The rivers of the Curonian lagoon basin (the Neman, Skirvite and Matrosovka rivers) are traditional places for commercial and recreational fishing of European smelt for many decades. Since 2020, commercial fishing for European smelt has been carried out on the Deima River and currently there are already four fishing crews fishing here on an ongoing basis. The spawning migration in 2022 to the Deima River lasted for 19 days and it coincided with the migration to the Neman River. In the Deima River during the study period, the ecological (lake) form of European smelt - dwarsmelt - was not identified, which is typical for the main spawning rivers of the Curonian Lagoon. The size structure of the spawning part of European smelt in the Deima River is similar to the Neman and Matrosovka rivers. The dominance of fishes with a length of 13–14 cm at the age of 3–4 years and a slight increase in the average length of fishes were noted. A comparative interannual analysis of the age structure of European smelt showed the transition of the high-yielding generation to an older age group, which is confirmed by data on the weighted average age. In 2022, females dominated the entire spawning migration, with the exception of a leveling off in the sex ratio in the middle of migration. Despite the identified biological characteristics of the European smelt in the Deima River, it is part of a single population of the Curonian Lagoon and from the point of view of managing waterbioresources it can be considered as one unit of the stock. A potential location for organizing commercial fishing in the Vistula Lagoon basin is the Pregolya River, where European smelt is a favorite object of recreational fishing.

The study of the composition, structure and communication between various microorganisms in biofilms is a priority direction of the development of environmental microbiology. Being a part of the biofilms bacteria, fungi, protozoa and other microorganisms become more resistant to the effects of adverse environmental factors. Microorganisms that form biofilms colonize various surfaces, as well as the skin and mucous membranes of animals and humans, acquire antibiotic resistance and resistance to disinfectants. The aim of the work was to assess the effect of various types of syn- thetic surfactants on the composition of biofilms formed on the surface of pig manure effluents. Surfactants are widely used in various industries, including industrial animal husbandry, mainly in the form of detergents and pharmacological preparations. Biofilms were removed from the surface of the manure effluents in compliance with the rules of asepsis and antiseptics 14 days after the start of the experiment. Microbiological studies have shown that the introduction of cationic surfactants, nonionic surfactants and anionactive surfactants leads to a significant transformation of the biofilms microbiota: the prevalence of fungi Aspergillus ssp. and Candida sp. (44.5–55.2%) over gram-positive microorganisms, characteristic of the control variant (81.49%), and the formation of denser biofilms, capable of reducing the processes of gas emission and odor load from manure effluents. Under the influence of surfactants from biofilms, Staphylococcus epidermidis, Lactobacillus ssp. disappeared from the composition of biofilms and Bifidobacterium ssp., and in the variant with anionactive surfactants also Bacteroides sp. and Pseudomonas spp. Clostridium ssp. showed the greatest resistance to surfactants.

The influence of granular product obtained by thermomechanical treatment of municipal sewage sludge on respiratory activity and phytoproductivity of oil-contaminated gray forest soil has been studied. At the biological treatment facilities of the city of Kazan sewage sludge are subjected to thermomechanical treatment, which results in the formation of granules 3–9 mm in size with moisture content of 5–10% (hereinafter referred to as granulate), which are sufficiently resistant to moisture and mechanical impact. Granulate is certified and is actually a complex, organomineral fertilizer, with the potential ability to stimulate microbiological processes, intensification of plant growth on degraded and contaminated soils. The application of granulate (organic matter – 60.4 %, N total – 3.0 %, N total – 1.5 %, hazard class IV) stimulates respiratory activity, increases the efficiency of oil products destruction, increases phytoproductivity of plants, which indicates the possibility of its application in biological remediation of oil-contaminated soil. The observed decrease of microbial respiration coefficient in the presence of granulate reflects the increase of soil microorganisms resistance to oil pollution. Comparison of the studied approaches demonstrated higher efficiency of destruction of high concentrations of petroleum products in gray forest soil under biological remediation as compared to technical remediation. Technical reclamation of soil in the range of petroleum products content of 2.7–19.7 g/kg, presupposing moistening and mixing, had little effect on respiratory activity and plant productivity, while in the variant containing 2.7 g/kg the efficiency of pollutant degradation was higher than in the experiments with granulate. When carrying out reclamation measures on soil samples with high content of oil products, application of SS granulate at the rate of 10 t/ha increases the efficiency of their destruction.

