Characteristics of feeding migrations of hatchery juveniles of pacific salmon in the basin of Okhotsk Sea and adjacent Pacific waters in the autumn-winter period (regional identification, abundance and distribution of catches, bio-logical indices, estimates of mortality)

Abstract

Long-term data on feeding migrations of hatchery pacific salmon (pink and chum salmon) in the Okhotsk Sea and adjacent Pacific waters in the autumn-winter of 2011–2021 are generalized. The study is based on materials (otolith samples, biological indices) collected in the trawl surveys conducted by TINRO, as well as on international statistics on releases and tagging of pacific salmon at the Russian and Japanese hatcheries. The main patterns of intraspecific structure, migration routes, spatial distribution, and volumes of catch are determined for these species, as well as the size-weight parameters of fish originated from different regions. Natural mortality of salmon juveniles at the stage of migration from the coastal zone to the open sea is estimated at systemic level for the first time.