Heavy metals (HM) occupy leading positions among the pollutants of rivers, streams, channels, lakes, as well as groundwater. In large quantities, HM have a negative impact on living organisms. Their spread occurs quite quickly and leads to degradation of the water body. This paper presents the results of a study of eight water bodies having a commercial category. The studied watercourses flow through the territory of Gusevsky, Chernyakhovsky, Ozersky, Nesterovsky and Slavsky districts of the Kaliningrad region. All studies have been carried out in accordance with the requirements of the documents regulating this type of work. Samples have been taken from the upper horizon during the summer autumn, the content of heavy metals such as iron, lead, cadmium, copper, nickel has been studied. The main sources of anthropogenic impact in the basins of the studied rivers have been determined. After processing the results of laboratory studies of water, it has been found that exceedances of the maximum permissible concentrations (MPC) of iron can be observed in all the studied sites; there has been no excess of the MPC for cadmium; in a sample taken in the alignment of the Osa river an increased content of lead and copper has been found; in the water samples of the Krasnaya, Russkaya, Golubaya rivers there are exceedances of MPC in nickel and copper content; excess of MPC in copper content has been found in the sample of the Putilovka river. Correlation analysis shows that there is no significant level of stochastic relationship between the concentrations of heavy metals (except for Cu and Cd; Cu and Ni), this indicates different sources of HM intake into the studied water bodies.

Biological indicators of bream (Abramis brama L.) – one of the most numerous species and the main object of fishing in the Volgograd reservoir have been studied. Data on the size-age composition and qualitative characteristics of bream in terms of fishing gear in different zones (areas) of the reservoir have been analyzed. According to the research of 2014–2018 the bream population is in a stable state. The catches are dominated by four to eight year olds. In the 1990s, the age structure was unstable and was characterized by a sawtooth population curve. According to earlier data from 1970–1998, the dominant age group was four to eight years old. Indicators of size and age characteristics are close to the average long-term values. The average age of the spawning part of the population is 6.3 years. Conditions for spawning and feeding grounds for juveniles in 2018 were unfavorable. From 2016 to the present, changes in the fishery after its reorganization can be observed. Restructuring consists in the distribution of fishing areas throughout the water area of the Volgograd reservoir. The growth of commercial catch from 371 to 472 t indicates a positive effect of the reorganization of the fishery. Analysis of the data showed that over the years, the age composition of the bream changed from an unstable state to a stable one. This is evidenced by the fact that the dominant age group has remained unchanged. The study of the impact of fishing on the abundance of bream in the Volgograd reservoir in the zonal aspect shows the maximum load on the population. According to the dynamics of the qualitative characteristics of bream caught by various fishing gear, fishing intensification is the limit.

The paper shows a development trend of industrial salmon aquaculture in Russia and discusses some issues of feed production. Sustainability of using sprat waste hydrolysis products – heads of smoked sprats in the composition of mixed fodders has been substantiated. The process of obtaining peptide-protein and protein-fatprotein feed additives as a result of high-temperature processing of sprat waste under pressure in a hydroreactor has been considered. The chemical composition of dehydrated feed additives and mixed feed obtained with their use has been studied. Freeze-dried peptide-protein supplement contains 82.7% water-soluble low molecular weight protein and minor admixtures of fat (8.6%) and minerals (2.0%). Convection dried protein-fatmineral supplement contains 60.9% water-insoluble high molecular weight protein, 20.1% minerals (calcium and phosphorus) and 11.0% fat. Experiments have been carried out on the use of the obtained additives in the composition of feed for the fry of the European whitefish coregonus lavaretus in industrial aquaculture as a source of protein, fat and mineral components. The production of control compound feeds has been carried out on the basis of feed fish meal according to the FAO recipe for salmon. Obtaining experimental compound feeds has been carried out by introducing into the basic formulations, respectively, 5% and 10% protein and protein-fat-mineral additives obtained on the basis of sprat waste hydrolysates. Obtaining experimental compound feeds has been carried out by introducing into the basic formulations, respectively, 5% and 10% protein and protein-fat-mineral additives obtained on the basis of sprat waste hydrolysates. Comparative experiments have been carried out on the cultivation of whitefish fry for 56 days using experimental feeds in an RAS installation with six aquariums. Positive results have been obtained in terms of physiological and growth parameters in the experimental groups of fry relative to the control ones. In the experimental groups of whitefish, there were higher rates of body weight gain, survival, specific growth rate with a decrease in the feed coefficient. The conclusion is made about the rationality of obtaining hydrolyzates of sprat waste and their use as feed additives in the composition of feed for salmon. It is recommended to continue biological experiments with a further increase in the dosages of these additives and conduct appropriate morphobiological and hematological studies.