In a number of countries, avoiding gluten has recently become a fashionable trend, but this trend of eating gluten-free products has a reasonable basis associated with the autoimmune hereditary disease - celiac disease. With this disease, gluten causes a special reaction in the body, as a result of which the absorption and digestibility of nutrients from foods is impaired. One of the possible directions for creating gluten-free products or products with a reduced gluten content is the development of test semi-finished products, for example dumplings, based on gluten-free dough containing gluten protein. The article discusses the possibility of using, from the point of view of sanitary and microbiological safety indicators, industrially produced separated frozen minced aquaculture salmon as a filling for dumplings. Scientific research has determined that, based on dough with reduced gluten content, it is possible to produce fish dumplings based on minced salmon obtained by separating food waste after cutting fish. It has been found that the majority of respondents would prefer new products in their diet made from raw materials that do not contain gluten or have reduced gluten content, as well as those made using minced fish as a filling. Based on organoleptic and micro- biological studies, recommended shelf life for fish dumplings using gluten-free vegetable raw materials stuffed with minced salmon has been established. A structural techno- logical scheme has been developed for the production of fish dumplings using gluten- free dough stuffed with minced salmon.

The results of a study of the effect on the indicators of minced meat of a vegetable additive used to obtain a combined minced meat functional product with a reduced glycemic load are presented. Combined products based on meat and vegetable raw materials include minced meat semi-finished products (cutlets). Combining meat raw materials with vegetable raw materials, which have functional properties and have a low glycemic index, allows you to create products suitable for nutrition of patients with diabetes mellitus or for consumption in order to prevent this disease. In the experiments, a mixture of grade 2 veneered beef, semi-fat veneered pork and pork fat in a certain ra- tio was used as meat raw materials, jerusalem artichoke powder was used as a vegetable additive instead of wheat bread used in the manufacture of cutlets. Jerusalem artichoke powder was hydrated at a ratio of 1:2 with water at a temperature of 60 ° C. The raw meat crushed on a spinning top was thoroughly mixed with hydrated jerusalem arti- choke powder, the amount of which was changed from 5 to 25%. The control was minced meat without jerusalem artichoke powder. The functional, technological and rheological parameters of combined minced meat intended for the production of minced meat semi-finished products (cutlets) with functional properties in terms of inulin con- tent have been studied. The effect of jerusalem artichoke powder on the ultimate shear stress, adhesion and effective viscosity of the combined minced meat, as well as on its functional and technological properties – moisture-retaining and fat-binding properties. It was found that when 20% hydrated jerusalem artichoke powder is added to minced meat for cutlets, its compliance with the requirements for minced meat for minced meat semi-finished products is ensured according to rheological parameters, functional and technological properties and organoleptic characteristics, Replacing wheat bread with jerusalem artichoke powder reduces the glycemic load of the product.

Currently, agricultural enterprises specializing in the production of non-traditional types of milk, except cow's milk, face the lack of personalized information on each type of milk, depending on the type of agricultural animals in the technical regulations. The study of the regulatory framework governing the safety of food products (in particular milk) shows the presence of discrepancies in technical regulations and standards, which determined the purpose of the study to quantify safety indicators, in particular microbiological, and identification indicators of raw mare's milk, close in composition to female milk, having high immunomodulatory properties and related to dairy raw materials for the production of healthy food products of therapeutic and preventive direction from it and for the use as nutritional support according to the established protocol. The need for technical regulation of raw mare's milk as a separate type of dairy raw materials is due to the distinctive identification features of mare's milk from traditional cow's milk and the possibility of entering the consumer market of producers of mare's milk, which requires ensuring the safety of raw materials and products of its processing. An important point is not to allow species falsification by the more common cheap cow's milk. It has been established that TR CU 021/2011 extends its effect to milk without isolation of milk types. A number of indicators are identical in TR CU 033/2013 and in GOST R 52973-2008. Along with this, in TR CU 033/2013, the regulated maximum threshold number of somatic cells is 3.75 times greater than in GOST R 52973-2008. In the standard, the acidity index is differentiated based on sub- sequent use: for children's and therapeutic nutrition – 5 ° T and for the production of koumiss and milk powder – 6 ° T, which is technologically more appropriate. It is necessary to update the current regulatory framework.

