Algal flora of the northwestern part of the Bering Sea is studied insufficiently. The data for the present study was received from herbarium collection of 1969 from the Anadyr Gulf and collection of 1999 from the northwestern part of the Bering Sea, kept in the herbarium of the VNIRO. There were identified 76 species of algae: 18 - Phaeophyceae, 16 - Chlorophyta, 42 - Rhodophyta. Among them twenty-two new species were identified for this region: Sphaerotrichia divaricata, Scytosiphon lomentaria, Chaetopteris plumosa, Derbesia marina, Chlorochytrium schmitzii, Acrosiphonia saxatilis, Ulvella ramosa, Ulvella geniculata, Erythrocladia irregularis, Lithophyllum dispar, Lithothamnion sonderi, Clathromorphum nereostratum, Leptophytum leave, Phymatolithon lenormandii, Phymatolithon lamii, Meiodiscus concrescens, Neodilsea yendoana, Gloiopeltis furcata, Turnerella mertensiana, Fimbrifolium spinulosum, Peyssonnelia pacifica, Congregatocarpus kurilensis and Odonthalia ochotensis . The total amount of algae of the coastal zone of the northwestern of the Bering Sea includes 128 species: 32 Phaeophyceae, 31 Chlorophyta and 65 Rhodophyta.

In 2017, research work continued on the study of the resources of commercial crabs in the 12-mile coastal Pacific zone of islands Shumshu and Paramushiro and the Okhotsk Sea part of the islands. A map of bottom temperatures was constructed on the basis of data obtained from TERMOCHRON sensors. The results obtained give an idea of the magnitude of the bottom temperature in the study area. In the area of the northern Kurile Islands, there are aggregations of king crab (Paralithodes camtschaticus), horsehair crab (Erimacrus isenbeckii) and bairdi snow crab (Chionoecetes bairdi), the distribution of which is largely due to the temperature of the bottom water in the area of the islands. The limits of the “comfortable” temperature for the crabs studied were determined. A significant change in water temperature with the typhoon approach, which affects the formation of crab aggregations, is shown. It has been proposed that large aggregations of the Kamchatka crab are formed in the temperature “lenses” of water at an average temperature of 3.7 C. The data on all the studied crabs are presented: size structure, maturity, intermolt stage, analysis of their relationships with other populations. Full information is given on the distribution of three species of crabs in the northern Kuril Islands based on the data obtained in 2015 and 2017. The maps of spatial distribution were constructed and indices of commercial stock for crabs were calculated using the algorithms of the integrated GIS “KartMaster” complex and the “Bioresource” database. Proposed fishing areas for crabs of the islands of Shumshu and Paramushir in coastal fishing mode.

The absolute, relative individual, and relative population fecundity (average number of eggs per ovigerous female) in ovigerous females of the blue king crab ( Paralithodes platypus ) from the northern part of the Sea of Okhotsk were analyzed. The absolute fecundity varied from 15 000 to 181 900 eggs per female and increased with the body size in all areas under study. The maximum upper values of absolute fecundity were registered near the bank and Iony Island, as well as in the Shelikhov Gulf. The minimum upper values were recorded near Cape Khanyangda. Equations describing the dependence “fecundity - carapace width” were provided for every investigated area. For same-sized females, the absolute fecundity was higher in the Shelikhov Gulf and lower near Cape Khanyangda. The relative individual fecundity varied from 56 to 205 eggs per 1 g of specimen body weight. The mean values of relative fecundity within the studied areas differed insignificantly. The relative population fecundity decreased from east to west along the coast of the Sea of Okhotsk, from the bar of the Gulf Shelikhov to Cape Khanyangda. Its maximum and minimum values were 87 300 and 39 500 eggs, respectively. The relative population fecundity of P. platypus from the bank of Iony Island was not subject to clinal variability due to the specific hydrological conditions of the area. The mean reproductive effort varied slightly between the studied areas and equaled 9.0-10.8%. The average width and length of purple and eyed eggs were 1.05 and 1.21 mm and 1.21 and 1.43 mm, respectively.

