Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 5

The ecological and geographical regularities of the spatial differentiation of the fauna of birds and mammals of the seas of northeastern Russia were studied at the end of the winter period of 1987-1988. The aerial surveys covered the Bering, Chukchi, East Siberian Seas, and the eastern part of the Laptev Sea. Mammals are ecologically associated with open sea areas, sea ice, continental and island coasts, and mainland tundra. Wintering flocks of birds form species of inland mountain streams, species common circumpolarly in the Holarctic tundra, marine species of the continental and island coasts of the North Pacific and the Arctic Ocean, including high-latitude endemics. 7 species of mammals and 23 species of birds have been registered. There are 22 bird species recorded exclusively in the Bering Sea (24 % of the marine avifauna of the Russian Far East). In terms of the number of species represented ( n = 9), auks prevail, which are very characteristic of the avifauna of the subpolar marine areas of the Palaearctic. Mammals have been regularly recorded in both the Arctic Ocean and the Pacific research sector. The winter fauna of mammals in the seas of northeastern Russia, in which the number of species is dominated by pinnipeds and cetaceans, makes up 23 % of the total mammalian fauna of this region. In the Bering Sea, 3 areas of concentration of wintering birds have been identified: in the southeast of Chukotka, southeast of Cape Navarin, south of about. St. Lawrence. The maximum density of the bird population (21.8 ind./km²) is in young ice and ice of primary education - where there are many forage polynyas. The population of birds of all types of ice is numerically dominated by fulmar, thin-billed and thick-billed guillemots. Most of the marine mammals were observed on the openings in the contact zones of different types of ice or in the ice openings of autumn formation. Polar bears form clusters near the island. Wrangel, beluga whales - to the east and northeast of Cape Navarin, walruses - to the south of it. The stability of winter spatial groups of walrus and polar bears in the Arctic Ocean, which annually demonstrated similar levels of abundance, has been established. Winter aerial surveys showed that beluga whales and humpback whales are not found north of the Bering Strait, and polar bears are almost never found outside the Arctic Basin.