Information is given about the need to study the biological and ecological features of the manifestation of fish diseases when teaching the course «Fish diseases», in connection with the new conditions of industrial fish farming.

Based on the analysis of the regulatory framework and economic assessments, the ongoing measures to prevent and minimize damage to aquatic biological resources, as well as their natural habitat, are analyzed. On the example of the Amur Region, it is shown that the selected measures related to the artificial reproduction of carp are not effective and require significant adjustments.

The work is devoted to the study of the influence of abiotic factors, primarily the salinity level on the productivity of artemia in aquaculture in situ. The problem is relevant, since in the last decade there has been an increase in global aquaculture production by 35%, which has led to an increase in the need for artemia cysts and the nauplia obtained from them. Due to the shortage on the world market of artemia cysts extracted in natural ecosystems and their high cost, there is a need to improve the methods of cultivating artemia in a closed cycle in an artificial ecosystem – in aquaculture. To develop effective methods of cultivating artemia in situ, it is important to know the production and morphological indicators of different types of artemia and its races in an artificially created environment. It is known that there is a wide ecological valence of the reproductive function of artemia in relation to varying environmental factors. One of the most important factors determining the reproductive potential of artemia is the salinity of the environment. The level of salinity of water has a great influence on the productivity of artemia crustaceans, both in the natural environment and in aquaculture. The aim of our study was to assess the reproductive potential of artemia and optimize the salinity of the environment to increase the reproductive potential in conditions of artificial breeding in situ. The results of the study showed that with an increase in the concentration of salt in the solution for the cultivation of the available artemia race – A. var. Principalis, – the proportion of synchronously fruiting females increased. When studying the absolute fertility of artemia, it was shown that an increase in the salinity level of the habitat at the reproductive age of females makes it possible to increase their absolute fertility when growing in a closed cycle in aquaculture.

The article discusses the essence and stages of the formation of a new field of knowledge – the economy of the World Ocean. The importance of sustainable approaches to the economic development of the marine industry is shown. The authors performed an analysis of the bioeconomical essence of industrial entrepreneurship. The dynamics of the components of the bioeconomical analysis is substantiated. The interrelation and mutual influence of these components is revealed. In bioeconomical assessments, significant databases containing diverse and high-quality indicators related to the need to choose an alternative based on methods related to different fields of knowledge are involved in the analysis. The authors of the article believe that in situations involving a large number of variables, modeling and mathematical programming techniques are the most effective means for making managerial decisions. These methods are justified in the article.

Paper presents the data about the catches of the Baltic sprat in the Eastern part of the Gulf of Finland from 1995 to 2021. The size and age characteristics of the sprat taken during the trawl fishing in autumn 2020-2021 are given. The analysis of nutrition and maturation, feed base and the factors limiting the fish growth is carried out.

The article presents a review of published materials and results of specialized ecological and fishery research for the period 1950-2021, containing data on abundance and biomass of the main groups of hydrobionts (phytoplankton, zooplankton, zoobenthos), larvae and young fish in different shelf areas of northern and northeastern Sakhalin Island. Regularities of distribution of different plankton groups by shelf areas and by different water, horizons are considered. Quantitative indicators of systematic groups of hydrobionts and juvenile fish of different shelf areas are compared. The work summarizes the materials on the Zapadno-Shmidtovsky and Deryuginsky license areas, Yuzhno-Kirinsky hydrocarbon field and others.

The article presents the results of hydrobiological monitoring of the water area of the Sea of Azov in the late autumn period of 2021. The characteristics of the taxonomic composition and quantitative indicators of zooplankton and zoobenthos are given, the distribution of hydrobionts by dominant species is shown, and saprobity indicator species are noted.

Object of research: the North Kuril fishing zone. The purpose of the work is to characterize the state of the Russian fishery in the North Kuril zone of the Far Eastern fishery basin of Russia in 2000-2021. Result: The average long-term recommended value of fishing harvest in the North Kuril zone is 146.75-319.71 (244.54) thousand tons. At the same time, the average longterm development of aquatic biological resources is at a high level - 88.89- 259.53 .76) thousand tons or 76.4%. The high proportion of exploitation of commercial aquatic organisms implies a limited possibility of expanding fisheries by increasing the gross catch. The development of the fishery complex of the region, obviously, should be ensured through comprehensively substantiated logistics and technological solutions.

Data on ecological features and commercial development of the main smelt species living in the Khabarovsk Territory are presented. The role of smelt in the structure of aquatic biological resources of the region at the present time is analyzed. The information obtained can be used to substantiate their rational fishing and reproduction.

The results of ecological monitoring of the hypergaline lake Kulundinskoye of the Altai Territory in the period 2021-2022 are presented. The research was carried out in the form of a comprehensive study of abiotic factors of the reservoir (climatic features of the lake, temperature regime, salinity of water), biological factors (species composition of brackish-water zooplankton, its abundance), production and structural indicators of the gill-legged crustacean Artemia Leach, 1819. Desalination of water during the transgressive period of water content caused successional speciation processes. There was a change of the gill-legged crustacean as a dominant and monovid to a complex of brackish-water fauna. The artemia population developed under the influence of unfavorable salinity of water with a fluctuation in the lake from 1.9 (April) to 99.0 mg/dm³ .

The influence of the transgressive phase of water content on the biota and the extraction (catch) of a biological resource - artemia (at the stage of cysts), as well as the importance of the formation of their commercial accumulations of abiotic environmental factors, is shown. Studies have shown that the prevailing combination of factors during the transgression period – tense climatic conditions, low salinity of water (less than 100 mg/dm³), low number of artemia crustaceans, was the absence of commercial accumulations of biological resources.