Food composition of the Red King crab Paralithodes camchaticus (Tilesius 1815) collected in the Zelyonaya inlet of the Barents Sea has been studied. The studied samples include 44 specimens that were collected in August 2015, and 24 specimens – in July 2016. The crab size varies within 40-200 mm. Red King crab is an epibentophagus. Among its food mollusks (mainly bivalves), brown and red algae, and echinoderms are dominated. In addition, foraminifera, polychaetes, amphipods (Caprellida), barnacles and detritus have been found. The Froerman coefficient (the average number of food’s taxon in one stomach) varied in the range of 5.91-6.06, which is almost 3 times higher than in shrimps (predator-gatherers). Based on this data, P. camtschaticus can also be attributed to the predator-gatherers. The inter-annual variations in the food composition of the studied crab in the Zelyonaya inlet are insignificant and it had exercised only for the secondary food items. Among food, crabs, nemerteans, sea anemones, egg capsules (accidental food items) were absent. However, the ratios between some food items in different crab age groups had slightly changed. Based on this criterion, the dominant and secondary food items can be divided into the following groups. On the one hand, these are mollusks (the frequency of which has decreased by one third), which occupy more than half of its volume in the virtual food bolus in juveniles and only one third in adults, on the other hand, foraminifera and bryozoans, which have completely disappeared from it. On the contrary, the frequency of occurrence of seaweed has increased three times, and fish – two times, but their role in the crab's diet has not changed. The frequency of occurrence of algae, detritus and sea urchins has not changed, but despite this, their role in the composition of food, judging by the proportion of volume occupied by them in full stomachs, changes dramatically in mature specimens. Algae, for example, occupy a quarter of its volume, (not 7,1 % of the VEL), i.e. three times more than in 2015. This is probably a consequence of the spatial separation of relatively small and large crab groups.

The article considers the problem of automation of trawl fishing management in order to increase its efficiency and reduce energy and economic costs when fishing using artificial intelligence technologies and predictive modeling on a neural network. The tasks of long-term, medium-term "on shore" according to the specified criteria and short-term "on the ship" with the use of echolocation forecasting data a have been set. The structure of the system, methods of filling centralized and local databases of catch statistics, artificial neural network learning, systematization of prediction results, calculation and automatic generation of input parameters, configuration are given. The input parameters of the neural network, set by the user (codes of the fishing area, trawl, fishing object, its size, season, average daily water and air temperature, wind speed, wave strength at the time of the intended fishing, vessel type) have been determined together with the calculated values found according to the mathematical model of the trawl system (trawl opening, trawl depth) and user criteria (fishing site code, time of day, trawl speed); output characteristics (catch value, fuel consumption, financial costs); criteria for selecting and grouping output information. The paper presents samples of archived catch data. Application of a mathematical model for the connection of the power and geometric characteristics of the trawl has been justified. The areas of application of the obtained results have been proposed, such as design, production, operation of real trawling systems and development of virtual and augmented reality software and hardware complexes that will allow determining optimal fishing sites taking into account energy and economic costs, collecting catch statistics, automating its analysis, generating analytical reports.

