The current state of biological resources of the Kirpili river and their efficient use
The biological resources (phytoplankton, Zooplankton, zoo benthos, macrophytes and fish species varieties) are researched as well as hydro chemical and hydrological modes of the ponds included into the Kirpili river basin. The researches proved the availability of satisfactory conditions for cultivation of marketable fish in the ponds located in the Kirpili river basin. Feeding resources develop relatively well (during the vegetation season phytoplankton biomass reaches in average 24.12±0.23 g/m<sup>3</sup>, Zooplankton - 5.95±0.14 g/m<sup>3</sup>, zoo benthos - 8.38±0.13 g/m<sup>2</sup>), but most of these feed supplies are consumed by fish of low value (roach, silver Prussian carp, silver bream, alburnus, rudd and others) yielding fish products of low quality. Fish productivity of the main part of ponds in average is 40 kg/ha. However the potential yielding capacities of the ponds are much higher. So the calculations of available feed supplies showed that the potential natural fish yielding capacity of the lakes is 1600 kg/ha. To obtain a high fish yield it is necessary to capture out invaluable and predatory species of fish and after that to stock the ponds with valuable fast-growing fish species (carp, silver grass carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), white amur (Ctenopharyngodon idella), red-finned mullet (Liza haematocheilus), sterlet (Acipenser ruthenus), duckbill (Polyodon spathula), sturgeon hybrids and others). The total capture of fish shall reach more than 6 thousand tons. Currently, the total capture of fish does not exceed 240 tons annually.