BIOLOGIYA MORYA, 2025, Vol. 51, No. 6, pp. 319-343

Microfossil Taphocoenoses in Surface Sediments of East Siberian Sea and Podvodnikov Basin (Arctic Ocean) and Their Significance for Paleoreconstructions

© 2025 L. N. Vasilenko¹, M. S. Obrezkova¹, I. B. Tsoi¹, S. P. Pletnev¹, V. K. Annin¹, I. A. Yurtseva¹, Yu. P. Vasilenko¹, E. A. Gusev², D. S. Khmel¹

¹Il'ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, 690041 Russia;
²Gramberg All-Russia Research Institute of Geology and Mineral Resources of the World Ocean, St. Petersburg, 190121 Russia

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The article presents the results of a study of the qualitative and quantitative composition of several groups of microfossils (diatoms, radiolarians, benthic and planktonic foraminifers, tintinnids, and probably their cysts, papuliferes) in surface sediments of the East Siberian Sea (ESS) shelf and the deep-sea Podvodnikov Basin (PB) adjacent to the southwestern Arctic Ocean continental slope. The distribution pattern of the studied microorganism groups in the sediments made it possible to identify complexes of these groups and combine them into three taphocoenoses: the inner shelf (18-45 m), the outer shelf (57-104 m), and the southwestern PB slope (1985-2546 m) (the depth ranges are based on available data). Each taphocoenosis is characterized by a unique set of microfossils and reflects the environmental conditions in which it was formed. The taphocoenosis of the inner shelf is divided into western and eastern parts, differing in the influence of various hydrological factors (circulation pattern, river runoff, etc.). The obtained results serve as a basis for monitoring environmental and oceanographic changes in the studied region of the modern Arctic and for paleoreconstructions.

Key words: diatoms, foraminifers, radiolarians, tintinnids, papuliferes, Arctic, East Siberian Sea, Podvodnikov Basin.