Over recent years much attention has been paid to the fishery use of geothermal sources. The prospects for this area are enormous, as it opens up possibilities for managing fish-breeding processes, regardless of climatic conditions. The main objective of the research was a comprehensive study of the technological processes of growing. One of the promising reserves for increasing fish production is the rational fishery use of waste warm water and geothermal sources. Research work was carried out in 2019 based on the farm of “Tengri Fish” LLP, which is located 270 kilometers from Almaty. The collection and processing of materials were carried out according to generally accepted methods in ichthyology and fish farming, followed by their analysis on a PC. Based on the results of the research, technological primaries of growing tilapia in a RAS (Recirculating Aquaculture System) using geothermal waters were determined. During the research, work was carried out to optimize the hydrochemical regime. The main fish breeding and biological indicators for the growth and development of tilapia were established. The optimal stocking density of tilapias in recirculating aquaculture systems using geothermal waters and the temperature when tilapias have a higher average daily weight gain were found. The novelty of the research: a complex study of biology and adaptation of a new object of industrial fish farming of tilapia and clarium catfish has been carried out outside the range and determined the adaptation possibilities of tilapia and clarium catfish to extreme factors of the aquatic environment.

In this article, the study and prediction of the state of fish resources in the Yesil River was carried out to determine the boundary reference points of the reserve and management decisions in case they are exceeded, to ensure sustainable fisheries and preserve biological diversity. Ichthyological studies, retrospective analyses and rankings of the effects of the water supply of the Yesil River on fish stocks have been carried out, critical values ​​of the biomass of fishing reserves have been determined, as criteria for biologically safe fishing values and targets for management of fish stocks at reaching the boundary values ​​of 24.03 tonnes have been established. According to the results of studies of basic biological indicators, it was determined that roach, bream, pike and perch populations each had an LC50 above LM50, which indicates their low utilization in the fishery industry. A strategy for management of fish stocks, recommendations for the conservation of fishery resources and their rational use has been developed as a result of these findings. The list and status of the monitored indicators for the careful management of fish stocks, as well as a list and indicators of the boundary indicators for the state of fish stocks, was established. These parameters included the fish size of 50% of the sampled fish and 50% of maturity achieved, where the LC50 was observed in the fish in question from 19 to 45.4 cm and LM50 from 12.3 to 41 cm, respectively. The minimum and maximum river levels that ranged from 111 up to 159 cm, as well as the critical value of the commercial reserve, corresponded to the boundary value of 24.03 tonnes. The results of this work will serve as the basis for making future managerial decisions, necessary for sustainable fisheries and conservation of the biological diversity of the Yesil River.

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