The purpose of the work: to study the genetic structure and genetic heterogeneity inherent in various beluga populations for the competent construction of the restocking process of the species.
Scientific novelty: for the first time, the results of studying the genetic diversity of mtDNA control region of beluga in its entire range and brood stock of beluga in the SFF of the Caspian region are presented.
Materials and methods: the work uses material from the RNCRGM FGBNU VNIRO (Russian National Collection of Reference Genetic Materials). The mtDNA control region was sequenced using ABI3500xL genetic analyzers (Applied Biosystems, USA). The collection and analysis of fish-breeding and biological indicators, materials on artificial spawning of producers in the period from 2016 to 2021 was carried out, the effectiveness of crosses was assessed by the degree of development of eggs at the stage of 4 blastomeres.
Results: 100 different mitochondrial haplotypes with a length of 614 bp were identified in 246 beluga individuals. The largest number of haplotypes is found in the Caspian population, the smallest in the Azov one. The total haplotypic diversity for beluga was Hd=0.983, standard deviation 0,002, and nucleotide diversity π=0,0138±0,00712. Comparison of populations showed high intra-population and low inter-population variability. There is no genetic differentiation between the beluga populations of the Caspian and Azov Seas, the most pronounced differentiation is between the Caspian and Black Sea belugas. Such fish-breeding and biological characteristics as average weight, inter-spawning interval, relative and working fertility, generative index, and other data were evaluated and entered into the register of beluga producers. It has been shown that the genetic polymorphism of belugas used in SFF to produce juveniles is sufficient for the formation of genetically diverse offspring.
Practical significance: the data are used in genetic monitoring and restocking of the natural beluga population.

Purpose: Determine the relationship between the duration of embryonic and larval development of pink salmon (Oncorhynchus gorbuscha) under different temperature regimes and the timing of downstream migration of their juveniles.
Research Material: Multiyear average daily data on water temperature and condition of pink salmon embryos and larvae bred in commercial volumes at the Kurilsky (Iturup Island), Lesnoy and Pugachevsky (Eastern Sakhalin) salmon hatcheries.
Methods used: Comparative data analysis, descriptive statistics methods.
Results: The known facts about changes in the timing of embryonic development in relation to water temperature were confirmed: The duration of the interval between the dates of hatching of embryos in the first and last batches developed under different thermal conditions was 2.5 times longer than the interval between the dates of fertilization of eggs from these batches. The extension of the embryonic development period in the last batches was accompanied by a shortening of the subsequent development period until the fry were ready to swim, which reduced the difference in the duration of development from egg fertilization to fry swimming at different temperatures. This process is not only associated with different hatching times and slowed development in the winter period. The identified peculiarities in the changes in the duration of intermediate developmental stages under different temperature regimes suggest that fry developing in colder water goes afloat as less developed. Such regulation of the total duration of embryonic and larval development of pink salmon provides mass migration of its juveniles from rivers in the average annual terms of mass development of zooplankton in the coastal sea.
Practical Significance: The presented article is a scientific accompaniment of the monitoring of pink salmon juvenile downstream migration in order to forecast changes in the stocks of this species of Pacific salmon.

The aim of the work is to analyze the results of virological and immunological studies, to track the dynamics of the entry and changes in external signs of pathology of Atlantic salmon into the Kola and Tuloma rivers.
Methods used: fish size and weight indicators were determined using generally accepted methods. Methods for isolating viruses on continuous cell lines and their identification in RT-PCR reaction were used. Bactericidal activity of blood serum (BABS) was assessed using a nephelometric method. The content of non-specific immune complexes (IC) was established using a spectrophotometric method with selective precipitation with PEG-6000.
According to the results of the work, it was revealed that in the Kola and Tuloma rivers, clinical manifestations of pathologies in fish have changed. Since 2021, typical symptoms of UDN have been replaced by signs of «red skin disease». The results of immunological studies indicate high activity of innate humoral immunity mechanisms in the examined individuals. The carriage of infectious pancreatic necrosis virus in Atlantic salmon populations living in the Kola and Tuloma rivers has been established. Clinical signs of pathology in Atlantic salmon are described in detail, and fish counting data for the Kola and Tuloma rivers are presented.
The novelty of the work: for the first time, photographs of all noted typical signs of pathology, as well as the results of virological and immunological studies of Atlantic salmon in the Kola and Tuloma rivers for 2022–2024 are presented. A retrospective overview is given and prospects for studying the problem are outlined.
Practical significance: the conducted research will allow creating a database on the results of comprehensive studies of Atlantic salmon diseases in the Kola and Tuloma rivers. Compare the results obtained in fish with and without clinical signs of pathologies over several years. Determine differences in the immune status of fish with different signs of pathology based on the results of long-term studies. This will help to understand how UDN disease develops over time and what causes it.

