Effectiveness of fish natural reproduction depending on the hydrological regime of the volga river during spring and summer
In the paper, we present an assessment of the conditions and effectiveness of semi-anadromous and river fishes’ reproduction in the lower reaches of the Volga River, depending on the volume and hydrological characteristics of spring high water and temperature regime. The influence of these factors, including the duration of flood and juveniles feeding, on the spawning periods of producers for semi-anadromous and river fish, the number of young fish, includes viable, at the end of the flood period is shown. Comparative data are presented, in particular, for the main commercial species - vobla and bream. The data is obtained as a result of studies at the spawning grounds of the Volga River’s delta in different years of the current decade. As a result of unsatisfactory water quality from the Volgograd hydroelectric complex during the flood, the fishing industry of the Volga-Caspian region is being inflicted enormous damage, which scale reflects in commercial catches in subsequent years.