BIOLOGICAL SUBSTANTIATION OF RUSSIAN STURGEON <i>ACIPENSER GUELDENSTAEDTII </i>AND STELLATE STURGEON <i>ACIPENSER STELLATUS </i>COMMERCIAL MEASURE IN THE VOLGA-CASPIAN FISHERIES BASIN
From the data on the dynamics of abundance and biological characteristics of sturgeons in the Caspian Sea and spawning populations in the Volga River the commercial measure of Russian and stellate sturgeons was determined. In view of changes in cohort abundance during its life cycle natural mortality of these species was calculated. Recommendations are presented concerning the use and conservation of sturgeon populations based on their present state.