Taking into account the depressive condition of the Baikal omul resource, the decree of the Ministry of Agriculture of the Russian Federation No. 450 dated August 29, 2017 strict restrictions were established on the catch of Baikal omul in order to restore its reserves. Since 2021, a hydroacoustic method based on hydroacoustic surveys has been used to estimate its recovery. In 2021, on the fishing areas of Lake Baikal (Selenga shallow water and Northern Baikal) there were conducted surveys. In 2022, in addition to these areas, the researches were conducted in the Barguzin Bay and the Small Sea. Significant increase in the number of small omul was observed in the Selenginsky shallow water area in 2022. The results of a comparative analysis on Northern Baikal within the water area of 2021 showed that, taking into account confidence intervals, the number of omul and its biomass practically did not change. The averages omul biomass and number per unit area in the Small Sea were significantly lower than in the waters of the Selenginsky shallow water and the Northern Baikal. The lowest average densities were recorded in the Barguzin Bay.

Technological solutions used in the course of artificial reproduction of chum salmon (Oncorhynchus keta) in the conditions of private salmon farming in the Magadan region are considered.

The potential effectiveness of fish-breeding measures carried out in the conditions of the Takhtoyam fish hatchery to preserve the stocks of chum salmon and increase the volume of its catch in the rivers of Shelikhov Bay is shown.

We analyzed the feeding efficiency of pink salmon (Oncorhynchus gorbuscha), chum salmon (O. keta), masu salmon (O. masu) and coho salmon (O. kisutch) juveniles at the federal fish hatcheries of Sakhalin during seven fish breeding cycles using starter feeds from «Aller Aqua» (Denmark) and «Aquatech» (Russia). It was established that the feed coefficient when using Russianmade feed was lower at all enterprises and when growing juveniles of each salmon species. In addition to the quality of the feed itself, this may be due to the combined effect of two factors, firstly, with the use of special feeds with biologically active additives to stimulate immunity at the initial stages of feeding, and secondly, with the presentation of feeds in two flotation options «conditionally floating» or slowly sinking and «floating» or floating, as well as the selection by experience for each enterprise of the most suitable option.

In order to increase the level of fertilization of eggs, the effect of buffer solution on sperm activity and the effectiveness of its use as a medium for insemination eggs of rainbow trout which was grown in conditions of flowing water and in recirculation aquaculture system (RAS), as well as Ladoga palia, were tested. In male trout and palia, the number of motile spermatozoa and their activity were higher in solution than in water. In trout which was grown in running water, the percentage of eggs fertilization increased significantly when use solution only in cases when the eggs were contaminated with the contents of burst eggs. In fish grown in the RAS, the replacement of water with a buffer solution increased the level of fertilization in all test variants, regardless of the presence or absence of contamination of the eggs. In Ladoga palia, the result of insemination was the same in water and in solution.

A model for calculating the processes of sampling trapping crab orders from great depths is proposed. The sampling process was simulated with a uniform sampling process using nodal connections when connecting traps to the line. Simulation of hauling processes when hauling was stopped and the winch turned on at maximum speed showed a significant load on the main line with a loss of its strength. Loads when hauling from great depths are much more than 10 tons than stipulated by the rules of fishing for winches. Line wear with the calculated loads on the winch turrets are consistent with the factors of line wear in practice and the choice of winches with 20 tons of effort in the field.

The design of existing fishing schemes is carried out according to prototypes, which causes a low level of safety in fishing operations, and, as a result, leads to an increase in accidents among crew members. As practice shows, such cases can be avoided already at the stage of designing a field scheme. In order to find out how changes in fishing schemes in the direction of increasing safety will affect their efficiency of use, the paper proposes to assess the safety risks of a fishing scheme, where the criterion of safety risks acts as the main criterion. To conduct such an assessment, a review was made of largecapacity stern trawlers in the amount of 5 units, with the power of trawler power plants from 882.6 kW to 5295 kW. After evaluating the safety risks of these vessels, the dependences of the safety risk factor on the power of the power plant and the power of the fishing equipment spent on operations were obtained. This analysis was carried out on the basis of a previous study on the efficiency of fishing schemes, where the main criterion was the coefficient of mechanization of fishing operations.

Data are presented that determine the directions of processing and use of brown algae, including the hydration coefficient (HC) of dried thalli or crushed into pieces of various sizes, which is an important indicator used in setting the parameters of technological processes, as well as the yield of finished products. The results are presented demonstrating the ability of the dried algae Saccharina japonica to limit hydration. It has been shown that during deep treatment of S. japonica in order to increase the HC, about 80% of biologically active substances are lost, with the exception of fiber, some part of the protein, the organic form of iodine, as well as alginates associated with polyvalent metal cations in waterinsoluble complexes with alginic acids. It was determined that when soaking dried S. japonica in water, the relative content of alginic acid increases, while the HC of kelp also increases. It has been established that HC equal to 20-26 corresponds to a significant removal of extractive biologically active substances (BAS) from S. japonica. At HC 14-16, up to 50% of biologically active substances remain in the tissues of algae, giving taste to kelp algae and their biological value. It has been shown that with the content of biologically active substances in algae up to 50% of the initial value, a real opportunity is created to obtain food and therapeutic and prophylactic products from dried S. japonica.