Research of the northern single-finned greenling and Pacific beak perch during the specialized fishery in the Bering Sea in April 2021

Abstract

The materials of scientific research of studies of the Atka mackerel Pleurogrammus monopterygius, Pacific beak perch Sebastes alutus and by-catch species carried out in fishing areas of the Far Eastern region (West Bering Sea zone, Karaginskaya and Petropavlovsko-Komandorskaya subzones of Eastern Kamchatka) in April 2021. Data on the productivity of catches and the formation of pre-spawning clusters were analyzed, differences of Atka mackerels biological characteristics in three fishing areas were noted. Ichthyopathological studies of Atka mackerel, Pacific beak perch, Walleye pollock and Alaskan thorny-head were carried out and indicated a low proportion of fish with pathologies of organs and tissues. Danger parasites for humans (Anisakis sp.) and parasites that spoil products (cestodes (Nybelinia sp.) and protozoa (Microsporidia spp.) were noted. A high degree of invasion by the larvae of nematodes Anisakis sp. of the studied fish was established in the liver and body cavity. However, the proportion of muscle damage by these parasites was low. During the study of the gastrointestinal tract of the Pacific beak perch polymer particles were found.