Results of studies on the relationship between the claw morphometric parameters and the carapace width (CW) of the triangle crab (Chionoecetes angulatus) crab from the Sea of Okhotsk presented. For the operational screening and separation of males into morphometrically mature (ММ - large-clawed) and immature (MI - small-clawed) species, it is proposed to use the coefficient of morphometric maturity (K%). This coefficient can be defined as the ratio of claw height to carapace width (KH%) or as the ratio of claw diagonal to carapace width (KD%), expressed as a percentage. When assessing the coefficient of morphometric maturity (K%), the boundary value for KH% is 16, and for KD% it is 35, which allows reliable identification of large-clawed (MM) males at K% values above the boundary values, and small-clawed (MI) males at K% values below the boundary values. Four functional groups were distinguished in males of C. angulatus: 1) MI physiologically immature - CW <90 mm, KH% <13.5, and KD% <29; 2) MI physiologically mature - CW 90.1-120 mm, KH% 12-16 and KD% 25-35; 3) MI large-sized physiologically sexually mature - CW >120 mm, KH% 13-16 and KD% 29-35; 4) MM morphometrically and functionally mature - CW 74-167 mm, KH% >16 and KD% >35. The correlation of the onset of morphometric maturity with biochemical parameters of hemolymph and with the development of muscle tissue is discussed. For various functional groups of males C. angulatus, an abundance estimate was implemented taking into account the K% coefficient.

The results of the study of macro- (Ca, Mg) and micro- (Mn, Zn, Cu, Fe) elements content in the pectoral fin tissue of adult sockeye salmon Oncorhynchus nerka from the rivers Bolshaya and Kamchatka as well as from Azabachye Lake (Kamchatka Peninsula) are presented. The significant differences in the contents in samples from the three waterbodies were found. It was ascertained that the largest ash proportion (and the mass fraction of trace elements) in dry matter contained in the tissues of sockeye salmon from Kamchatka River, the smallest in the sample of Azabachye Lake. The Ca content was 98% of the ash mass in all samples; Mg accounted for slightly less than 2%. The proportion of the remaining elements varied within 0.1%, and exactly in this range the differences in the microelement composition between the samples were revealed. In sockeye salmon tissues from the Kamchatka River, the content of heavy metals as well as Ca and Mg was higher than in other samples, and their percentage ratio considerably differed from the others. Obviously, the water bodies studied sufficiently distinguish in hydrochemical indices, and that is the cause of differences in bioaccumulation intensities of trace elements in fish tissues at the freshwater life stage.

The article analyzes the data on the size and age composition of mackerel during the sea expeditions on domestic fishing vessels in July-September 2008-2018. The features of the distribution of mackerel in the feeding period of its life cycle are Briefly studied. The information on areas of work of fishing fleet of Russia and features of its dislocation in the specified years is presented. It is noted that the main factors determining the nature of annual migrations, distribution of mackerel and its areas of thought in the Norwegian Sea are the features of the oceanographic situation and conditions of feeding in different years. It is shown that the change in the average length of fish in commercial aggregations is significantly influenced not only by the change of generations, but also by feeding conditions in the years under study, primarily the level of biomass of feed zooplankton in the Norwegian Sea. Distribution of mackerel in the Norwegian Sea in the summer period 2008-2018 confirmed the pattern, which was that large specimens of mackerel were feeding in the North and West of the sea, while small fish - much South and East. Feeding migrations of larger fish were earlier and longer.

