ИСКУССТВЕННОЕ ВОСПРОИЗВОДСТВО ПОЛУПРОХОДНЫХ ВИДОВ РЫБ ПРИ РАЗНЫХ СЦЕНАРИЯХ РАЗВИТИЯ ГИДРОЛОГИЧЕСКОЙ ОБСТАНОВКИ В АЗОВСКОМ МОРЕ

Abstract

Background. Semi-anadromous fish species of the Azov Sea were the primary fishing targets before the regulation of the flow of the Don and Kuban Rivers, after the anthropogenic transformation of which artificial reproduction became the main source of recruitment for the populations of these species of aquatic biological resources. Unprecedented climate-induced reduction in the volume of freshwater runoff in 2006–2023 aggravated the deterioration of the conditions for reproduction of anadromous fish species in the aquatic areas associated with fish feeding and rearing facilities and contributed to the decline of their feeding conditions in the sea resulting from a sharp increase in salinity, which led to a reduction in their population abundance. Relevance. In the context of a record reduction in freshwater runoff and increasing salinity of the Azov Sea, the Azov Sea ichthyocenosis undergoes a fundamental restructuring, which requires making a forecast of the possible changes in the habitat of semi-anadromous fish species, as well as evaluating the prospects for artificial reproduction of zander, roach and bream for their preservation in new conditions, which, in turn, serves as the aim of this work. Methods. To predict possible changes in the hydrological regime of the Azov Sea, the expert evaluation method has been used. The expert assessment of possible scenarios of the impact exerted by the modern climate change on the habitat of the aquatic biological resources in the Azov Sea has been done with the regard to the provisions of the Climate Doctrine of the Russian Federation. Results. Under all predicted scenarios for the period up to 2030, the salinity of the Azov Sea will exceed the values optimal for the juveniles and mature individuals of semi-anadromous fish species. Preservation of biologically valuable populations of zander and roach is possible with the continuous operation of hatcheries (spawning and rearing facilities), both in limans and on floodplain. To preserve the population and increase the stock of bream, it is necessary to restore artificial reproduction of this species. Conclusions. In the medium term (until 2030), only roach has a prospect for the sufficient recovery of its stocks, which could happen under the favorable hydrological scenario involving the water content increase in the basin. In all other cases, bream, zander and roach will not be in position to considerably increase their abundance.