Arabesque greenling Pleurogrammus azonus is an important commercial species in the waters of Russia and Japan. In the sexual dimorphism of the Arabesque greenling, specific features and age differences are revealed in terms of somatic and generative growth, fat accumulation and nutrition. During the first two years (juvenile stage), the specific speed of linear and weighty growth of females is ahead of that in males. The “inertia” of the accumulated changes allows females to remain larger than males, despite the fact that maturing and mature males have rates of somatic growth already higher than females. Thus, the milestones of ontogenesis is determined not only by the speed of the processes, but also by the accumulated changes. Analysis of sex differences in somatic and generative growth leads to the construction of the same scheme of stages of ontogenesis, which was revealed in the analysis of the general sample without division into males and females. The durability of the stages of the stages of maturity and aging is specified, which was previously determined heuristically. The stage of aging is characterized by equalization of differences between males and females. The shorter life expectancy and earlier maturation of males is determined by their higher metabolism at the maturity stage.

Length-weight composition, sex ratio and age structure of three most abundant species of gobies in by-catch of passive fishing gear in the Kerch Strait: round goby, monkey goby, tubenose goby, are described. The share of these species among total number of the captured gobies varied from 13.9 (monkey goby) to 59.6% (round goby). Spatial distribution of the studied gobies in this region depends mainly on distribution of bottom habitats, which these goby species prefer. Standard length of the round goby in by-catches of passive gear in the Kerch Strait varied - between 3.5 and 16.4 cm, monkey goby’s length - from 5.5 to 15.1 cm, and tubenose goby’s from 3.7 to 8.1 cm. During the year, the mean length of round goby in passive gear catches decreased. The amount of round goby females in by-catches of passive gear was larger than that of males. Among the captured specimens of monkey goby, males prevailed during the entire research period. The amount of males and females of the tubenose goby was close to equal. In catches of passive gears in the Kerch Strait all age groups of the investigated goby species occurred but the main part of all the studied goby species were specimens at the age of 2-3 years. The obtained data allow to suggest that the populations of the studied goby species are now in a stable condition.

The structure of the previtellogenic oocyte pool was studied in rainbow trout at the age of 10 and 20 months. It was shown that percentage of oocytes of different size groups in the females of the same age differs significantly and does not depend on length and mass of the fishes. The meiotic oocytes entered previtellogenesis in multiple cycles that was followed by the structural change of the whole their pool. The moments of transition from the fund of meiotic oocytes to the fund of previtellogenic oocytes, as well as from individual size groups of previtellogenic oocytes into subsequent size groups are not determined by the size of the fish, but are related to the dominance phase of the oocytes of one or another size group. With these multiple “waves” in the structure of the oocyte stock, a general increase in their number is associated. As a result the percentage of oocytes in different size groups changed. At the age of 10-20 months the number of previtellogenic oocytes in rainbow trout females increased 9 times, at average from 25,8 to 239,5 thousand.

The article provides information about the features of nutrition of sterlet on different hydrological regime areas of the Oka river. The description of feed composition for the upper, middle and lower reaches of the river is given. The differences of the sterlet feeding spectrum on the river sections depending on the nature of the bottom substrates are shown. Characterized by major and minor groups of food objects in the diet of this species of sturgeon. The predominance of bivalves in the upper course of the Oka in the composition of the food clump, on the average - Brooks, and in the lower - larvae of chironomids was established. Examines the variability of the composition of the food of sterlet in the upper reaches of the river with increasing fish size from 20 to 50 cm during the growth of fish in the diet of sterlet Oka greater importance is bivalves. The intensity of sterlet feeding was calculated depending on the habitats and taking into account the differences in size groups. It is established that at present (2017) in the upper course of the Oka, the degree of feeding of sterlet due to its high number, significantly decreased compared to the previous period of research (2002).

