Objective: to review the current state of the red king crab stocks in the Barents Sea off the coast of the Kola Peninsula and propose options for optimizing their use.

Method: the work is a review of the state of stocks, biology and fishing regime of the red king crab in the Barents Sea coast, based on previously published research results. In addition, unpublished survey data with appropriate explanations were used.

Novelty: the review contains information relevant for the summer of 2023 on the fishing regime of the red king crab in coastal waters, examines the prospects for the exploitation of stock of king crab in connection with changes in legislation that occurred in 2023.

Results: the coast of the southern part of the Barents Sea is of high importance for the reproduction of the red king crab population and can be considered as a reserve for its fishing in the EEZ of Russia. Among all the sections of the Barents Sea coast, Varanger-Fjord, as the most remote from the area of modern fishing area, is promising for the resumption of crab production in it. In addition, fishery the red king crab in the western part of coast of the Barents Sea will provide additional data on the impact of fishing on the stock, which will be used in fisheries management. In the near future, it is advisable to consider the possibility of changing the by-catch limit for non-commercial individuals when mining in the coastal area, as well as the possibility of allocating the Varanger-Fjord the red king crab as a separate management unit within a single reserve. Prior to receiving new data, it is possible to recommend that no more than 0.6 thousand tons of the red king crab in the Varanger-Fjord area.

The purpose of the work: to give a biological characteristic of the Pacific halibut in different areas of the Bering Sea and off the eastern coast of Kamchatka and to analyze its size age composition in catches of trawl fishing. Methods used: the material was collected during the expedition research, a complete biological analysis of the Pacific halibut was carried out, the otoliths were selected to determine the age. The age was determined in accordance with the guidelines developed specifically for the Pacific halibut in the International Commission on Pacific Halibut (International Pacific Halibut Commission, IPHC).

Novelty: the elements of novelty are generalized and analyzed data on Pacific halibut. The material collected in the waters of Eastern Kamchatka and the Bering Sea in 2022. Pacific halibut from trawl catches have been studied, its biological characteristics have been considered, the size-age composition and growth rate have been analyzed.

Practical significance: the results of these studies can be used in forecasting the stocks of Pacific halibut in this area.

Result: data on catches of Pacific halibut in different regions of the North West Pacific Ocean, the size and age composition, a comparative characteristic of males and females by growth rate, the age composition of fish by maturity stages.

The purpose of the work is to present data for the last 15 years and analyze the fecundity of pink salmon at the present stage of its natural and hatchery reproduction on the island Iturup.

The research material was based on the results of biological analysis of pink salmon breeders running to spawn in the basins of Prostor and Kurilsky bays (Iturup Island, Sakhalin region) in July-September 2008–2022. Methods used: standard methods of biological analysis, descriptive statistics methods.

Results: it was established that over the past 15 years there has been a trend towards a decrease in the weight of female pink salmon. The value of absolute fecundity during this period varied from 289 to 3568 oocytes, and on average, with one exception, ranged from 1277 to 1640 oocytes. Fecundity was positively but weakly correlated with the length and weight of females within each of the annual samples, and the reliability of this relationship was achieved due to the volume of the samples. The relationship between the fecundity and weight was stronger than that between the fecundity and the length of fish. Average fecundity values were closely correlated with the average weight of females, and, therefore, as in the case of fish weight, in the period from 2008 to 2022 there was a trend toward a decrease in average fecundity values.

Practical significance: we studied the fertility of female pink salmon from the only large commercial stock in Russia, formed through natural and hatchery reproduction.

The aim of the work is assessment of the spatial and density distribution of Pacific herring Clupea pallasii off the southeastern Sakhalin in June-October.

Material and methods. It is based on the data of the 1989–2020 bottom trawl surveys.

Novelty. For the first time long-term data on the spatial distribution of herring off the southeastern coast of Sakhalin Island are presented from the bottom trawl surveys.

Results. Off the southeastern coast of Sakhalin Island herring is found in June in a pre-spawning state at depth of up to 140 m, concentrating abeam the spawning grounds. In July-October, during the feeding period and the initial period of wintering migration, herring spreads almost exclusively at depths of up to 50 m at a water temperature of more than 2–4 °C within the boundaries of the cold intermediate layer, forming the main accumulations in the Terpenya Bay at depths up to 30 m.

Practical significance. The data complement the information on the spatial distribution of herring off the southeastern coast of Sakhalin Island in the summer and early autumn, and can be used for making decisions on the rational exploitation of the resource and organizations of trawl surveys.

