populations, as evidenced by phylogeographic analysis. Among the European mtDNA haplotypes of Russians from the Magadan region, Eastern European variants predominate, and they also have a high proportion of mtDNA haplotypes specific to Slavs (19.4 \%). Furthermore, rare mtDNA haplotypes have been identified in the mitochondrial gene pools of Russians and Ukrainians residing in the Magadan region. These rare haplotypes are linked to the maternal lines of Empress Alexandra Fedorovna Romanova (haplogroup H1af2) and Prince Dmitry, son of Prince Alexander Nevsky (haplogroup F1b1-a3a2a).",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC12457712/",
    doi = "10.18699/vjgb-25-77",
    openalex = "W4413993661",
    pmcid = "PMC12457712",
    pmid = "41000400",
    references = "doi101002ajpa21649, doi101016jajhg200905001, doi101016jfsigen201706003, doi101038sjejhg5201712, doi101086383203, doi101093bioinformaticsbtp187, doi101111j17550998201002847x, doi101371journalpone0135820, doi10325212074813220204111122, doi1032607actanaturae23425"
}

The paper summarises the results of gamma-spectrometric determination of the activity concentration of the major natural radionuclides (226Ra, 232Th, and 40K) in the surface bottom sediments (84 samples) and a single sample of ferromanganese nodules collected in the East Siberian Sea and the Laptev Sea in 2008-2020. Radium equivalent activity, external and internal hazard, and gamma activity concentration indices were calculated in order to assess the natural pollution and risk level of radionuclides. Activity concentrations ranged 16.5-70.4 (mean 31.0) Bq kg-1 of 226Ra, 21.4-77.9 (mean 40.2) Bq kg-1 of 232Th, and 298-991 (mean 543) Bq kg-1 of 40K for the East Siberian Sea samples. The Laptev Sea samples exhibited ranges 15.5-54.0 (mean 32.9) Bq kg-1 of 226Ra, 23.1-66.4 (mean 41.8) Bq kg-1 of 232Th, and 328-546 (mean 441) Bq kg-1 of 40K. In the case of the ferromanganese nodule sample, the measured activity concentrations were 262 ± 42 Bq kg-1 of 226Ra, 137 ± 35 Bq kg-1 of 232Th, and 323 ± 45 Bq kg-1 of 40K. The activity concentrations of natural radionuclides in the sediments were found to be in close proximity to the global average. Activity concentrations of 226Ra and 232Th in ferromanganese nodules were 8 and 3 times higher, respectively. The subsequent radiological risk assessment indicated that the observed values for the sediments were below the specified threshold values. The values for the ferromanganese nodule sample exceeded these thresholds indicating a potential radiological hazard associated with mining of such deposits.

@article{doi101016jmarpolbul2025118770,
    author = "Ulyantsev, Alexander and Bratskaya, Svetlana and Ivannikov, Sergei and Charkin, Alexander",
    title = "Baseline levels of natural radioactivity in the bottom sediments of the East Siberian and Laptev Seas and assessment of the associated risks.",
    year = "2026",
    journal = "Marine pollution bulletin",
    abstract = "The paper summarises the results of gamma-spectrometric determination of the activity concentration of the major natural radionuclides (226Ra, 232Th, and 40K) in the surface bottom sediments (84 samples) and a single sample of ferromanganese nodules collected in the East Siberian Sea and the Laptev Sea in 2008-2020. Radium equivalent activity, external and internal hazard, and gamma activity concentration indices were calculated in order to assess the natural pollution and risk level of radionuclides. Activity concentrations ranged 16.5-70.4 (mean 31.0) Bq kg-1 of 226Ra, 21.4-77.9 (mean 40.2) Bq kg-1 of 232Th, and 298-991 (mean 543) Bq kg-1 of 40K for the East Siberian Sea samples. The Laptev Sea samples exhibited ranges 15.5-54.0 (mean 32.9) Bq kg-1 of 226Ra, 23.1-66.4 (mean 41.8) Bq kg-1 of 232Th, and 328-546 (mean 441) Bq kg-1 of 40K. In the case of the ferromanganese nodule sample, the measured activity concentrations were 262 ± 42 Bq kg-1 of 226Ra, 137 ± 35 Bq kg-1 of 232Th, and 323 ± 45 Bq kg-1 of 40K. The activity concentrations of natural radionuclides in the sediments were found to be in close proximity to the global average. Activity concentrations of 226Ra and 232Th in ferromanganese nodules were 8 and 3 times higher, respectively. The subsequent radiological risk assessment indicated that the observed values for the sediments were below the specified threshold values. The values for the ferromanganese nodule sample exceeded these thresholds indicating a potential radiological hazard associated with mining of such deposits.",
    url = "https://pubmed.ncbi.nlm.nih.gov/41037949/",
    doi = "10.1016/j.marpolbul.2025.118770",
    openalex = "W4414691717",
    pmid = "41037949",
    references = "doi101007s1096702007069w, doi101016jjenvrad200601009, doi101016jmarpolbul201205005, doi101016jmarpolbul2020111041, doi101016jmarpolbul2020111793, doi101016jmarpolbul2021112658, doi101016jmarpolbul2022113593, doi101016s0016703797003426, doi101038s41598022234496, doi1010970000403219850100000007"
}