Objective: to assess changes in the structure of the modern fishery for sablefish Anoplopoma fimbria in the EEZ of Russia in the context of the growth of its resources and identify prospects for its immediate development.
Methods: in preparing the article, the methodology of analyzing specialized marine fish fishery in the western part of the Bering Sea was used on the basis of data from ship’s daily reports, information from open sources and archival materials were involved. Standard methods of data processing and interpretation were used.
Novelty: the paper analyzes the current structure and intensity of fishing for sablefish in the West Bering Sea zone, considers the prospects for the development of its specialized catch by bottom tiers and traps
Result: тhe analysis of the retrospective and current dynamics of stocks and fishing of sablefish within the range is carried out. The changes in the structure of its catch in the West Bering Sea zone, both specialized and in the form of by-catch, are considered. The trends in the dynamics of fishing indicators against the background of the growth of fishery resources are revealed. The prospects for the near-term development of the fishery are assessed and some recommendations are given regarding its regulation.
Practical significance: the results obtained will be used to develop recommendations and measures to regulate fishing for the rational use of sablefish resources in the West Bering Sea zone.

Objective: Implementation of the concepts of best aquaculture practices as a mechanism for sustainable development ща aquaculture in Russia
Methods: Comparative analytical methods of studying open information sources as well as a semi-quantitative scoring method to determine the degree of impact of risks and threats to the sustainable development of aquaculture farms were used.
Novelty: An analysis of the best practices used in countries with developed aquaculture was conducted, a current list of threats to aquaculture farms in Russian Federation was determined, and principles and criteria for assessing the sustainability of aquaculture farms were proposed.
Result: The basic principles and criteria for the best aquaculture practices for the main areas of Russian aquaculture are formulated, and primary sets of indicators characterizing various aspects of sustainability are developed. The following sustainability aspects were selected: regulatory, environmental, safety, technical and economic. A semi-quantitative threat analysis revealed that the most vulnerable are pond and cage farms, precisely those types of aquaculture farms that contribute the most to the volume of aquaculture production.
The practical significance: The proposed system of criteria allows to assess current threats to Russian aquaculture farms and suggest areas of activity to reduce risks. The system of criteria, after its verification in operating aquaculture farms, will be used in the development of reference books (guidelines) on best aquaculture practices.

The aim: to characterize the Black Sea water temperature influence on the anchovy fishing.
Methods: the assessment is based on long-term data of anchovy catch statistics and oceanographic data on water surface temperature during the period 1992–2023 by the Copernicus marine project. The main hypothesis about the relationship between changes in water temperature and annual catches of European anchovy was carried out by methods of cross-correlation and spatial correlation analysis.
Novelty: statistical analysis of long-term data allowed us to find significant spatio-temporal patterns between parameters of anchovy fishing and changes in water temperature.
Results: a significant positive relationship between anchovy catches in the northwestern part of the Black Sea and the water surface temperature is shown: the average annual (with a lag of 1 year, rs = 0,50) and the average winter (without lag, rs = 0,42) temperature. Positive trends of average annual and average winter sea surface temperatures have been described. There were significant positive spatial correlations between water temperature and anchovy catches in November-February, the most significant in December-January. The areas of spatial correlations between water temperature and anchovy catches increased in period 2008–2021 relative to 1993–2007. The existence of a relationship between the indicator of climate change (water temperature) and fishing parameters in the northwestern part of the Black Sea has been confirmed.
Practical significance: the established long-term correlation patterns between changes in water temperature and the parameters of anchovy fishing in the nortwestern part of the Black Sea allows to increase the efficiency and sustainability of Russian fisheries in these waters.

