Environmental conditions of the north-western Pacific ecosystems: trace element accumulation in Pacific salmon

Abstract

The metals (Cu, Pb, Cd, Ni, Zn and Fe) in Pacific salmon were determined: Masu from the southeast Sakhalin Island coast, collected in 2017, Chum from the of Okhotsk and Japan Seas, collected in 2018-2019 in cages of salmon fish hatcheries and Sockey collected from two bays of the southeastern coast Kamchatka before entering the rivers, in 2021. It was established that the content of Zn, Ni, and Fe noticeably predominate in the organs and tissues of Cherry and Chum from the Sea of Japan, while Cd and Pb concentrations predominate in the organism of the Sea of Okhotsk Chum. The largest amount of copper was found in the organism of Sockey from Kamchatka bays. according to the content of toxic elements (Pb and Cd), all types of salmon meet the sanitary requirements of the Russia for seafood. Probably, the reason for the established difference is the geochemical environmental conditions formed in the closed Sea of Japan under the influence of anthropogenic and terrigenous factors, the influence of natural factors - volcanism and upwellings - in the Sakhalin-Kurilsky basin of the Sea of Okhotsk, also the increased background copper content in the Kamchatka soils because of volcanic activities.