Because of own and literature data shows some features of the biology and fisheries of the ordinary pike Esox lucius in the coastal waters of the Terek-Caspian fishery subarea. Features of formation of stocks of this field object in the conditions of influence of climatic and anthropogenic factors are shown. It is revealed that the reduction of spawning area in the last decade as a result of the Caspian sea level decrease, as well as a high proportion of unaccounted and poaching are the leading factors affecting negatively the state of pike stocks in the sub-district. The number of young pike in the surveyed area with fluctuations over the years has a General tendency to decline. As a result, during the period from 1997 to 2019, the commercial stocks of pike in the Tersko-Caspian fisheries sub-region decreased from 3.8 to 1.1 thousand tons, i. e. almost3.5 times. Under the influence of intensive fishing, there are changes in the structure of pike populations. During the period from 2013 to 2017, the average age of pike decreased from 4.2 to 3.8 years, the average length from 57.8 to 47.7 cm, and weight - from 2.16 to 1.25 kg. The consequence of the reduction of pike stocks in the area under consideration is likely to reduce its role in the regulation of small freshwater fish. For example, the commercial reserves of Rudd on the Dagestan coast of the sea from 2007 to 2018 increased from 0.51 to 1.24 thousand tons, and carp for the same period - 1.3 to 1.83 thousand tons. Recommendations on conservation and restoration of pike stocks in the region are given.

The study of the immunological parameters of juvenile catfish Silurus glanis, who had ichthyophthyriosis. In the spring, 2 groups of yearlings of 100 sick individuals were seated in different nursery ponds. Before planting, one group was kept for an hour in a bath with a healing solution: 60 g of sodium chloride + 60 mg of furazolidone + 100 mg / l of methylene blue for 20 liters of water. No other group was treated. In the autumn, after fishing for ponds, catfish from both groups of signs of disease were not detected. Some indices of humoral and cellular immunity were studied in fish from each pond. The group of catfish, which was kept in the treatment solution, had higher indicators of the bacteriostatic activity of the blood serum and the proportion of mature segmented neutrophils in the leukogram; the proportion of immunodeficient individuals and the percentage of blast forms of myeloid cells (myelocytes) are lower. There were no differences in the phagocytic activity of neutrophils between fish from different ponds. The data obtained indicate a positive effect of applying a therapeutic solution to restore the functional state of humoral immunity.

We studied somatotropes and adrenocorticotropes of the pituitary glands of male northern fur seals in postnatal ontogenesis. Special coloring methods were used (trichrome ShIK, tetrakhrom ShIK) and electron microscopic examination methods. The area of the nuclei and the area of the cells was measured, and the nuclear-cytoplasmic ratio was determined. Histochemical and electron microscopic features of somatotropes and adrenocorticotropes have been established, on the basis of which these two types of endocrinocytes of the adenohypophysis can be accurately determined. Somatotropes are intensively stained with orange G and contain large secretory granules, the size of which varies from 400 to 450 nm. The number of secretory granules and the degree of development of organelles characterize the level of cell differentiation and their functional activity. Adrenocorticotropes have a small size and in usual preparations in the cytoplasm of these cells no granularity is detected. In the electron microscope, small secretory granules are detected in a small amount, the size of which is 140-160 nm. Secretory granules evenly distributed throughout the cytoplasm. Changes in the cytokaryometric, histochemical, and electron-microscopic parameters of somatotropes and adrenocorticotropes in male northern fur seals in postnatal ontogenesis were studied. The maximum secretory activity of the endocrinocytes of the pituitary glands was found in males of northern fur seals at the age of 8-10 years.

Microscopic study of skin dark pigmentation in Acipenseridae, Salmonidae, Clupeidae, Percidae, Petromyzontiformes, Batomorphi and Selachii was conducted. In skin of all species dark pigmentation was defined presence of dark pigment-containing cells - melanophores which have different shape. Melanin inclusions that were not organized into melanophores were detected in early stages of ontogenesis in sturgeon.