The aim of the paper is to identify the features of distribution of cetaceans in ice-free areas of the Barents Sea and adjacent waters in August-November and to characterize their habitat conditions (abiotic factors, distribution relative to mass fish species and macroplankton).

The material of the study was the data collected by the Polar branch of VNIRO during the joint RussianNorwegian ecosystem surveys.

Methods: geoprocessing and mapping of the studied parameters, comparative and statistical (principal component and correlation) analysis of the data.

Results: Cetaceans were mainly observed in the western Barents Sea and distributed in waters with depths of from 23 to 2294 m, at temperatures of –1.9…10.7 °C and salinities of 33.0–35.2, the weighted averages of these parameters were 265 m, 3.1 °C and 34.7 respectively. Minke whales, fin whales, humpback whales, whitebeaked dolphins, killer whales, and porpoises were observed in waters with wide ranges of temperature and salinity, while blue whales and sperm whales were observed in waters with narrow ranges of these parameters. The lowest weighted average water temperature (0.3 °C) and salinity (34.4) were typical of humpback whale. Minke whale, fin whale, humpback whale and white-beaked dolphin had the largest overlap in their distribution with that of possible preys. Statistical analysis showed that priority preys for these cetaceans could be capelin and polar cod for the studied period. In addition, one of the possible preys for baleen whales was also macroplankton, and for the white-beaked dolphin — cod, blue whiting and redfishes.

Practical significance: The results of this study can be used in studying the ecology of cetaceans in the Barents Sea, in assessing their impact on stocks of commercial fish species, as well as in ecosystem modeling.

Aim: the generalization of long-term results of a study of the Ahnfeltia formation and the species composition and distribution of the macrophytes in Izmena Bay (Kunashir Island).

Method: data analysis was carried out on the basis of data obtained in 1989–2019 according on recommended methods of fisheries research.

Novelty: data on the state of the Ahnfeltia formation and the species composition and distribution of macrophytes in Izmena Bay of Kunashir.

Result: Since 2014, there has been a decrease in all parameters of the Ahnfeltia field: average layer height, biomass, total area and field reserve. The decline was particularly significant in 2019. The likely reason is fishing in the center of the field with fracturing against the backdrop of a general decline in the stock. In despit of a fairly significant species composition of macrophytes in the Izmena Bay, except for two species of sea grasses, in 1989–2019, most often, 3 types of algae are found — Chondrus armatus, Chorda asiatica and Chaetomorpha linum, which form settlements of varying densities. The general list of macrophytes found includes 79 species. Of these, more than 40 species are facultative epiphytes.

Practical significance: The results will be used to make recommendations for the sustainable use of the commercial seaweed Ahnfeltia fastigiata var.tobuchiensis.

Based on the results of generalization of long-term data on the volume of industrial fishing in freshwater bodies of Russia for 2014–2023, a comprehensive analysis of the state of industrial fishing for the period under review was carried out.

The purpose of the work is to analyze the dynamics of quantitative indicators and the qualitative composition of commercial catches in freshwater bodies of Russia.

Methods used: official annual data on the volume of industrial fish catch in freshwater bodies of Russia for 2014–2023 received from the territorial departments of Rosrybolovstvo were processed in accordance with modern statistical accounting standards.

Novelty: new data on the state of industrial fishing in freshwater bodies of Russia for 2014–2023 are summarized and analyzed.

According to the results of the analysis, it was found that there was a significant increase in industrial catch (by 3–10 times) in freshwater bodies of Russia in the period from 2014 to 2023, it was observed only in the water bodies of the West Siberian fisheries basin, mainly due to more intensive exploitation of reserves of the raw material base of small–scale species in the lake fund of the region. The remaining fisheries basins have been characterized by stagnation of catch over the past ten years, and in some basins (Western) there is a tendency to decrease it. The trend of decreasing the volume of catch of valuable fishing objects (primarily long-cycle whitefish species) has not changed over the described period, their share in the rivers of the ObIrtysh and Yenisei basins continues to decrease.

Practical significance: the results of the analysis of industrial fishing in freshwater bodies of Russia for 2014– 2023 at the present stage of research allow us to assess the prospects for the development of the freshwater component of the fisheries complex in certain regions, identify problems related to the development of fishing on rivers, lakes and reservoirs and work out ways to solve them.

