Features spawning of pollock Gadus chalcogrammus in the northern part of the sea of Okhotsk in the 2010s

A significant amount of data collected during spring complex surveys in the northern part of the Sea of Okhotsk allowed us to characterize pollock spawning in the period 2011–2020. It was found that, on average, during the period under review, caviar accumulations of various densities occupied up to 90% of the surveyed water area. In the spring period caviar on the early stages of development was found on a larger area of the studied landfill, with the exception of some marine stations, where it was absent from catches. At the same time accumulations of caviar on the late stages of development occupied a smaller area, and the densest concentrations indicating the beginning of spawning were noted in the waters off southwestern Kamchatka and above the Swan Hill. In the waters off the West Kamchatka coast 75% of the caviar was located above depths of 50–150 m and only 22% – outside the shelf. A similar distribution of caviar was noted in the North Okhotomorsky district – 76% developed within the shelf and 31% – over the deep-water part of the district. In the Shelikhov Bay the densest concentrations of caviar were located above the deep-water trough during all years of research.