ASSESSMENT OF THE SPECIES STRUCTURE OF JUVENILE FISH COMMUNITIES IN THE DNIESTER RESERVOIR

Abstract

The study of the qualitative and quantitative components of the structure of juvenile fish communities, as well as their distribution in the reservoir is an important component of comprehensive ichthyological studies of fish biology and ecology in specific hydroecosystems, especially under conditions of anthropogenic impact. Such studies are important for the development of measures to preserve the biodiversity of aquatic ecosystems, allow to assess the current species composition of fish and the effectiveness of spawning of individual species in the current year, to develop biological substantiation of biological reclamation measures and to predict future catches. The article analyzes the results of ichthyological studies conducted in different parts of the Dniester reservoir during 2016-2020. It was shown that the conditions of natural reproduction of native fish fauna in the Dniester reservoir are unstable. During the study period, juveniles of 24 fish species were recorded in the Dniester reservoir, with 3 species present in the catches every year. In unfavourable hydrological years, the dominance of juvenile fish communities of low-value species (silver carp) was noted in the reservoir, while the number of juveniles of valuable rare and commercial species remains at a very low level. The problem of increasing the fish productivity of the Dniester reservoir cannot be solved without the purposeful formation of the fish fauna composition by introducing into the reservoir the fish-planting material of native fish obtained as a result of artificial reproduction