Optimization of latitudinal zoning of the restricted periods of industrial and recreational and sports fishing in the Volga-Caspian fishery basin

Abstract

Article analyzes the existing terms of restriction of commercial and recreational fishing of the Volga-Caspian fishery basin. The necessity of changing these terms is shown. Water temperature was determining as main factor of fish spawning. Values of water temperature at which there comes spawning most important commercial species of fish in the field relation at the spawning species (pike, pike perch, bream, roach, carp) were used. Normaly period of fish spawning in waters of the Volga-Caspian fishery basin is extended 1–2 months. But the period of mass fish spawning is relatively short, and determined by the achievement of the optimal for spawning water temperature and the total amount of heat. The timing and duration spawning the same species of fish, inhabiting water located in different natural and climatic zones, may significantly different. For determining multiyear time frame achieving of spawning water temperatures were analyzed hydrological yearbooks compiled by data of gauging stations on reservoirs, large and medium-sized rivers. Distribution maps are constructed, proposed zoning of regions of the Volga-Caspian fishery basin to overcome water temperature values, 4, 9, 12 °C, which cover the beginning of the spawning season.