The aim: assessment of the state of populations of anadromous sturgeon in the Sea of Azov, the efficiency of their reproduction and the possibility for the existence of populations in the medium term until 2030–2040. Methods: the calculation of the biomass and population size of sturgeon in the Sea of Azov was carried out using the direct counting method and a modified cohort solution of the Baranov equation. 18and 25-meter bottom trawls were used as standard fishing gear. The assessment of the number of juvenile sturgeon in the Don River was carried out with 3and 2-meter beam-trawls. Molecular genetic methods for the analysis of microsatellite loci and sequencing of a fragment of the control region of mitochondrial DNA were used.

Novelty: materials are presented on natural reproduction of sturgeon in the Don River after flow regulation, and the rate of decline in the survival rate of generations of Russian sturgeon and stellate sturgeon under the influence of illegal fishing is shown. Based on the results of a study of the genotypes of Russian sturgeon individuals, migrations sturgeon from Azov to the Black Sea, as well as Black Sea populations to the Sea of Azov, were confirmed.

Results: an analysis of the dynamics and current state of anadromous sturgeon in the Sea of Azov is presented under the conditions of anthropogenic transformation of their habitat, loss of natural reproduction and climate-related fluctuations in the salinity of the sea waters. A retrospective overview of their commercial use from the mid-19th century to the present is given. The prospects for restoring commercial stocks of sturgeon fish are considered.

Practical significance: the possibility of restoring commercial stocks of sturgeon in modern conditions is shown by increasing the number of released juveniles and increasing the effectiveness of fish conservation measures to a level of more than 90 thousand tons and creating an commercial population of sturgeon in the Sea of Azov.

The aim of this article: to assess the flounder stock state in the 26+28 ICES subdivisions of the Baltic Sea and forecast its catch in the Russian part of the 26th ICES subdivision using non-model methods.

Methods used: The qualitative condition of the stock was assessed by length (LBI method — Length Based Indicators). To develop catch recommendations for flounder stock in 26+28 ICES subdivision, as well as in the Russian sea area, was used an approach for a stock category 3 (ICES classification), based on a combined biomass index for fish from bottom trawl surveys. The assessment was based on the ratio of the average values of population indices of the last two years to the previous values for three years. All methods have been successfully tested at the international level within the framework of seminars and Working Groups of the International Council for the Exploration of the Seas (ICES), in which Russian specialists took part.

Novelty: In conditions of insufficient completeness and quality of available information to justification the flounder catch, using models of the exploited stock, for the Russian water area of the 26th ICES subdivision of the Baltic Sea, non-model methods for assessing the state and predicting its catch were used for the first time. Result: to solve problems of rational management and conservation of fish stocks, the LBI method, as a non-model assessment tool, allows timely identification of qualitative changes occurring in the stock. The flounder stock is within biologically safe limits. The fishery is aimed at preserving small and large fish (conservation option), the stock is exploited optimally. It is possible to maintain the species’ production level at least at the current level.

Practical significance: In modern conditions the current level of information support for forecasting the flounder stock state and catch in the Baltic Sea will make it possible to solve problems related to the management of this resource in the near future.

The aim of the work: forming technological scheme and biotechnical indices of industrial cultivation of Australian redclaw crayfish Cherax quadricarinatus juveniles under controlled conditions based on a generalization of available research investigations.

Used methods: the study was carried out on the basis of the aquarium room of Invertebrate Aquaculture Department of VNIRO on Australian redclaw crayfish juveniles and adults in the period from 2010 till 2023. Standard methods were used to determine hydrochemical parameters and fish-cultural and biological indicators of individuals. Studies were carried out on the characteristics of the life cycle, early stages of development, physiology and nutrition. The data was processed using statistical methods.

Novelty: A technological scheme and biotechnical indicators of industrial rearing under RAS conditions have been formulated for Australian redclaw crayfish juveniles.

Results: A technological scheme and biotechnical indicators for cultivation of Australian redclaw crayfish juveniles have been developed for a modular basin complex. The technological scheme includes six stages: “Selection and housing of brood stock” (1); “Mating and obtaining gravid females” (2); “Maintenance of females with eggs and early juveniles” (3); “Ongrowing of juveniles to 0.2–0.8 g” (4); “Ongrowing of juveniles from 0.2–0.8 g to 2–5 g” (5); “Ongrowing of juveniles for broodstock remount” (6). The success of stages 1 and 2 depends on the spawners’ physiological state, which is determined by the housing conditions during the preparation of crayfish for mating. Stages 3–6 require the use of single-type basins, specialization of which is achieved through the installation of sedimentation tanks for holding females with eggs, shelters and volume-structuring substrates of different types.

