PRACTISE OF ORGANIZING LAKE COMMERCIAL FISH FARMS IN CONDITIONS OF LAKE OZGENT
The article presents the results of the researches conducted on Lake Ozgent (the Kyzylorda region). The data on hydrochemical regime of the lake, ionic composition, composition of biogenous compounds, oxygen and thermal regimes were collected and analysed. There has been done the assessment of food supply and current state of the ichthyofauna. According to the obtained data, the recommendations about using Lake Ozgent were made, the recommended meliorative events (meliorative fishing, repair of hydroconstructions) were held and stocking the fishing material of carp was carried out. Based on the work results it has been established that in the conditions of Lake Ozgent the pure gain in 5 months of cultivation (on extensive technology when using only the natural food supply) made 385.6 g in a carp, 301.4 g in a white silver carp and 428.7 g in a grass carp. In the full catch of commodity fish species, the overall fish productivity of Lake Ozgent will make 101.9 kg/hectare, of them carp will take 43.4 kg/hectare, grass carp - 13.5 kg/hectare and white silver carp - 45 kg/hectare. The growth of the grown-up fish in Lake Ozgent corresponds to biotechnical standards of fish cultivation in the in polyculture of the feeding lakes.