The Arctic Ocean is undergoing rapid transformation driven by climate change, including declining sea-ice cover and increasing freshwater inputs, with profound consequences for carbon and nutrient cycling. The East Siberian Sea (ESS), one of the largest Arctic shelf systems, plays a central role in linking terrestrial inputs, primary production, and deep-ocean carbon export. In this study, we combined fluorescence spectroscopy with stable isotope and bulk chemical analyses to examine dissolved organic matter (DOM) dynamics along a shelf-slope transect of the ESS. Our results show that slope-associated sedimentary processes exert a strong control on DOM redistribution and transformation. Enhanced algal production across the Russian Arctic increasingly contributes to organic matter transport toward slope regions. Elevated chlorophyll-a concentrations in waters, together with a pronounced enrichment of protein-like fluorescent DOM (C3), point to strong algal inputs to the continental slope. At mid-slope stations (200-900 m), co-enrichment of dissolved and particulate organic carbon with heavier δ15N signatures suggests intensified microbial remineralization and nitrogen cycling, likely stimulated by sediment resuspension under Atlantic Water influence. These findings highlight the ESS slope as a dynamic benthic-pelagic interface where sedimentary processes reshape DOM composition and act as an important pathway for the supply of bioavailable carbon and nitrogen to the Arctic Ocean interior. Overall, this study highlights the continental slope as an active regulator of Arctic DOM cycling under ongoing Atlantification and sea-ice decline.

@article{doi101016jmarpolbul2026119334,
    author = "Mathew, Silpa and Hong, Jong Kuk and Rhee, Tae Siek and Shin, Kyung-Hoon and Seong, Seeryang and Kim, Ji-Hoon and Chen, Meilian and Hur, Jin",
    title = "Benthic-pelagic interactions and algal-derived organic matter dynamics along the East Siberian Sea slope revealed by fluorescence and isotope tracers.",
    year = "2026",
    journal = "Marine pollution bulletin",
    abstract = "The Arctic Ocean is undergoing rapid transformation driven by climate change, including declining sea-ice cover and increasing freshwater inputs, with profound consequences for carbon and nutrient cycling. The East Siberian Sea (ESS), one of the largest Arctic shelf systems, plays a central role in linking terrestrial inputs, primary production, and deep-ocean carbon export. In this study, we combined fluorescence spectroscopy with stable isotope and bulk chemical analyses to examine dissolved organic matter (DOM) dynamics along a shelf-slope transect of the ESS. Our results show that slope-associated sedimentary processes exert a strong control on DOM redistribution and transformation. Enhanced algal production across the Russian Arctic increasingly contributes to organic matter transport toward slope regions. Elevated chlorophyll-a concentrations in waters, together with a pronounced enrichment of protein-like fluorescent DOM (C3), point to strong algal inputs to the continental slope. At mid-slope stations (200-900 m), co-enrichment of dissolved and particulate organic carbon with heavier δ15N signatures suggests intensified microbial remineralization and nitrogen cycling, likely stimulated by sediment resuspension under Atlantic Water influence. These findings highlight the ESS slope as a dynamic benthic-pelagic interface where sedimentary processes reshape DOM composition and act as an important pathway for the supply of bioavailable carbon and nitrogen to the Arctic Ocean interior. Overall, this study highlights the continental slope as an active regulator of Arctic DOM cycling under ongoing Atlantification and sea-ice decline.",
    url = "https://pubmed.ncbi.nlm.nih.gov/41619716/",
    doi = "10.1016/j.marpolbul.2026.119334",
    openalex = "W7126188167",
    pmid = "41619716",
    references = "doi101007s1223701193866, doi101016jscitotenv201801251, doi101016jscitotenv201805205, doi101016s0967063797000514, doi1010292004gl020900, doi1010292009gl040046, doi1010292018jc014378, doi1010292019jc015920, doi101039c3ay41935e, doi105194bg817452011"
}