Arctic | Fishes and Fish Habitats
Polar cod ( Boreogadus saida ) as a key fish species of marine ecosystem of the Laptev Sea Presenter: Pavel O. Emelin , emelin@vniro.ru, VNIRO Olga Maznikova , maznikovao@vniro.ru, VNIRO Alexei M. Orlov , orlov@vniro.ru, Shirshov Institute of Oceanology of the Russian Academy of Sciences
The Laptev Sea is the least studied among the seas of the Russian Arctic due to its remoteness, severe climatic conditions, low human population, lack of stationary research bases and other socio-economic factors.
The aim of the work is to characterize the composition and species structure of the ichthyofauna of the Laptev Sea with a focus on the Polar cod ( Boreogadus saida ) as a key species.
In 2015 and 2019, bottom trawl surveys were carried out on board of R/V “TINRO” and R/V “Professor Levanidov” in the summer-autumn period (August-September), when the sea was as free from ice cover.
The ichthyofauna of the Laptev Sea is characterized by low species richness. To date, 81 species have been registered in its composition. During the research in 2015 and 2019, 37 species of fish were found in the catches. In the entire research area, the greatest species richness was observed for the families Liparidae – 7 species, Cottidae and Zoarcidae – 5 species each, Gadidae – 3 species. The remaining families were represented by no more than 1-2 species. Gadids absolutely dominated the catches in terms of abundance (98.67% in total), while the share of Polar cod was 98.66%. The total contribution of the remaining families was only 1.3% of the total abundance. The contribution of families Cottidae and Pleuronectidae were about 0.4% each, while that of the others did not exceed 0.2%. The results of the studies conducted indicate that the structure of the fish communities of the Laptev Sea was monodominant. The dominant species both in terms of biomass and abundance was the Polar cod. At the same time, this is a key species in the functioning of the ecosystem, since it is the main consumer of plankton and an important component of the diet of top predators. Given the high abundance, today Polar cod may be the only promising target of fishing in the Laptev Sea. Nevertheless, it is necessary to assess the extent of Polar cod consumption by top predators in order to determine which part of the population can be available for fishing without compromising reproduction and satisfying the feeding of predators. Currently, severe ice conditions, great distance from ports and fisheries infrastructure and low cost of production make the fishing for Polar cod in the Laptev Sea unprofitable.
Alaska Marine Science Symposium 2023 220
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