Influence of the Volga-Kama cascade of reservoirs on the hydrological regime during the flood and the quality of the spawning cycle of fish in the Lower Volga

Abstract

The Volga-Caspian fishing subarea is the most important inland fishery reservoir in Russia. For centuries, this region has been distinguished by the high productivity of mass commercial fish species. The main spawning of semi-anadromous (bream, roach, carp, zander, etc.) and river fish of the indicated subregion takes place in the lower zone of the Volga-Akhtuba floodplain, as well as in the central delta. The creation of the Volga-Kama cascade of hydroelectric power stations in the Volga basin has reduced the annual Volga runoff and a profound deformation of all its hydrological characteristics, which is especially evident during the flood period. The paper presents a detailed analysis of the influence of the Volga-Kama cascade of reservoirs on the hydrological regime during the flooding period and the quality of the spawning cycle of fish in the Lower Volga.