Practical significance: application of the proposed biotechnical methods and approaches to the production and cultivation of juvenile Australian redclaw crayfish will optimize the cultivation of the species, which will be beneficial for the development of its cultivation in fish farms.

The aim: establish the possibility of keeping and growing in sea water with a salinity of more than 18‰ of different age groups of bester on marine fish farms. To investigate the body coloration of the breeders and offspring of the Bester hybrid.

Methods used: the research was carried out in 2004–2005 in the Republic of Korea according to standard methods used in fisheries research.

Novelty: data were obtained on the transfer of juveniles and yearlings of Bester to the sea water with a salinity of 28–29‰. Research confirmed the fundamental possibility, as well as the prospects for rearing juvenile bester in freshwater recirculating systems with the subsequent transfer of fish to sea water. Various bester’s shades of skin color are described.

Result: as a result, the average weights of bester juveniles were established to start the transition to salt water. Analysis of the data showed that yearlings switch to a high salinity of 23–24‰ with a survival rate of more than 73%, and juveniles with low survival rate after 18‰. Ten Bester lines were identified, differing in skin color and fin shape.

Practical significance: the experiment already has practical results in the Republic of Korea. Having sufficient resources of salty waters (the Baltic, Black, Caspian and Azov Seas), Russia has prerequisites for the successful cultivation of sturgeon in sea water. The connection of the offspring’s body color and its mother has been established, as well as its diversity depending on the places where sturgeons are cultivating.

The aim of this work is to assess the impact of trout farms on the ecological state of a freshwater body (Lake Ladoga) using hydrobiological parameters.

The main methods of the study were sampling and processing of bacterioplankton, zooplankton, benthos; calculation of abundance and biomass of hydrobionts; analysis of taxonomic structure, species determinations, following standard procedures used in hydrobiology.

As a result, a change in the quantitative development of bacterioand zooplankton, macroand meiobenthos communities, change in structure, simplification of taxonomic composition, decrease in species richness, appearance of species-indicators of toxic pollution in zooplankton and benthos communities under cages in the zones of influence of trout farms was revealed. Differences in the degree of severity of negative impact at the studied farms were noted, which can be attributed to the hydrodynamic factor, since one of the farms is located in conditions of greater flow compared to the other. Environmental quality assessment of planktonic and benthic communities showed the presence of negative impact of trout farms, the extent of which depends on the location of the farm and the degree of flow in the water area where the cages are located.

The aim of the paper is to characterize the features of changes in environmental conditions in various regions of the North Atlantic and West Arctic over the past 40 years.

The material for the study was oceanographic data obtained during surveys in the Barents Sea by the Polar branch of VNIRO. In addition, other available information on hydrometeorological conditions of the North Atlantic and West Arctic in 1981–2022 was used.

Methods of descriptive statistics as well as comparative, correlation and spectral analyses were applied.

Results: In the paper, changes in annual mean air and sea surface temperatures, ice extent, heat content of water masses, and storm activity in the Barents, Norwegian, Irminger, Kara seas, the Rockall Bank, and the Northwest Atlantic are analyzed over the last 40-year period. It is shown that there have been an increasing trend in air and water temperatures and a decreasing trend in ice extent in the North Atlantic and West Arctic since the early 1980s, against the background of increasing storm activity. The trends have been most clearly seen since the beginning of the 21st century. At the same time, variability in air and water temperatures as well as in ice extent and storm activity has a cyclical character. It is noted that there have been a cooling tendency in air and water temperatures and an increasing one in ice extent in the Barents and Norwegian seas since 2016.

Practical significance: The obtained results are useful for better understanding the climatic processes occurring in the North Atlantic and West Arctic over the past 40 years and can be used to assess the influence of climate changes on the main objects of Russian fisheries in these regions.

The purpose of the work is to collect fishing and statistical information and assess the biological condition of the main commercial crab species in the northwestern part of the Sea of Okhotsk in the summer.

Material and methods. The crab fishery was monitored on July 6–26, 2023. The main objects of study were of the red king crab (Paralithodes camtschaticus) in the Ayano-Shantarsky area (I) at depths of 53–92 m and the snow crab (Chionoecetes opilio) in the open part of the North part of Okhotsk Sea at depths of 306–170 m (II). Data collection and processing, both of the main species and of crabs from by-catch, was carried out according to standard methods adopted in fisheries research.