The aim: to study the amount of cadmium found in muscle tissue and liver of the main commercial fish species of the Barents Sea.
Research material was comprised of fish samples collected during the expeditions of N.M. Knipovich «PINRO» in the Barents Sea in 2009–2021. The study was based on muscle and liver samples taken from cod, haddock, long rough dab, Greenland halibut, plaice and spotted catfish. Over 1500 samples were analyzed.
Novelty: for the first time a comparative analysis of Cd concentration in six commercial fish species of the Barents Sea was run and background readings were provided using such a big amount of data.
Methods used: the content of Cd in fish samples was measured using Shimadzu (Japan) Atomic Absorption Spectrophotometer (AAS). Statistical data processing and charting were done using MS Excel and application software package of Statistica 13.
The results show that the average content of Cd in muscle and liver of the examined fish did not exceed the established sanitary standard for the maximal concentrations of 0.2 and 0.7 mg/kg of wet weight, respectively. No evidence of anthropogenic contamination of the studied species by cadmium was found. The cadmium concentrations in liver was 11–17 times higher than in muscle. The total content of Cd in muscle and liver demonstrated a high variability (dispersion). The main reason for this variability is differences in the diet and feeding habits of the fishes. The cadmium content in muscle tissues is species-specific. The liver is capable of removing Cd from the body actively. The study also found other factors influencing the cadmium concentrations, such as taxonomic affiliation and regional peculiarities (particularly, habitats and fishing areas).
Practical significance: the acquired results were used to determine whether the commercial fishes meet the sanitary standards used in Russia.

The aim. Assessment of the current state of the zoobenthos in the southern part of the Cape Svyatoy settlement of the Iceland scallop in five years after the finish of its commercial exploitation.
Material and methods used. Analyzed material was sampled from the R/V «Professor Boyko» during a resource survey of the Icelandic scallop in the Barents Sea in September 2023. A complete quantitative taxonomic analysis of the Sigsbee trawl bycatches of bottom invertebrates was carried out at 85 stations within twelve-mile zone of the Cape Svyatoy settlement of the Icelandic scallop. Four indices were used for assessment of the macrobenthos ecological quality: Clark’s W-statistic, the predominant life strategy index D_E, AMBI and M-AMBI indices.
The results. The main characteristics of macrozoobenthos in the area of the Cape Svyatoy settlement of the Iceland scallop are described (taxonomic composition, distribution of species richness, diversity, total abundance and biomass, list of the most abundant species, characteristics and distribution of the main bottom communities). The level of average benthic biomass within the study area is estimated as lower than expected given the long preceding warm period. Based on comparison of 2016 and 2023 benthic data, the positive dynamics of the trophic structure of benthos are noted. According to results of bio-testing the ecological state of benthos, in the main part of the study area, is assessed as good and undisturbed, with the exception of area to southeast of Cape Svyatoy, where the lower values of ecological status, abundance and species diversity of benthos are caused by natural environmental conditions.
Practical significance: The results of the study provides insight into the bottom communities’ recovery after intensive fishing pressure.

The purpose of the work is to develop mathematical dependencies of the physical and mechanical characteristics of twisted fishing materials. The creation of a mathematical apparatus for modeling the geometric and force parameters of twisted fishing materials is a priority task for the development of new materials for industrial fishing and aquaculture.
Methods used: Mathematical analysis of the obtained experimental data on the relative elongation and breaking load of fishing materials in order to determine the dependence of the forces on the structural and geometric characteristics of twisted fishing materials.
Novelty: Based on the results of experimental studies, approximating dependences of relative elongation and relative breaking load on the continuity of the product, as well as on the ratio of surface and longitudinal tension of twisted fishing materials made of polyamide, polypropylene and polyester, were obtained for the first time.
Result: Mathematical dependencies make it possible to calculate the relative elongation and breaking load of twisted fishing threads and ropes made of polyamide, polypropylene and polyester within an accuracy of 90%.
Practical significance: Mathematical modeling of the physical and mechanical characteristics of twisted fishing materials allows, when designing industrial fishing tools, to set, taking into account the safety margin, the design characteristics of fishing products that are made of polyamide, polypropylene and polyester.

The aim of the work is to evaluate the assortment structure, analyze the composition, as well as the nutritional value, organoleptic and physicochemical indicators of commercial samples of breaded pollock products, presented in the Russian market. 
Methods used: The analysis and structure of the assortment were determined by means of the calculation method. Data on component composition and nutritional value were analyzed by the method of labeling examination. Standard methods were used to determine sodium chloride and water content. The results of organoleptic evaluation were processed by the method of profile analysis and mathematical method with the use of heuristic approach to the evaluation of product quality indicators. 
Novelty: The main defects, as well as physico-chemical and organoleptic characteristics of the quality of breaded products
Results: The leading place of breaded fish culinary semi-finished products from pollock in the structure of the Russian market among the products of this name from other species of aquatic biological resources is shown. It is revealed that breading systems of commercial samples of breaded pollock products consist mainly of ingredients of low nutritional and biological value. 
Practical significance: the results obtained are used for the development of breaded products with increased nutritional and biological value.