According to long-term data, the structure of the catch and the state of fishing of the main species of aquatic biological resources in the Russian waters of the Bering Sea are analyzed. Fishery covers 33 species and groups of species of aquatic biological resources, among which 24 units are fish and 9 - invertebrates. The largest volume of projected total catch is marine fish, followed by potential catches of shellfish, algae, shrimps, crabs (combined group of crabs and craboids) and sea urchins in descending order. Real catches differ from forecast estimates: actually marine fish, Pacific salmon and shellfish also predominate in the total catch, but the fourth place in catches are crabs, shrimps are produced in significantly smaller volumes, sea urchins and algae are not caught industrially. The greatest development of the allocated resource was noted for Pacific salmon (98.0%), crabs (81.0%) and marine fish (76.0%), the smallest - for shellfish (14.7%) and shrimps (7.6%), which in general for the period 2000-2015 was reflected in the total underutilization of aquatic biological resources in the Bering Sea in the amount of 3591 thousand tons (26.9%). The forecast and actual figures of the total catch of individual groups and species of fish and invertebrates, which are extracted in the mode of total allowable catch (TAC) and recommended catch (RC), are analyzed. With the exception of salmonids, the species for which the TAC is established are characterized by the most development. Analytical materials on the use of biological resources of the Bering Sea make it possible to judge the existing potential of the raw material base, the effectiveness of fishery, the development of TAC and RC by domestic fishery in the modern period.

All size and age groups of nelma, least cisco, arctic cisco and muksun inhabit the estuarial area of the Lena River delta. Here they grow, mature and form their spawning stocks. Species differentiation is not observed on the feeding areas and fishery for any one species leads to the fact that other species are also caught in the nets, which results in the damaged structure of populations as a considerable amount of fish in first maturity is withdrawn. The research has shown that catching of nelma, arctic cisco, least cisco and muksun in the estuarial area of the Lena River delta with 55-60 mm mesh gillnets exceeds the permissible for fishing by- catch rates established by the Fishing Regulations for East-Siberian Fishery Basin. To save the stocks of nelma, arctic cisco, muksun and least cisco in the Lena River basin, it is necessary to utterly forbid fishing in the estuarial area of the Lena River delta and to move it to the river’s channel, which will allow to increase arctic cisco spawning stock in the nearest future and ensure the increase of muksun population in the long term (during two-three decades).

The oxygen consumption and the excretion of ammonium of adult white-legged shrimp Penaeus vannamei were studied at a water temperature of 27-28 C and salinity of 17-18‰. Ammonium excretion was studied on 18 shrimps, each of which was kept for 3 days, oxygen consumption was studied on 20 individuals for 2 hours each. It was found that shrimps starving during the day emit on average 0.150±0.062 g of ammonium nitrogen per 1 kg of live weight. When shrimps fed at a rate of 1.3% of body weight per day, the excretion of ammonium increased to 0.411±0.090 g/kg on the first day and 0.412±0.108 g/kg in the second. The result of an experiment to determine oxygen needs showed that shrimp consumes 383±71 mg of oxygen per 1 kg of live weight per hour. These indicators can be used in the design of closed water recirculation systems.

