Reconstruction of the Arrival and Migration of 137Cs and 90Sr in the Ecosystem of the Barents Sea

Based on the analysis of data from long-term radioecological observations in the Barents Sea, the main migration flows of 137Cs and 90Sr in its ecosystem have been reconstructed. In the current (2010–2019) balance of technogenic radioactivity, the transboundary transfer of radioisotopes from the Norwegian Sea accounts for more than 90% of the total intake. Most of the incoming radionuclides are removed from the Barents Sea through its northern and northeastern borders in the process of water exchange. A significant decrease in the concentrations of radionu- clides in the components of the environment and biota in the “post-nuclear era” is shown. The content of 137Cs and 90Sr in the food web of the marine ecosystem was estimated in comparison with the reserve of their activity in water and bottom sediments. The biotas accumulate no more than 0.01% of the total isotope content in the ecosystem.