Salmon as the basis for the functioning of the ecosystem of the Academy Bay (Okhotsk Sea). Possible threats to its degradation

Abstract

In September 2022, high concentrations of total phosphorus and total nitrogen over background 2.5 and 15 μmol/l, respectively, were found by the expedition of POI FEB RAS on r/v “Professor Gagarinskiy” in the apex of the Ulban Bay (southern part of the Academy Bay). These hydrochemical data combined with physiological features of salmon reproduction (nine-month maturation of larvae, rolling of fry, transformation of fry into gregarious pelagic fish, their rapid growth), taking into account of the oligotrophic status of the Academy Bay and the results of observations over bowhead whales, led us to the idea that young salmonid fish are the main food of bowhead whales. The sustainability of the Academy Bay ecosystem strongly depends on the sustainability of pink and chum salmon populations that come to spawn in the rivers of the Academy Bay. Human activity caused by gold and coal mining, salmon fishing and implementation of the idea of creating a tidal power station in the Tugur Bay can lead to degradation of the Academy Bay ecosystem due to destruction of bowhead whales population.