Increasing fish farm productivity criteria with the help of various intensification measures (feeding fish, fertilizing ponds, increased stocking densities) leads to the emergence of fish infectious diseases. Educational and experimental farm is a multi-level pond farm that contains spawning, nursery and feeding ponds. It is used for commercial carp cultivation. On its territory, amateur fishing is also carried out. While studying pond economy, most frequently we register diseases of a bacterial nature. Test material has been carps of different ages. The primary bacteriological sowing has been carried out according to the method generally accepted in ichthyopathology. Microorganisms have been identified to genus and species with the help of a combination of cultural, morphological and physiological & biochemical signs using the Bergey bacterial manual. Microbial pathogenicity has been identified on the basis of proteolytic activity. The species composition of the carp microflora of the educational and experimental economy of Kaliningrad State Technical University in the period from 2018 to 2020 has been studied. As a result of microbiological analysis, groups of sanitaryindicative, saprophytic and opportunistic miscroorganisms have been identified. Isolation from the blood and parenchymal organs of bacteria of the genus Pseudomonas and Aeromonas, which can serve as virulent agents, indicates a possibility of carp infection due to the cultivation technology violation. When bacterial infections in pond farming happen, the economic damage can be significant, and treatment can be very expensive. Opportunistic bacteria that colonize pond farm carp can become virulent and provoke occurrence of epizootic process if fish resistance weakens and stressful conditions for the fish occur. Bacterial epizootics develop very quickly and can cause death of the entire fish stock in a pond farm. Therefore, any disease is better to prevent than to cure. But in order to develop preventive measures, it is necessary to constantly monitor the causative agents of various bacterial diseases in the pond economy.

The article is devoted to identification of the biodiversity of Lumbricidae in drained cultivated soils of varying degrees of gleying. The studies were carried out in 2020–2021 in the hay field in the Chernyakhovsky district of the Kaliningrad region (Lava-Pregolskaya lowland) and in the arable field of the Zelenogradsk district (Sambian plain). Representatives of Annelida and Mollusca types in the mesofauna of soils have a similar share, Nematoda species predominate. Representatives of eight main classes of the Arthropoda type are found in all soils. A neutral reaction in Sodpodzolic soils (Aric, Siltic, Drainic) in haymaking is favorable for earthworms (115– 159 pcs/m² ), and increased acidity in gley Cambisols (Aric, Loamic, Drainic) under barley culture negatively affects their numbers (on average 58 pcs/m² ). Gleysols (Aric, Siltic, Drainic) with a period of surface flooding contain an average of 95 worms per 1 m2 . In catenas, there is an increase in the number of earthworms from elevated and less moistened areas to lowered and more moistened soils. Dendrodrilus rubidus f. tenuis, Octolasia lacteum, Lumbricus rubellus, Aporrectodea caliginosa, Lumbricus castaneus, rarely Eiseniella tetraedra were found in Gleyic Albeluvisols (Aric, Siltic, Drainic) in the hay field. Aporrectodea caliginosa, Lumbricus rubellus predominate in arable Cambisols (Aric, Loamic, Drainic). The largest number of earthworms is usually concentrated in a layer of 0–10 cm. But in the Cambisols in June, this layer dries up and seasonal migration of worms to a depth of 10-20 cm is observed. Such a type of earthworms as Octolasion lacteum is an indicator of soils with a close occurrence of carbonates (CaCO₃), and Eiseniella tetraedra occurs mainly in soils with a period of surface flooding.

A possibility of using a collagen fiber fraction (CFF) obtained from fish scales as an additive in the test dumpling shell (based on wheat flour) has been studied. General chemical composition (including calcium and phosphorus) of the additive obtained from pikeperch and carp scales is presented, where the content of moisture is 5.1 %, protein – 76.3 %, fat – 1.4 %, total ash – 17.2 %, calcium – 5.1 %, and phosphorus – 3.9 %. Test samples have been obtained, with the addition of various concentrations (1 %, 2 %, 4 %, 6 %, 8 %, 10 %) of CFF, from which test dumplings have been prepared, stored at 18 deg C for 2 months. It has been found that the test dumpling shells with the addition of CFF had an increased mass fraction of moisture compared to the control (without additive) before cooking and a smaller weight gain after cooking (in the range of adding the additive to the dough from 1 to 8 %). It has been noted that with an increase in the mass fraction of the CFF additive in the test dumpling shell, the mass yield of the boiled product increases. It has been found that inclusion of CFF in the recipe of the test dumpling shell in the amount of 2–3 % is optimal. Experimental samples of dumplings stuffed with pollock with CFF additives in the dough in an amount of 2 % and 3 % have been made, and the general chemical composition of the boiled test shell and the finished product has been determined. It was found that when cooking in water, dumplings with CFF additives also had a smaller weight gain compared to the control. Addition of CFF to the test dumpling shell contributed to the improvement of its organoleptic characteristics (rich taste and soft texture), as well as to an increase in the mass fraction of protein in the casing.

