Basic trophological elements of walleye pollock and its food supply

Abstract

Objectives: to study the features of the trophology of pollock of different sizes, to identify the dominant species, according to which the seasonal and interannual dynamics of its food supply should be considered in plankton.Methods used: to solve the problem, TINRO databases «Zooplankton» and «Trophology» were used, which exist in the Excell format, when the methods accepted in TINRO were used as standard for collecting and processing fish feeding and plankton samples; complete processing was carried out fresh in the ship’s laboratories.Novelty: the elements of novelty are the identified and refined features of the trophology of the Sea of Okhotsk pollock, a modern assessment of the state of its food supply, calculated data on its structure divided into fractional group and species composition. For a sample of 1000 kg of each pollock size class, tables of their daily rations in kg were compiled, broken down into species for the Sea of Okhotsk and the Bering Sea and the northwestern part of the Pacific Ocean.Practical significance: materials on the trophology of walleye pollock make it possible to evaluate the food base taking into account the needs of each of its size groups, and according to the tables of their daily rations for the Sea of Okhotsk and the Bering Sea and the northwestern part of the Pacific Ocean, it is possible to quickly calculate the total need for food, and, if data on the stock of fractions, groups and dominant species are available, determine their predation, pressure on the plankton community and competition with other species.