The article discusses a reasonable choice of dimensions of a fishing vessel with a large coefficient of completeness. Vessels of this type are relatively new for the Russian Federation, therefore, in most literary sources, there is not enough information on the design of these types of vessels. The characteristics of the ship are determined by solving the classical design problem, using the main and secondary dependencies. In order to be able to draw up design equations, it was decided to perform an additional design study – the stage of the preliminary design. The purpose of this work is to develop the architectural and structural type of the vessel, to develop the general layout and fishing scheme, as well as to perform a number of design and verification calculations to determine the possibility or impossibility of creating a new vessel of this type that meets all modern requirements of the Rules of the Russian Maritime Register of Shipping. The result of the development of the preliminary design of the vessel is a prototype for compiling a system of equations in which the weight and size characteristics of the ship's hull developed at the stage of the preliminary design have been analyzed, as well as model tests have been prepared and carried out to assess the seaworthiness of the vessel and draw up the power equation. The solution of the system of design equations makes it possible to determine the main dimensions and other characteristics of the vessel for subsequent optimization transformations when designing a new project. In order solve the problem, a mathematical apparatus has been developed with design equations, including the equations of buoyancy, mass, capacity, waterline completeness factor, stability, power, elongation, longitudinal completeness factor, as well as boundary conditions and calculation of economic indicators of the future ship. The key indicator of the economic profitability of the project is the efficiency of capital investments. To search for the most efficient vessel, a variant calculation has been per formed – the solution of a system of equations with a variation of some initial data. According to the results of the variant calculation, the most successful combinations of the main characteristics of the vessel, providing the best economic performance, have been determined.

When selling salted products from salmon grown in aquaculture, there are quality preservation problems associated with the fact that the fish loses its initially bright attractive color, and there are also cases of microbiological spoilage within the declared shelf life. Therefore, there is a need for recommendations on the composition of the salt mixture, which helps to reduce the rate of discoloration of salmon fish and increase their microbiological stability. Atlantic salmon (Salmo salar) and trout (Oncorhynchus mykiss) have been used in the experiments. In order to preserve color, the influence of ascorbic and citric acids and their salts, rosemary extract, glucono-deltalactone, lycopene and astaxanthin has been studied, and for microbiological stability, synergists of traditional preservatives - salts of lactic and acetic acids, as well as complex food additives. The main part of the experiments has been carried out on model samples, and in all variants there was a preservative - a mixture of sodium benzoate and potassium sorbate (1: 1) in an amount of 0.02 % in accordance with the technical regulations. On order to determine the change in color characteristics depending on the content of astaxanthin in fish, calibration graphs have been constructed for the optical density of carotenoid alcohol extracts and the quantitative content of astaxanthin has been found. Studies have been carried out on the effect of light and temperature on the change in the color characteristics of Atlantic salmon. The study revealed the ineffectiveness of commercial preparations currently used for injection of fish during salting. A decrease in the total microbial contamination in the presence of salts of lactic and acetic acids has been confirmed. Based on the results of the work, the composition of the mixture has been developed, which stabilizes the quality of salted products from salmon fish. The composition of the salt mixture has been developed to stabilize the quality of salted products from salmon fish produced by the injection method.