Currently, two main forms of fishing are widely known – autonomous and distant-water. The distant-water form of conducting research was popular during the Soviet Union. However, taking into account the economic changes after the collapse of the USSR, they decided to abandon the distant-water form of fishing, since most of the fishing vessels were transferred to commercial organizations, and floating fish processing bases were very outdated and were decommissioned. Large freezing fishing trawlers (hereinafter LFFT), built during the Soviet era, which are currently in operation, continue to conduct autonomous fishing in remote areas of the Atlantic Ocean and deliver finished products to shore independently. In this paper, the feasibility of returning to the distant-water form of fishing is considered, in which the extraction and processing of fish is carried out by vessels of the LFFT type, and the delivery of finished products to shore is carried out by transport refrigerators (hereinafter TR). To determine the feasibility of using TR, it is necessary to evaluate the economic indicators of LFFT in an autonomous form of production, as well as to consider the economic indicators from the joint operation of LFFT and TR. The Northern Region, the Central Region, and the Southeastern region of the Atlantic Ocean are considered as fishing areas. Murmansk and Kaliningrad are designated as the settlement ports of registry, since foreign ports are closed due to sanctions. The article considers the calculation of economic indicators for conducting autonomous fishing of the LFFT type «Pulkovo Meridian», as well as conducting distant-water fishing by several LFFT with the trans- fer of finished products to the TR type «50 years of the USSR». The economic calculation is performed according to the main indicators of income and expenses of both vessels for one voyage and operational period. Based on the results of the analysis of the calculations performed, the task of designing vessels to ensure the best economic indicators of fishing in the Atlantic Ocean is set.

The paper studies the application of rigid polyvinyl chloride (PVC) as the main material of hulls of small vessels. The paper presents the statistics of application of materials of hulls of small vessels. As of 2019, the number of vessels made of polymeric materials in Russia did not exceed 9%. Out of all polymeric materials, the paper considers in detail application of low-pressure polyethylene (LDPE) and PVC is considered. The main domestic organizations engaged in design and construction of HDPE vessels and examples of their works are given. Physical and mechanical charateristics of HDPE and rigid PVC are compared. On the basis of comparative analysis it is shown that rigid PVC is better than low-pressure polyethylene in many respects from the point of view of physical and mechanical characteristics. The characteristics and properties of rigid polyvinylchloride, limiting its use as the main material of the ship hull, are highlighted. A comparative study of creep behavior of rigid PVC and HDPE specimens has been carried out. The tests have been carried out at forces corresponding to tensile stresses of 5–15 MPa. Each sample has been tested for 2 hours. At the selected design stress values, the HDPE specimens showed pronounced creep, in contrast to the rigid PVC specimens. It has been noted that the creep curve of low-pressure polyethylene samples has a pronounced step form. Examples of methods to reduce toxicity in combustion and improve resistance are presented.

The key issue of the study is to assess the effectiveness of the application of existing automation measures in electrical distribution networks in terms of reliability. The issue becomes relevant due to the constant increase in the duration of power transmission lines in distribution networks, which increases the likelihood of damage and further disconnection of the line from protections. The methods of reducing the time during which the under-discharge of electricity occurs are considered by using automation tools such as selective automatic re-activation and an automatic network restoration system (FLISR). The article calculates the main reliability indicators for the use of an automatic network restoration system and selective automatic re-activation using the example of a real 15 kV network section. A section of the distribution network of the Kaliningrad region, including two power transmission lines, was selected as the object of research. Calculations were carried out for three network configuration options: a section of the network in its existing form without modernization; a section of the network using only FLISR; a section of the network using FLISR and selective automatic re-activation system together. The Ministry of Energy's methodology was used to determine indicative reliability indicators. A comparative assessment of the SAIDI, SAIFI and CAIDI indicators was carried out for the three network configuration options described above. The implementation of the proposed network automation measures provides a significant reduction in the average duration of outages and, to a lesser extent, the average frequency of power line outages. The greatest contribution to the reduction of indicative reliability indicators is made by the use of selective automatic reactivation system. So, an assessment of the effectiveness of introducing FLISR and selective automatic reclosing has been carried out in order to achieve the target values for indicative indicators of the reliability of the electrical network.