Population structure of walleye pollock within the Asian part of the range based on the analysis of various genetic markers

Abstract

The aim: The aim of this work is focused on a phylogeographic analysis of the relationship between the population groups of walleye pollock Gadus chalcogrammus of the Asian part of the range.The methods: The analysis of phylogeographic analysis is based on the data of polymorphism of microsatellite markers, a fragment of the mtDNA control region (D-loop) and a fragment of the mtDNA cytochrome b gene. The newness: A comprehensive phylogeographic analysis using samples of spawning walleye pollock individuals from most of the Asian part of the range from the Sea of Japan to the northwestern Bering Sea using various genetic markers was carried out for the first time.The results: The results of the analysis of the variability of walleye pollock samples by mitochondrial markers (fragments of the cytochrome b and D-loop genes) allow us to distinguish two large population groupings within the Asian part of its range: the first one in the Sea of Okhotsk, the Sea of Japan, the waters of the Kuril Islands and southeastern Kamchatka and the second one in the Bering and Chukchi seas. Analysis of the variability of walleye pollock samples by microsatellite markers allows us to judge the absence of population groupings in the waters of the Sea of Okhotsk, the Sea of Japan, off the Kuril Islands and southeastern Kamchatka.The practical significance: When regulating pollock fishing in the Russian waters, it is necessary to establish a single total allowable catch (TAC) for each of the two superpopulations: the Sea of Okhotsk —  Sea of Japan (1) and the Bering Sea (2) combining the sizes of proposed catch for walleye pollock groups belonging to each of these superpopulations.