The technology of keeping and preparing for spawning of sturgeon producers in installations with a closed water supply provides for a relatively short (10-14 days) period of temperature reduction amid feeding cessation and subsequent wintering before spawning. This approach does not take into account the specificity of the nutritional needs of producers, due to the seasonal characteristics of their metabolism, including generative exchange. In experimental work carried out in aquarium conditions and in sturgeon farming of the industrial type, confirmation was obtained of the advisability of supplementing the technology of keeping sturgeon producers in the RAS, with a new stage - prewinter feeding of females. Its essence is the replacement of the traditionally used short period of reducing the water temperature to wintering values, a longer period of “autumn feeding” with a decrease in water temperature for 30-35 days while maintaining feeding. At 54 females of the Aksai bester and 49 females of the Siberian sturgeon, it was shown that pre-winter feeding of females (compared to starving fish) helps to improve the maturation of oocytes, as evidenced by an increase in their diameter and a more effective decrease in their polarization ratio (1.5-3 times). Feeding not only has a positive effect on the quality of preparation of females for spawning, but also makes it possible to ensure the production of more eggs. At the same time, the fertilization of eggs obtained from females fed increases by 10-17%, the development of embryos by 10-20%. The results of experiments under production conditions, which demonstrated an increase in the production of caviar (by more than 35%) in Siberian sturgeon females that fed in the pre-winter period, convincingly confirmed the feasibility of feeding them in a period of decreasing temperature. It was also shown that there were no significant differences in the period of the “autumn feeding” in the effect on females of high-energy feeds and the proposed specialized feeds with a reduced content of protein and lipids.

The results of the collection, analysis and systematization of modern equipment used in the flowing seawater systems for measuring the parameters of the aquatic environment when the RV is moving are presented. Examples are given and configurations and design features of the real equipment used on modern foreign RV are considered. A list of specific measuring parameters of seawater, their integration, and structural and methodological features in their choice and connection to the hydraulic system is given. A distributed system of organization of units and modules with a combined use of tanks for meters or groups of meters, is shown to be the most expedient in using for promising projects of FRV which allows change the system and configuration and composition of meters depending on the task. Research materials used in the works are related to the equipment of new FRV.

The material of the trap shooting performed in the deep-sea part of the Sea of Okhotsk in June-July 2018 is presented. The Zodiac research vessel surveyed the depths of 304-1150 m. Crab catch sorted by species. For a standard biological analysis, a random sample of crabs from several traps was taken, with large catches of crabs, they were additionally calculated by size-sex groups. For a short period of time, information on their biological status, distribution and instantaneous numbers has been collected over a vast area of habitat of deep-sea crabs.The data on the thermal conditions of crabs have been collected, the relationship between the filling of the limbs with muscle tissue in crabs and the protein content in the hemolymph is shown. We studied five deep-sea crabs - Lithodes aequispinus , L. couesi , Paralomis verrilli , P. multispina , Chionoecetes angulatus and one eribribny shelf species - C. opilio . It was revealed that, in research areas, the status of the commercial part in the populations of exploited crabs is stable and satisfactory.

In April 2019, hydrological, hydrochemical, planktonological and ichthyological studies were carried out in the waters of the central part of the Emperor Seamounts (northwestern Pacific). The species composition of fish was determined. The ratio of the main fish species on the Koko seamount was analyzed at different periods. New fish records in the study area were reported. The diet of main fish species was identified. The species composition of the cephalopods was determined. In recent years, in contrast to the 1960-1980s, the dominant species on Koko seamount was pencil cardinal Epigonus denticulatus , which density in 2019 was 3.7 t/km2. The most abundant commercial species in the past, pelagic armorhead Pseudopentaceros wheeleri and alfonsinos Beryx spp. currently did not form dense aggregations, their averaged density was 357 and 230 kg/km2 respectively. At present, the estimated commercial importance of the central part of the Emperor Seamounts is low.

Study of Atka mackerel Pleurogrammus monopterygius , which were conducted in four Far East fishing areas (01, 02.1, 02.2, 03) in April-May 2019, were presented. Distribution features of commercial Atka mackerel concentrations in different areas were shown; biological data of Atka mackerel and by-catch species were collected. The obtained data will be used to fish stock assessment and forecasting.

For the first time, a modern recording method for Baikal seal registration using unmanned aerial vehicles with an infrared and photo equipment was conducted in Lake Baikal. This method is significantly safer than the traditional registration on the ground and it is increases the area of possible multispectral surface scanning. The results will allow estimating the number of the recruits and total population of the Baikal seal in 2019 more accurately.