Results. Biological parameters describing the biological state of crabs in the summer season are given for all crabs noted in the catches. For the mass species of crabs observed in catches, fishing and statistical information on functional groups is presented. In the Northern part of the Sea of Okhotsk, landfill 1 is the main area of P. camtschaticus withdrawal with a high level of its abundance and a stable fishing stock. The blue king crab (P. platypus) was often found in by-catch at landfill 1, it has significant fishing potential for the catch areas. The fishing stock of C. opilio in the catch area (landfill — 2) is in satisfactory condition.

Practical significance. Fishery and biological information on P. camtschaticus, P. platypus and C. opilio will be included in the prognostic materials for establishing the total allowable catches in the northwestern part of the Sea of Okhotsk.

The purpose: getting up-to-date information about the summer anadromous migration in 2023 and the qualitative indicators of Pacific salmon in the Sakhalin Bay (Khabarovsk Territory).

Methods used: the work was carried out in accordance with the methods generally accepted in fisheries research.

Result: Up-to-date information about the beginning of spawning approaches of pink salmon and chum salmon in the Sakhalin Bay has been obtained. The number of fishing areas and the dynamics of pink salmon catch in the southern, central and northern parts of the Sakhalin Bay are indicated. It is noted that the commercially significant approaches of pink salmon began from the southern part of the bay. The main biological characteristics of pink salmon and chum salmon suitable for the rivers of the Sakhalin Gulf in 2023 are given.

Practical significance: Information on the migration of Pacific salmon in the Sakhalin Bay and their qualitative indicators will be used in the preparation of materials justifying the projected catch volumes in subsequent years, as well as in the regulation of Pacific salmon fishing in the Sakhalin Bay area.

The purpose: formation of scientific foundations for improving the efficiency of salmon management on Kunashir Island (South Kuril zone) to ensure the sustainable exploitation of the commercial stock of Pacific salmon, maintain the necessary level of their reproduction, preserve the habitat, as well as improve scientific approaches to forecasting commercial catches.

Methods used: the work was carried out in accordance with the methods generally accepted in fisheries research.

Result: information was obtained on the dynamics of Pacific salmon entry, the filling of spawning grounds and the state of reservoirs on Kunashir Island. The collection of materials characterizing the biological indicators of chum salmon producers was carried out. Statistical information was obtained on catches of chum salmon and artificial reproduction of salmon fish on Kunashir Island.

Practical significance: information on the filling of the spawning grounds of Pacific salmon on Kunashir Island and the quality indicators of their producers will be used to substantiate fishing regulation measures. Data on the state of artificial and natural reproduction of Pacific salmon are intended to develop a strategy for the development of artificial reproduction on Kunashir Island.

The purpose: The main goal of the work is to study the conditions of migration of juveniles on the control Savushkina River and describe the state of Pacific salmon migrating off the coast of the Paramushir Island in 2023.

Methods used: Research work was carried out using standard generally accepted methods.

Result: During the research work, data were obtained on the timing and dynamics of migration of juvenile Pacific salmon. The results of monitoring the approaches of Pacific salmon producers are presented. Shown are data on the size-mass characteristics and age composition of chum salmon, sockeye salmon, coho salmon and pink salmon.

Practical significance: The results of the research work carried out will be used in the preparation of materials for the projected volume of production (catch) of Pacific salmon for 2024 and subsequent years for the North Kuril subzone.

The goal of the work: to assess the current state of the Pacific walrus population and other marine mammal species in the Chukchi Sea subzone (the area of the Natural sanctuary «Cape Vankarem»).

Problems: obtaining new information about the number, sex and age structure, reproduction rates of walruses in the research area; assessment of the timing and intensity of filling the local rookery; assessment of the level of coastal mortality of marine mammals, age and sex composition of fallen animals; assessment of anxiety factors and the level of their impact on animals; collection of meteorological data in the research area during the research period; scientific support of aboriginal fishing; data collection on other marine mammal species in the research area (cetaceans, real seals); accounting of the number of predators (white and brown bears, killer whales) in the vicinity of the rookery and monitoring their relationship with walruses.

Scientific work on the coastal walrus rookery was carried out in the area of the Cape Vankarem (the Arctic coast of the Chukchi Sea), from August 15 to October 2, 2023.

Practical significance of the research: assessment of the current state of the local grouping of Pacific walruses, the level of natural loss and reproductive ability of the grouping; data for regulating fishing, increasing its efficiency and ensuring the conditions of traditional nature use of the indigenous population of Chukotka.