Spatial distribution and long-term dynamics of biomass of demersal fish in the zone of the Eastern Sakhalin current (Sea of Okhotsk)

Abstract

According to bottom trawl surveys of 1988–2012, spatial distribution, structure, and dynamics of biomass of demersal ichthyocenosis in the northeastern waters of Sakhalin are analyzed. It is shown that the shelf zone is of decisive importance for formation of fish aggregations in this region. Main fish aggregations in the region are confined to the zone of widened shelf near northeastern lagoons of the island at 52°–53° N. Demersal ichthyocenoses are represented mainly by mass species of Gadidae, Pleuronectidae, and Cottidae. Main trends of long-term dynamics of fish biomass of eastern Sakhalin waters are similar to those in waters of northeastern (Kamchatka) and southeastern (south Kurils) parts of the Sea of Okhotsk. Long-term data indicate a tendency for an increase in the total biomass of fish in the periods of sea warming that are favorable for appearance of strong-year classes in mass species.