Results of studies on nutrition of juvenile fishes of the Curonian Lagoon of the Baltic Sea are presented. Material on young-of-the-years nutrition was collected in October 2016 during the expeditions of «AtlantNIRO» at 14 standard stations in the Curonian Lagoon. A total of 418 specimens of young-of-the-years were collected and processed. Juveniles of fishes of the Curonian Lagoon were represented by 10 species: pikeperch, bream, roach, perch, smelt, ruffe, three-spined stickleback, ninespine stickleback, bleak and sabrefish. Planktonic and benthic invertebrates formed a basis of the young-of-the-years diet. In most species of juvenile fishes, the nutritional spectra did not differ from the nutritional spectra in the range. An exception was juveniles of the ruff and ninespine stickleback, in which planktonic crustaceans predominated in the diet, while in other reservoirs they consumed bottom organisms. Only Cladocera and Copepoda were found in the diet of roach of juveniles; bottom organisms were absent. In the range of roach juveniles, bottom organisms and mollusks prevailed. The food similarity indices for juvenile fish in the Curonian Lagoon are quite high, which may indicate a tension in food relations between juveniles and (or) partial or complete overlap of their food niches. The weakening of food competition is ensured by the divergence of daily dietary peaks. Three-spined and nine-spined sticklebacks as well as a sabrefish and sticklebacks have the closest food spectrum. On the contrary, sabrefish and bream have a different food spectrum. The peculiarity of feeding of pikeperch juveniles in 2016 was the lack of transition to predatory nutrition.

Data on blood and blood-forming organs of species of the cyprinidae and perch family species living in the rivers of the Yaroslavsky State Nature Reserve were obtained. It was revealed that the hematocrit level in the studied species varied in the range of 23-42%, the total number of erythrocytes was 1.29-2.20 m / pkl, and the number of leukocytes was 65.9-141.2 thousand/ pkl. The relative number of peripheral blood leukocytes varied in the range: lymphocytes 87-90 %, segmented neutrophils - 3-7.5 %, stab neutrophils - 1-4%, monocytes and eosinophils - 1-3%. The relative number of lymphocytes in the organs increased in the series mesonephros, spleen, and liver. The number of hemocytoblasts, on the contrary, decreased. The relative number of myelocytes and metamyelocytes in mesonephros and spleen varied from 1 to 3%, promyelocytes - from 2 to 4.5%. Of all the species studied in the liver, myelocytes were found only in the bersh; no hemocytoblasts and promyelocytes were found. Regardless of the organ, the relative number of macrophages, plasmocytes and eosinophils varied from 0 to 3%, stab neutrophils from 3 to 8.5%. The number of segmented neutrophils in the mesonephros and spleen varied from 3 to 11%, in the liver this indicator was 1-3%. The range of obtained values for the studied indicators was comparable with the previously obtained data for the considered fish species living in relatively clean sections of the Rybinsk Reservoir and its tributaries. It was established that the trophic status of the species exerts the greatest influence on the hematocrit level, the total number of peripheral blood leukocytes, and the relative number of leukocytes in peripheral blood and mesonephros.

There are two main areas of pacific salmon fishing in the Magadan region: Shelikhova Gulf and Tauiskaya Bay. The main fishing species is pink salmon in the region. Its share of total salmon catch by odd-year returns reaches 85%. Data on the dynamics of escapement to the spawning grounds of pink salmon of the Shelikhova Gulf and Tauiskaya Bay are presented. The displacement of the level of spawning returns of pink salmon into the Shelihova Gulf with the simultaneous reduction of its returns to the Tauiskaya Bay is shown. Data on the dynamics of the fishing indicators of pink salmon for the two main fishing areas are provided. The Tauiskaya Bay as the main pink salmon fishery area loses its importance is shown. Graphical data on the escapement of producers pink salmon to the spawning grounds are presented and the optimal values of spawning escapements are estimated. Chum salmon is the second largest and most fishing species. Information on the dynamics of the number of returns, catch and escapement to the spawning grounds of chum salmon is given. The indicators of escapement to the spawning areas and their compliance with the optimal passes of salmon producers are analyzed. The issues of the dynamics of returns number, catch and the escapement to the spawning grounds of coho salmon producers are considered. The level of the escapement to the spawning areas is shown and the ratio of actual to optimal values of passes is estimated. The role of coho salmon as an object of industrial fishing and amateur fishing is shown. The extent of fishing press on individual groups of salmon populations is discussed. It is concluded that it is necessary to remove the main salmon fishery from the Tauiskaya Bay to the Shelikhova Gulf.