The issues of modeling vessel behavior in general and in particular, in critical situations in waves, have been the subject of discussions at international conferences on the safety of navigation for many years. It is in the study of particular cases, confirmed by practice, that critical situations of a bifurcation nature appear (which the designers of ships, especially of large displacement, do not even suspect). The paper considers modeling of stability in waves on the data of tests of self-propelled radiocontrolled models in natural waves, carried out in the San Francisco Bay. Three typical rollover cases have been identified: complete loss of stability, resonance modes, and broaching. Of practical interest in interpreting the behavior of a vessel are the features of roll and overturning with a complete loss of stability and a given level of unsteady external disturbances. The analysis of the mathematical model of interaction has made it possible to establish some general patterns of change in the process of dynamic inclination and capsizing of the vessel with a complete loss of stability, as well as the characteristics of evolutionary dynamics when building a model of interaction. Characteristics of the features of the presented extreme situations are given together with the criterial basis for their normalization. It has been found that pitching under conditions of parametric resonance occurs in a mode close to the main resonance. Therefore, the pitching amplitude under intense external disturbances can also reach significant values exceeding the permissible trim angles. As a result of the analysis, the requirements for the safety of the vessel in the "broaching" mode have been formulated. These requirements are determined by the physical laws of the ship's roll and capsizing, established on the basis of experimental studies. The analysis of the dynamics of the vessel in the "broaching" mode revealed a catastrophic situation arising in the case of a ship leaving the "capture" mode and falling into a "potential hole", into a state of complete loss of stability.

The study has been carried out with the use of long-term arrays of X, Y coordinates and the resulting vector M of the position of the North Pole of the Earth's rotation (PNPER) (m) with the resolution of 0.05 years for the period of 1890–2020 [1] and 1 day for the period of 1962–2020 [2]. According to the model [3], consisting of day-to-day (synoptic) (SI), irregular intra-annual (IIA), regular seasonal variation (SeasV), and interannual (IA) components, estimates of the contributions of each type of fluctuations to the total temporal variability have been obtained. It is shown that the maximum contributions to the variance of the time series [1, 2] in the interval of 1962– 2020 for all parameters introduce IIA (54.3–61.4%); the specific contribution of SeasV is significant (19.1–27.3%); the contribution of IA is noticeable (9.9–24.9%); the minimum contribution falls on SI (1.0–1.7%). In this case, the specific contribution of SI with increasing resolution from one day to 18–19 days decreases by 0.5–0.8%, and the relative error when replacing daily time series with 18–19-day data for the SI contribution is 33.6–43.9 %, and cannot be correctly used to assess the SI contribution. Therefore, the intra-annual variation of the specific contribution and the SI range is considered for all parameters only for the array [2]. At the same time, the maximum in the annual variation of the specific contribution of SI for M occurs in December (3.7 %), and the minimum in June (0.7 %). The intra-annual variability of the SI range for M, Y, and X is characterized by a semi-annual wave with maximums in February–March and September (1.3÷ 1.4 m) and minimums in June and December (0.1÷0.2 m) for M and Y or with maximums in June (1.5 m) and December (1.4 m) and minimums in March (0.3 m) and September (0.4 m) – for X.

The paper considers some problems of technological entrepreneurship in the context of a new reality that has arisen as a result of the hybrid war between the West and Russia, climate change and the Covid-19 pandemic. The Western sanctions significantly restrict Russia's access to components and materials, equipment and technologies, and researchers' interaction with foreign colleagues. Russia's response under the current conditions is transformation of the trajectory of technological development in accordance with the principle of self-sufficiency in key sectors of the economy. The purpose of this work is to study the mechanism of involving young people in technological entrepreneurship by converting university "Boiling points" into entrepreneurial ones using the example of EBP "Kaliningrad". The emerging new reality has exacerbated the problems of developing new equipment and technologies, small innovative enterprises, and engineering and technology development centers. A condition for successful technological development is competitiveness of new products in the foreign market, and the key factor here is the labor potential of market participants, human capital, highly educated people who have undergone professional training at technical universities. In order to do this, an entrepreneurial boiling point should become a connecting link in the public-private partnership, an effective mechanism for involving young people in technological entrepreneurship. In this context, the mission of EBP "Kaliningrad" is presented as a seaside educational, scientific and technological, innovative entrepreneurial center, a supplier of specialists - professionals, new technologies, developing viable marine and coastal ecosystems of the 21st century in accordance with the National Technology Initiative of Russia. The tasks and forms of youth involvement in the technological entrepreneurship of EBP "Kaliningrad" have been formulated taking into account the new reality.