The purpose of the work: to test the hypothesis about the existence of periodically changing price volatility over time and to determine the key characteristics of this process.
Methods used: decomposition of price dynamics for the main types of fish products in Russia with the allocation and analysis of its components; to construct a model describing the trajectory of price changes, the provisions of the spider web theory were used, in particular, the Kagan model, transformed into the harmonic oscillator model.
Results: it was found that prices for fish products in the Russian Federation, in addition to the general upward trend, also have cyclical volatility and are subject to shock changes from time to time; the parameters of price fluctuations were determined.
Scientific novelty: A nonlinear model has been developed that reflects in aggregate form the influence of endogenous and exogenous factors on prices for fish products. The model describes cyclical price changes in the form of relaxation fluctuations.
Practical significance: The study of the recessive characteristics of price volatility made it possible to identify the key parameters of possible measures of industry policy. These measures can become part of the socioeconomic policy.

The purpose: to perform an integrated assessment of the digital transformation of the fisheries complex, to evaluate the capabilities and contribution of the main sectors of the industry economy and fisheries basins in this process.
Methods used: the information base of the study consisted of statistical materials and reports of enterprises on the use of digital technologies. The main methods of the study were the indicator assessment based on the calculations of original subindices and the consolidated index of digital transformation; comparative analysis and comparison with the indicators and indices calculated for the economy as a whole.
Novelty: based on the developed methodology, an analysis of significant areas of digital transformation of the industry was carried out: competence support; infrastructure and financing of digitalization; use of end-to-end technologies of the digital economy; the level of digitalization of production and business processes for the fisheries complex as a whole, as well as for 1) its three sectors: fisheries, fish farming and processing of aquatic biological resources, and 2) fisheries basins.
Result: an integrated assessment of the digital transformation of the fisheries complex, its level in comparison with the general economic one, was obtained. The degree of digitalization and the possibilities of digital transformation for the main sectors of the fisheries economy and each fisheries basin were determined. Brief recommendations for the formation of industry policy and further research were given.
Practical significance: the possibility of wide application of the integrated index of digital transformation for the development of imperatives and adjustment of the industry strategy for digital transformation, as well as subindices and indicators in the analysis of the activities of enterprises in the main sectors of the fisheries economy, taking into account the territorial specifics. The methodology is applicable to any level of the organizational and economic structure of the fisheries complex.

The aim: description of the subspecies of dinophyte algae Ceratium tripos var. balticum, first discovered in the Caspian Sea.
Materials: Monitoring observations of the state of the Caspian ecosystem and the food supply of commercial pelagic fish species: collection of hydrobiological material in the Middle Caspian during a sprout survey in the summer of 2024 on the IS «Caspian Researcher» according to the standard grid of stations adopted by the Volga-Caspian branch of the State Scientific Center of the Russian Federation «VNIRO» («CaspNIRKH»). Phytoplankton samples were collected using a BSR bathometer (4 L), fixed with formalin and concentrated. During laboratory processing of the material, the species composition was determined, and the abundance and biomass of planktonic algae were calculated.
Research results: when processing phytoplankton samples, a representative of the genus Ceratium, which was not found in the Caspian Sea, was discovered.
Scientific novelty: for the first time, a description of a new species of dinophyte algae Ceratium tripos var. balticum (Dinoflagelta: Dinophyceae).
Practical significance: due to the fact that the species is large in size, it is inaccessible to zooplankton phytophages, and since there are no species capable of consuming it as food and thereby limiting its development, its rapid development is possible, which may entail a restructuring of the main connections and energy flows in the ecosystem, as happened when the diatom Pseudosolenia calcar-avis invaded the Caspian Sea.

