Changes in the value of the Volga-Sviyazhsky area for fish reproduction the largest reservoir in Europe - the Kuibyshev reservoir

Abstract

To estimate the current significance of the area for fish breeding, the species composition and abundance of young-of-the-year of the coastal zone of the Volga-Sviyazhsky area of the Volga stretch of the Kuibyshev reservoir for 2021, 2022 were considered. The work to assess the species composition and abundance of the young fish was carried out at 7 coastal stations, at depths less than 2 meters. The number of young-of-the-year was calculated per unit of effort of the fingerling seine. Species diversity was assessed using the Shannon-Weaver index. Young of 23 fish species were identified, which confirms the reproduction of these species in the study area. Observational data are compared with earlier materials from 1993-2020. A trend towards an increase in the relative abundance and the species diversity of the young of fish, mainly due to low-value species, was noted. At the same time, in 2022, a relatively high abundance of the young, the main commercial species of the reservoir, the bream, was revealed.