Based on a model describing changes in the number and biomass of fish generations during the life cycle with natural mortality depending on the age of fish, quantitative characteristics of the conditional population of the Caspian Beluga, which is formed with an annual replenishment of 1.0 million copies, are calculated. young of the year. Calculations of the number, biomass, annual production and P/B - coefficients were also performed for conditional populations of Volga-Caspian fish included in the Beluga food spectrum. Studies have shown that the number and biomass of generations formed from fingerlings and conditional populations of the studied species depends on the growth rate of their young in the first year of life, as well as on the size and body weight at which 50% of the individuals of the generations Mature. Among the studied fish species, Beluga is the most productive. The lowest generation productivity and high natural mortality are observed in populations of short-cycle, early-maturing fish-Caspian keels, gobies, aterines, etc. The number of generations of the studied species changes during their life according to decreasing curves, the biomass-according to single-vertex parabolic curves with a maximum occurring at the age of 50% of puberty. The highest annual output and P/B coefficients are observed in individuals of younger age. Individual and group feed ratios of fish increase with age. Using a physiological method, individual and population nutritional needs of a conditional Beluga population with a 20% catch of spawning stock were calculated. Based on the obtained data on the absolute age structure of the conditional Beluga population, individual annual food needs and products of the consumed feed base, the volumes of artificial and natural reproduction are calculated, which ensure the formation of reserves and obtaining catches in accordance with its annual food needs and the products of the used feed base.

Certification according to the standards of the Marine Stewardship Council (MSC) is highly demanded in the world market of seafood products. In Russia, a number of fisheries already have MSC certificates, but still there is a significant potential for certification of other fisheries. This requires analysis of the experience of companies that have successfully obtained the certification. Special attention should be paid to smallscale fisheries, whose financial opportunities to participate in certification programs, unlike large fisheries, are seriously limited. In the present work, process of ecological certification of fishery is considered on an example of the gillnet fishery of European perch Perca fluviatilis in the Irikla Reservoir, located in the middle course of the river Ural in the Orenburg Province. The catch volume of perch is 200-250 metric tons during the recent years. Fishing companies that fish in this reservoir have been working on MSC certification for over ten years. Process of certification has shown that the fishery meets the necessary standards, but even after the certification completed in 2016, there is a need for certain activities to support certification. These are in-depth analysis of the recreational fisheries, development of research plans in cooperation with scientific fishery institutes, specifically aimed at informing the certification process, independent analysis of the fisheries man

The technogenic transformation of the ecosystem of the southeast part of Luga Bay water area (the second bay of the Baltic Sea) where Ust-Luga commercial seaport situated was determined by longstanding dredging, dumping and other types of anthropogenic impact. The development of phytoplankton as the main primary production former and the base of food reserve for aquatic biological resources was investigated during the monitoring of aquatic biological resources of the Luga Bay which was held due to the seaport construction. The investigation of phytoplankton content and development took part in the main seasons of the ice-free period of 2005-2018 in the water areas of dredging, damping, and adjacent areas. The maximum values of the phytoplankton abundance and biomass were detected in spring. The main part of biomass was formed by diatoms and dinoflagellates. The summer biomass mainly was lower than in spring and the proportion of cyanoprokaryotes (in some years also cryptophytes and green) increased. In autumn the biomass decreasing was continued, cyanoprokaryotes and cryptomonads dominated. The quantitative indicators of phytoplankton development were varied from year to year in all seasons of 2005-2018 but they kept in frames of values which previously observed for the water area of the Luga Bay. The influence of the Gulf of Finland water warming on phytoplankton development was not traced. The certain differences between the quantitative development and composition of the dominant phytoplankton complex on the water areas of dredging, damping, and adjacent areas weren’t observed. The average phytoplankton biomass for the ice-free period in the most part of years corresponds to the mesotrophic state of the Luga Bay water area. There was not a significant impact of dredging and dumping on the phytoplankton of the Luga Bay which indicates the stable state of its ecosystem primary producer and the preservation of the productional resource of the fish food base.