The aim: the characteristics of the species, size and weight composition of sturgeon fish in the near-shore zone of the Sea of Azov.
Material: bycatch data from scientific monitoring of So-iuy mullet fisheries with stationary seines in the waters of the Temryuk Bay and in the Kerch Strait near the Chushka Spit in April 2024.
Results: sturgeon species were encountered in stationary seines in 100% of cases. The average catch per seine was 2–11 specimens per day. Starry sturgeon in Temryuk Bay accounted for more than 40% of the sturgeon bycatch, but it was not encountered in the Kerch Strait. Beluga Huso huso was noted in the Kerch Strait. The size range of Russian sturgeon varied from 30 cm to 133 cm; Starry sturgeon — from 102 to 118 cm. The average size of Russian sturgeon was 92.1 and 99.8 cm with an average weight of 9.2 and 6.4 kg, respectively, near the Chushka Spit and at the mouth of the Kuban. The average size of Starry sturgeon was 110.1 cm with an average weight of 6.7 kg. The length of the Beluga was 73 and 190 cm. The share of Russian sturgeon of commercial size (>90 cm) near Chushka Spit was 55%, in Temryuk Bay — 79%. 100% individuals of Starry sturgeon at the mouth of the Kuban were of commercially acceptable size (>80 cm).
Practical value: Observations of bycatch in stationary seines in the near-shore zone are the important source of data on the qualitative characteristics of sturgeon populations in the Sea of Azov.

The purpose: the main objective of the work is to study the approaches to pink salmon spawning and filling of spawning grounds in the rivers of the western coast of Aniva Bay on Sakhalin Island (from the Uryum River to the Petrovka River).
Methods used: research work was carried out using standard generally accepted methods.
Result: data on filling of spawning grounds in the rivers of the western coast of Aniva Bay were obtained.
Practical significance: the results of the conducted research work will be used in the preparation of materials for the predicted volume of production (catch) of Pacific salmon for 2025 and subsequent years in the Sakhalin Region.

The purpose: the main objective of the work is to study the state of whitefish populations in the lower reaches of the Kolyma River (Sakha Republic (Yakutia)), as well as monitoring the runs of Pacific salmon (chum salmon, pink salmon).
Methods used: the research work was carried out using standard generally accepted methods.
Result: data were obtained on the size composition and state of the populations of European whitefish, broad whitefish, peled, muksun, sheefish, sardine cisco, as well as pike and burbot. Pacific salmon were not noted during the research period.
Practical significance: the results of the research work will be used in the preparation of a biological justification for determining the volumes of whitefish and Pacific salmon catches in the Kolyma River for 2025 and subsequent years.

The goal of the work: assessment of summer oceanographic conditions of the Barents and Kara Seas.
Materials and methods: the data presented in the work were obtained on the 96rd cruise of the R/V «Akademik Mstislav Keldysh» (July 25, 2024–August 31, 2024). During the expedition, hydrological and chemical characteristics (temperature, salinity, dissolved oxygen, silicates, mineral and organic forms of nitrogen and phosphorus and dissolved organic carbon) were measured from the surface to the bottom. Chemical analysis was carried out in the ship’s laboratory, according to certified methods for sea and fresh waters. Dissolved organic carbon samples were using a filtration through membrane filters (0.45 μn) and fixed with hydrochloric acid for further determination using high-precision TOC–L equipment in a stationary laboratory in Moscow. In total, 13 oceanological sections and 183 complex oceanological stations were completed.
The practical significance of the research: assessment of the production potential of the economically significant seas of the European Arctic for Russia in the area of maximum climate changes, replenishment of the monitoring system of hydrological and biogeochemical characteristics based on ship observations in accordance with the Order of the Government of the Russian Federation of October 29, 2022 No. 3240-r.

The aim: obtain data on the biology, distribution and abundance of the Pacific ocean perch, Atka mackerel, by-catch species, and monitor aquatic biological resources.
The methods: in the course of specialized fishing, fishing information was collected and ichthyological work was carried out according to the generally accepted methodology.
The newness: expeditionary work is a continuation of many years of scientific research on the state of commercial populations of valuable fish species in the western part of the Bering Sea and Eastern Kamchatka and the North Kuril Islands.
Results: concentrations of Pacific perch were noted in the area of Cape Kamchatsky, Cape Kronotsky, and in the area of Shiashkotan and Onekotan islands. The largest catches were recorded at Cape Kronotsky (2.25–5 tons/hour of trawling). The average length of the beaked perch decreased from north to south from 39 cm to 37 cm, weight — from 868 g to 681 g. The main concentrations of the Atka mackerel were noted in the area of Cape Afrika and Cape Kamchatsky (the largest catches are 8–10 tons/hour of trawling), at Kronotsky (5–9 tons/hour trawling) and Shiashkotan Island (15–40 tons/hour trawling). The average length of the Atka mackerel was 38–39.6 cm with a weight of 635–752 g.
The practical significance: the results of this work will be taken into account when developing and updating materials for forecasting the total allowable and recommended catch and recommendations for efficient fishing.