The state of stocks and catches of commercial fish species of the Azov and Black Seas for the period 2000–2020: dynamics and trends

Abstract

The aim to review the state of stocks and fishing against the background of changes in habitat conditions, commercial fish species of the Azov and Black Seas for the period 2000–2020.Materials: Regular scientific research, including: hydrological, hydrochemical, hydrobiological studies, bottom trawl and pelagic lamparian ichthyological surveys; collection and analysis of commercial biological information; analysis of commercial statistical data.Novelty: The dynamics of the values and state of stocks of commercial fish species in the conditions of climate change is shown. In the Black Sea, the increase in the average temperature of the mixed layer, the deepening of the upper boundary of the thermocline in the summer, as well as the slowdown in the cooling of the sea in the autumn-winter period has a negative impact on the productivity of the boreal ichthyofauna and the sprat (sprat) fishery; changes the timing and intensity of migrations of some species of the Mediterranean ichthyofauna, their wintering sites, areas of formation of commercial clusters and, accordingly, the effectiveness of fishing. In the Sea of Azov, the increase in salinity caused by a steady reduction in the volume of freshwater runoff of the Don and Kuban rivers and its replacement by advection of the Black Sea waters is the most important abiotic factor in changing habitat conditions. The increase in the salinity of the Sea of Azov has led to the transformation of traditional hydro- and ichthyocenoses. The gradual transition of the Sea of Azov under the jurisdiction of the Russian Federation makes it possible to more effectively apply resource-saving and resource-restoring measures in order to develop the fisheries potential of this inland sea.As results: the results obtained in this work on the assessment of the impact of anthropogenic and climatic changes will be used to clarify the projected production (catch) of commercial fish.