Distribution of pacific herring off southeastern Sakhalin (sea of Okhotsk) in the summer and autumn period

Abstract

The aim of the work is assessment of the spatial and density distribution of Pacific herring Clupea pallasii off the southeastern Sakhalin in June-October.Material and methods. It is based on the data of the 1989–2020 bottom trawl surveys.Novelty. For the first time long-term data on the spatial distribution of herring off the southeastern coast of Sakhalin Island are presented from the bottom trawl surveys.Results. Off the southeastern coast of Sakhalin Island herring is found in June in a pre-spawning state at depth of up to 140 m, concentrating abeam the spawning grounds. In July-October, during the feeding period and the initial period of wintering migration, herring spreads almost exclusively at depths of up to 50 m at a water temperature of more than 2–4 °C within the boundaries of the cold intermediate layer, forming the main accumulations in the Terpenya Bay at depths up to 30 m.Practical significance. The data complement the information on the spatial distribution of herring off the southeastern coast of Sakhalin Island in the summer and early autumn, and can be used for making decisions on the rational exploitation of the resource and organizations of trawl surveys.