Currently, the world community is seriously concerned about the rapid and unpredictable growth in the use of synthetic food packaging, which leads to a constant accumulation of non-biodegradable waste, the disposal of which is difficult and expensive. This determines the rationality of replacing such packaging materials with biodegradable edible films, in particular, based on pectin substances of natural origin, which are natural structure-forming agents obtained from non-recyclable waste during the processing of plant materials. In this aspect, it is interesting to use watermelon peels, a significant part of the harvest of which does not reach the consumer due to its insufficient condition or simply remains in the fields unharvested. Moreover, the watermelon rind contains up to 13,4 % of pectin substances, 8,1 % of which are protopectin, which determines the strength parameters of berry tissue. To solve the problems posed in the work, in particular, the choice of rational operating parameters and modeling of drying, a study of its statics has been carried out by determining the hygroscopic characteristics and thermodynamic regularities of moisture absorption by pectin gel from a watermelon rind, which made it possible to determine the binding energy of moisture with a dry residue and, as a consequence, in fully assess the energy consumption during the procedure of its dehydration, as well as recommend the final rational moisture content of the finished product as a result of the drying process for its long-term preservation during its use and storage and, in addition, determine the appropriate environmental parameters that need to be maintained in commercial, industrial and warehouse premises.

The projected growth of fish products will entail an increase in the volume of unused waste, which protein part is significantly represented by collagen. The global market for this product is expected to double in 10 years in financial terms, while marine collagen has an advantage over the collagen of terrestrial animals due to its low immunogenicity, absence of associated zoonotic diseases and religious restrictions on its consumption, as well as low cost. As a result of comparing the most widely produced type I collagen with the type V collagen we obtained, a suggestion has been made about the unique characteristics of the supramolecular structure of the latter, due to the cyclical development of placental tissues. An overview is given of various technologies for the production of fibrillating and network-forming marine collagens, which do not cover processing of secondary placental raw materials. A generalized functional scheme for the production of soluble collagen has been proposed. And when one specifies it for a particular technology, it is necessary to take into account physicochemical characteristics of the raw material and the specific type of the extracted protein. The existing directions of the collagen use in the cosmetic industry have been considered, associated with its biocompatibility, biodegradability, biomimetic and hemostatic properties. Among the spectrum of possible cosmetic preparations, anti-aging protection, softening and increasing the elasticity of the skin, analgesic and regenerating effect, protection from UV radiation, restoration of the hair structure and strengthening of the nail bed have been noted. Samples of commercial forms of cosmetics based on the marine placental collagen and other native components of roe extracted from secondary raw materials have been proposed. The volunteers did not have any negative effects after using the cosmetic preparations developed by us. A synergistic effect is predicted with the joint use of collagen types I and V. The ecological aspect of the production of marine placental collagen has been mentioned.

Analysis of graphoanalytical and analytical methods for determining reactions in kinematic pairs of single-moving mechanisms has been carried out. The graphoanalytic method is characterized by clarity. Its application involves repeated reproduction of a number of actions. Analytical methods are based on the compilation of equilibrium equations for a single link or for a structural group of the mechanism. These methods are used, as a rule, to assess the effect of the useful resistance force and the change in the transmission angle on the values of reactions in pairs of single-moving mechanisms. In order to evaluate the effects of the gravity forces of the links and the variation of the transmission angle on the values of forces in pairs of a single-moving mechanism, a method for determining reactions in such pairs has been developed. The practical application of the method involves the synchronous use of AutoCAD and Mathcad programs. The difference between the method and the well-known graphoanalytic method is as follows. A polygon of forces is not constructed for the L.V. Assur structural group, angles are measured directly on this group. So, the angles between the lines of gravity of the connecting rod, rocker arm and the direction of the tangential components of the reactions in the crank-connecting rod and rocker-rack pairs are measured, respectively. In relation to the structural group of M. Z. Kolovsky, a triangle of forces is constructed and the value of the angle between the line of gravity of the crank and the direction of the full reaction in the crank-connecting rod pair is set. The total reactions in pairs of a single-moving mechanism are maximal in the position when the transmission angle is minimal. In this position of the mechanism, the crank continues the line of centers. The reaction in the connecting rod-rocker pair, unlike the forces in other pairs, increases both with an increase in the transmission angle and with its decrease.

