THE PURPOSE. The study of a fish protection structure such as a water-air curtain as an example of an ecological solution to the problem of conservation of aquatic biological resources at an energy facility.METHODS. A comparative analysis of our own research and literature data on the use and evaluation of the effectiveness of fish protection structures (FPS) has been carried out. For the selection of ichthyological samples, mesh networks of 10, 18, 22, 30 and 70 mm were used, installed in front of the water supply channels to the shore pumping stations (SPS). When analyzing the efficiency of the FPS, the methods of fish accounting are considered: the method of catching fish and the procedure for conducting observations at the facility. The assessment of fish ingress to the SPS (after the FPS) was carried out by round-the-clock observations of fish penetrating into the water supply channel in comparison with their ingress to the water-retaining rotating nets of water treatment machines on the SPS. The efficiency coefficient was determined by the difference in the concentration of fish before the FPS (at the reservoir) and after the FPS (at the SPS).RESULTS. It is shown that the efficiency coefficient of the FPS by the type of water-air curtain averaged 86.9%, which exceeds the regulatory efficiency. It has been revealed that a fish protection structure (FPS) by the type of a water-air curtain is the most environmentally friendly technical solution for water intake at power facilities.CONCLUSION. The improvement of the ecological situation in the area of the location of the RSL by the type of water-air curtain in terms of the concentration of oxygen in the water and the reduction of trophies due to the oxidation of organic substances was noted.concentration in water and of decrease in trophy due to the oxidation of organic substances.

The elements of circular technologies in aquaculture on various energy waters are considered. The development of forms of aquaculture from pasture to industrial with an increase in the share of circular technologies is shown. It is noted that the use of cage fish farming on warm waste waters of energy facilities is complicated by eutrophication at high fish stocking densities and the peculiarities of temperature and hydrochemical regimes. The necessity of selection of new aquaculture objects with a fast growth rate, thermophilic and not demanding to the oxygen content in water is noted: a promising object of cultivation in warm waters is the African clary catfish (Clarias gariepinus). Possibilities of including other representatives of catfish - shill catfish (Pangasius) are considered. The results of experimental cultivation of spicy vegetable crops on waste products of crucian carp and clary catfish are presented. The analysis of own data and data of foreign sources is carried out. The dependence of the growth of valuable plant species on the type of fish in aquaponics is shown. Aquaculture and aquaponics as specific components of the modern agricultural sector in the development are focused on industrial production technologies using circular technologies for the efficient use of resources.

The article presents the results of a biochemical study of aqueous media in terms of antioxidant activity, which was studied by coulometric analysis using electrogenerated bromine, the samples were analyzed on the coulometer "Expert-006" (LLC "Econix-Expert", Russia) by a certified method. Modern ideas about the properties of water are based on its cluster structure, which is devoted to a significant number of theoretical and experimental works. They indicate that the structure of water is formed by clusters that are constructed from water molecules held by hydrogen bonds. The 9 clusters of water differing in a set of characteristics are allocated. It is shown that oligotrophic waters with low organic matter content and aligned and simplified community structure of aquatic organisms characterized by a complex cluster structure of water and the lowest values of antioxidant activity and water production characteristics differ by a stable, simplified cluster structure with high values of antioxidant activity of the water. Following the research it is revealed that, water has various cluster structure. The most complex in terms of cluster composition is spring water (5 clusters) and artesian water (4 clusters). The most simple composition was the water of the seas and fisheries ponds-1-2 clusters. It was discovered, that oligotrophic waters with low organic matter content and aligned or simplified community structure of aquatic organisms characterized by a complex cluster structure of water and the lowest values of antioxidant activity and water production characteristics differ by a stable, simplified cluster structure with high values of antioxidant activity of the water.

The article presents the results of a biochemical study of the total antioxidant activity of water during the Clarias gariepinus farming in closed containment aquaculture system, including the dynamics without replacement. For the first time is shown an increasing the total antioxidant activity with the highest values in the lower part of the biological filter. According to the results of daily observation, the fish behavior was adequate until the end of the experiment, which was stopped with the beginning of their mass death (more than 20%). Researches have shown the promise of using the indicator of total antioxidant activity to assess the work of the closed containment aquaculture system for hydrobionts farming. The issues of reducing the cost of farmed fish by the closed containment aquaculture system using aquaponics, which distinguished among other technologies by the high quality of environmentally friendly food products while significantly saving water resources which is an important problem for closed containment aquaculture system are considered. Food plants feed on bacteria from the waste products of fish while they consume the necessary secretion products from water – chemicals (nitrogenous, potassium, phosphorus compounds), naturally purifying the water. Aquaponics simulates the natural whirlpool, using the natural processes of fish vital functions for plants nutrient medium. As food plants can be used Salicornia europaea and glycophyte Nasturtium officinale, which has a high productivity and high content of vitamins, iron and glycosides. Both plants are tested in the closed containment aquaculture system including human, increased degree of isolation.

The features of the industrial reproduction of sterlet in the Middle Volga region are considered. The necessity of further increasing the volume of production and release of juvenile sterlet to the Kuibyshev reservoir is shown. An increase in the relevance of research works in the field of sturgeon ichthyopathology has been noted. The importance of carrying out ichthyopathological observations is shown both for ensuring the stability and efficiency of production, and for preserving the natural population of sterlet in the Kuibyshev reservoir. The article considers the relative novelty of ichthyopathology as a science and the discrepancy between normative legal acts regulating ichthyopathological observations in Russia. The industrialization of aquaculture forms is shown. The emergence of new sturgeon diseases specific to high-intensity fish farming was noted. The results of experiments on the use of inorganic drugs for the treatment of sturgeon nutritional diseases are presented.