Malnutrition problems are acute in all countries and are common to all socio-economic groups. Improper nutrition is the cause of cardiovascular diseases, diabetes, gout, osteoporosis, obesity and other non-infectious (nutritional) diseases. Aquatic bioresources, especially underutilized fishing objects, are sources of a number of irreplaceable nutrients, which makes them useful for creating functional and specialized foods. So stuffing on the basis of muscle tissue makrouruz and mackerel is a promising raw material for the production of pasty food products. Based on regulatory documents and methodological recommendations in the field of specialized, functional and therapeutic nutrition, a scientifically-based selection of functional food ingredients was carried out to create a pasty food product - pate. As a result of the simulation, seven formulations of pates were developed on the basis of the minced meat of makruirs and scad. Developed pates for a number of indicators correspond to the products recommended as therapeutic nutrition in hospitals.

The results of complex research carried out in the East Siberian Sea on board of RV “Professor Levanidov” in September 2019 are presented. The formation of positive air temperature anomalies over the sea, the expansion of the zone of river flow influence in the central and southeastern parts of the shelf, and an abnormal decrease in sea ice cover were noted. Arctic water masses and the waters of the East Siberian Sea were dominant on the shelf. At depths of more than 180 m, waters of Atlantic origin were well traced by salinity more than 34.5%o, positive temperature and silicon content less than <10 pM. Photosynthesis processes were limited by nitrogen, whose concentrations in the photic layer were reduced to analytical zero. Summer phase of phyto- and zooplankton development was observed in most of the sea. The main contribution to the total biomass of mesoplankton was made by copepods and chaetognaths. Plankton biomass on the inner shelf was twice as high as on the outer shelf. The average benthic biomass in trawl catches was 15 kg per mile, of which up to 74% was echinoderms and 9% crustaceans.17 fish species from 6 families were registered in trawl catches. The dominant species was the polar cod Boreogadus saida found in small numbers almost everywhere at depths 33 to 250 m with bottom temperatures from -1.7 to 0.47 °C, kept sparse, without forming dense aggregations. Maximum concentrations were observed in the southeastern part of the study area. High intensity of fish feeding was noted. Diets of polar cod and snailfishes (Liraridae) consisted mostly of hyperiids, gammarids, and copepods. The diet of capelin Mallotus villosus was dominated by copepods. Polychaetes and gammarids formed the bulk of the diet of sculpins (Cottidae). Microplastics are found in small quantities in the southeastern and central part of the sea only. Tissue samples were collected for population-genetic analysis, DNA-barcoding studies, and analysis of aquaDNA.

In September 2019, the R/V “Professor Levanidov” carried out comprehensive studies in the Laptev Sea from 140 ° to 110 ° E at depth range of 60-950 m. High positive anomalies of air and surface water temperatures were noted up to + 2 + 3 °C and +1.5 °C respectively with an abnormally low sea ice cover. Cold Arctic and desalinated waters of the river flow dominated in the upper 200 m layer. Atlantic waters were traced in the layer from 180-3ОО m to the bottom, and their core - at a maximum temperature of + 1.6 + 1.92 °C at 240-280 m. By the time of the survey, the active vegetation of phytoplankton had finished. Oxygen saturation in the almost the entire surface layer was below 100 %. Primary production was limited by mineral nitrogen concentration. Low concentrations of phosphates, nitrates and silicates in the intermediate waters indicated the penetration of Atlantic waters. The average biomass of plankton on the shelf was 239,8 mg/m³, on the slope - 374,2 mg/m³. Copepods and chaetognaths with considerable contribution of hyperiids and euphausiids dominated in plankton by weight. The bulk of zooplankton was large organisms, while small and medium fractions were 22 and 10%. Brittle star, starfish, and shrimp dominated in trawl benthos. 25 demersal fish species of 14 families were found in bottom trawl catches. Zoarcidae, Liparidae and Gadidae were the most diverse. Polar cod was recorded along the entire route with highest concentrations in Atlantic waters at depths of 217-460 m. Copepods dominated in the diet of Polar cod juveniles, while that of adults was supplemented by large pelagic crustaceans and fish with high level of cannibalism. Greenland halibut was found along the entire continental slope at 270-750 m while the largest catches were in its central and western parts. The increase of halibut number and occurrence was due to the wide distribution of Atlantic waters on the slope. The main component of its diet was Polar cod.