Trawl fishing vessels for working with fishing gear have fishing schemes, which include commercial winches and cable-net drums. When designing the hulls of fishing vessels, appropriate techniques are used. In turn, there are no methods to develop fishing schemes and complexes with various types of fishing, which leads to a low level of mechanization of operations and, as a result, to significant production costs. For this reason, schemes and complexes in industrial fishing are often designed with overestimated capacities and mass-dimensional characteristics. This circumstance ultimately affects profitability of trawlers and fish products cost. In most cases, development of fishing complexes for trawlers is carried out according to the prototype, taking into account their size. In accordance with the foregoing, this work is devoted to establishing links between the energy characteristics of fishing equipment and vessel parameters, in order to obtain initial data for the development of methods for designing complexes and schemes. To solve this problem, a review and analysis of fishing schemes for fishing trawlers with main engine powers from 44 kW to 5300 kW has been carried out. The main factor of the analysis was comparison of the given power parameters of fishing winches and power characteristics of fishing vessels. Based on the results of the study, the dependences of the power characteristics on the power of the power plants of the trawlers have been established analytically. Regressions are presented in the form of graphs and written by mathematical formulas, for which their adequacy has been checked. The results of the study will find application in the development of fishing complexes for fishing vessels.

Additive technologies are currently being actively implemented at the enterprises of the shipbuilding industry. After the successful testing of fused deposition modeling (FDM), stereolithography (SLA) and multi jet modeling (MJM) technologies in terms of prototyping and production of polymer products, the general vector of development seeks to master the technologies of metal printing of blanks and finished parts. Work in this direction is being carried out at a number of enterprises and the most popular technologies in this aspect are selective laser melting (SLM), wire arc additive manufacturing (WAAM) and high-speed direct laser deposition (HSDLD). At the moment, the interest of a number of shipbuilding companies is the possibility of producing blanks for parts according to castings drawings using the SLM technology. However, it should be noted that in the literature there are conflicting data on the properties of the samples obtained, in particular, regarding the presence of anisotropy of strength characteristics and the compliance of geometric deviations with existing standards. It is interesting in this regard to manufacture products of complex geometry from stainless steels, which can be used in the manufacture of levers, forks, housings of special equipment, as well as supercavitating screws and elements of hydrofoil consoles for small vessels. This paper describes the physicomechanical characteristics and geometric deviations of samples obtained by the SLM technology on a Laser Cusing M2 setup made of 316L stainless steel. Specific ideas are given about the anisotropy of strength properties and the compliance of the geometry of the samples with the requirements for the manufactured products. The presented materials can serve as a starting point for carrying out strength calculations of products, taking into account some specifics of additive technologies and, in particular, the SLM process.

Classification of vessels is carried out on various grounds: depending on their purpose, dimensions, deadweight, operational restrictions, principles of buoyancy, transported goods and methods of their handling. Vessels of the oil and gas fleet traditionally belong to the group of vessels of the "technical fleet", designed to ensure the development of offshore fields on the continental shelf, to perform underwater technical, down hole, construction and installation, pipe-laying and cable-laying works, as well as other tasks related to the operation of oil and gas facilities. The continental shelf is the most accessible part of the World Ocean and is the zone of the most active human activity in the development of various resources. Development of the World Ocean is aimed at solving three main problems that are of paramount importance for the further global development of mankind: an increase in the volume of extraction of mineral raw materials, use of ocean energy, provision of food and accommodation of the population. The article examines the various views of modern society on the classification of ships and ocean engineering facilities, with the help of which a set of measures aimed at the development, construction and operation of various energy facilities of the continental shelf is implemented. In particular, the article analyzes the classification principles of the Russian Maritime Register of Shipping, the Norwegian DNV (Det Norske Veritas), as well as classification approaches used by oil and gas companies and brokers (on the example of Rystad Energy, Norway). In addition, the article in the form of tables and diagrams presents generalized data on the classification of the oil and gas fleet used in various periods in the domestic oil and gas industry.

The aim of the work is to analyze a Roadmap of the Marinet track of the National Technology Initiative and develop proposals for its updating in the context of the new situation in the world bifurcation of the world system caused by the economic war between developed Western countries, with the United States ahead of the game, and Russia. The Marinet road map has been analyzed, the necessity of including production technologies for deep processing of marine bioproducts, recycling, accelerated development of domestic fishing shipbuilding, equipment and materials, aqua and mariculture, renewable marine energy with simultaneous accelerated digitalization of the marine economy has been substantiated. Digitalization of the maritime economy should be carried out by creating independent digital ecosystems using domestic digital platforms and software products, the element base of microelectronics, sensors and computer technology, expanding and improving training of digital economy personnel. Digital ecosystems, going beyond the maritime economy and spreading to other industries, ensure the implementation of the “strategy of adjacent synergistic development”. It is shown that the focus of development should be the classical innovative model of the economy with the priority of developing new production technologies, relying on internal sources of investment in production, modernizing public-private partnerships and training systems for professional personnel in the digital economy. Creation of digital system designers and development of algorithms that ensure rapid construction and congruent restructuring of digital ecosystems, depending on changes in the internal and external environment, will ensure the accelerated digitalization of the Russian economy, its digital and technological sovereignty. For the coastal regions of the country, the need for the synchronous development of agro-industrial and fishery complexes, public catering enterprises in the concept of a full-cycle bioeconomy is shown. The use of digital platforms significantly reduces food prices, increases food security and sustainability of regional development.