Information on the stocks state, timing and dynamics of spawning migration, and biological parameters of pink salmon on the continental coast of the Okhotsk Sea is presented for entire period of observations. Factors influencing the stocks, body size, and fecundity are considered. Geographical and temporal structure of the species in the region is revised.

Long-term data on downstream migration, qualitative and quantitative characteristics and feeding of juvenile chum salmon are generalized for the continental coast of the Okhotsk Sea. The downstream migration begins in conditions of certain heating of river waters; its dynamics depends on the rate of water flow and other environmental factors. The juveniles migrate from rivers to the coastal waters both in the daytime and at night. Their qualitative characteristics change in correspondence with escapement of either summer or autumn races of chum salmon progeny from the spawning grounds. The juveniles stay in the coastal waters until September. Their food spectrum is determined by the inhabited biotope.

Spatial distribution and abundance of walleye pollock are considered for the northwestern Bering Sea in the summer-fall of 2020 on the data of echo-integration trawl-acoustic survey. The pollock aggregated mostly in the shelf areas with positive or close to zero water temperature, with the higher concentration in the high-gradient zones. The densest aggregations (> 300 . 103  pcs./nmi²) were found in the eastern part of the Gulf of Anadyr and at the line between the economic zones of Russia and USA. Characteristic acoustic images and daily distribution of walleye pollock on the survey transects are presented. Spatial and bathymetric differentiation of certain size groups of pollock are revealed. More than 83 % of the fish were counted in the areas with bottom depth of 50–150 m. Immature walleye pollock with the size of 21–37 cm accumulated mainly in the areas with bottom depth of 75–125 m. Interannual dynamics of the size composition and abundance of walleye pollock in the northwestern Bering Sea is considered on the data of trawl-acoustic surveys in 2013–2020. The fluctuations of abundance and distribution are compared with changes of thermal conditions. Significant dependence of the pollock abundance on the mean anomaly of bottom temperature is confirmed (correlation coefficient +0.69): the species biomass was noticeably higher and its distribution was wider in the years with favorable (relatively warm) thermal regime than in cold periods.

A quasi-cyclicity associated with variability of environmental conditions is detected for the regression residuals of the stock-recruitment model for chum salmon Oncorhynchus keta in the Okhotsk district, described by Ricker’s equation. The main factors influenced on the chum progeny abundance were the number of spawners and the amount of precipitation in the spawning grounds area in certain months. A mathematical model has been developed that simulates satisfactorily the dynamics of progeny, which can be used for forecasting. Role of the freshwater and marine periods of chum salmon life in formation of the year-classes strength is discussed.

By monitoring of fish in the Alekseev Bay of Popov Island with the long-time underwater video observation system, greater amberjack Seriola dumerili (Risso 1810) (Carangidae) was registered in the second time in Peter the Great Bay and several species were registered in the first time in the Alekseev Bay (Oplegnathus fasciatus, Pholis crassispina, Gymnogobius heptacanthus, Salangichthys microdon, and Liparis agassizii). The list of fish species for the Alekseev Bay is widened to 60 species.

Taxonomy status of genus Cleisthenes was revised several times from the time of its description (Jordan and Starks, 1904) to nowadays. Some species of this genus were even assigned to genus Hippoglossoides. At present, the stumbling block in taxonomy of the genus is: whether the genus is represented by two species (pointhead flounder Cleisthenes herzensteini and pinewood flounder C. pinetorum) or only one. The problem cannot be easy solved because of many contradictions in previous studies. On the base of retrospective information on taxonomy of these/this species, statistical significance for divergence of some morphological indices is identified by the Kolmogorov-Smirnov criterion of homogeneity, that prevents reduction of diversity for the forms pinetorum and herzensteini to one species. The flounders of genus Cleisthenes dwelling the waters of the Sendai Bay (Miyagi and Fukushima prefectures of Japan) are obviously C. pinetorum, whereas the rest of this genus range is inhabited by C. herzensteini.

Chub mackerel became an important object of Russian fishery in the NorthWest Pacific since 2015. Annual catch of the species by Russian fleet reached 87,388 t in 2021. The data of trawl catches by Russian fishing vessels in the national waters in autumn of 2015–2021 are considered for possibility of CPUE standardization taking into account the factors of fishing gear and environments. Generalized additive models (GAM) were used as the method, the best model was chosen using the information criteria of Akaike and Schwarz. The selected model explains 63% of dispersion and includes such predictors as coordinates of catch, date of catch, vessel length, engine power, number of fishing vessels, and SST. Influence of these factors on CPUE is interpreted and discussed.

A method for assessing the degree of marine pollution (TPF_chem) is developed using a bioassay approach. The index TPF_bio is calculated as the average coordinate of the optima of response curves (along the TPF_chem gradient) known for the taxa of macrozoobenthos found at each station. The scale for correspondence between TPF_chem and TPF_bio is determined, separately for the fine-grained bottom sediments (with more than 10–12 % of particles < 0.05 mm) and for the sediments with lower portion of fine particles. Any list of species can be processed. Besides the assessing the level of chemical pollution, the method allows to correct results of chemical assessments and to restore dynamics of anthropogenic impact or to trace accumulation of pollutants at the seashore. However, reliable results of this method can be guaranteed for the coastal waters of Vladivostok only.

Structure and abundance of phytoplankton community in the Sportivnaya Harbour and Paris Bay in Vladivostok (western coast of the Japan Sea) was monitored from October 2019 to December 2021. In total, 130 and 144 phytoplankton taxa were identified in these two areas, respectively. The overall cell abundance ranged from 1.3 · 103  to 19 · 106 cells/L (on average 21 · 104  and 84.5 · 104  cells/L); the total phytoplankton biomass — from 3.0 mg/m³ to 38.5 g/m³ (on average 0.8 and 2.6 g/m³, respectively, by areas). The long-term observations were made for the first time in the Sportivnaya Harbour. The community composition was typical of eutrophic waters, with usual seasonal succession in the Paris Bay but frequent blooms in the Sportivnaya Harbour, when diatoms were replaced by flagellates and filamentous cyanobacteria. Such dynamics is presumably caused by anthropogenic eutrophication due to uncontrolled wastewater discharge.

Microelements (Pb, Cd, As, Hg, Fe, Cu, Mn, Cr, Ni) are investigated in the tissues of saffron cod Eleginus gracilis caught in the coastal waters of Sakhalin Island in 2020. The samples of weight about 1.0 g were taken from thawed fish, treated with concentrated nitric acid, and mineralized in a microwave oven; the mineralizates were dissolved in distilled water and quantitatively analyzed twice. The microelements distribution in the organs of fish was heterogeneous, but their concentration never exceeded the permissible sanitary and hygienic levels.

Survival of the larvae of marine parasitic nematode Anisakis simplex sensu lato (Rudolphi, 1809) in the fresh waters was monitored. In total, 37 live larvae of A. simplex s.l. were sampled from charr Salvelinus malma caught in the lower reaches of the Kamchatka River. The larvae were kept in the freshwater refreshed everyday, without food, their viability was examined daily at 9 a.m. All larvae were still alive in the 4^th day (100 %); 2.7 % were alive after 9 days in freshwater, but all of them were died after 10 days. Dependence of the number of dead larvae on the time of their exposition in the freshwater is well approximated by von Bertalanffy equation (R² = 0.996). Besides, viability of A. simplex s.l. larvae in the bodies of dead sockeye spawners was examined at the spawning grounds in Lake Azabachye: the larvae were alive in the body cavity of fish that died at least 3–5 days ago and remained alive at least 3 days more being placed in the freshwater. The larvae of marine nematode A. simplex s.l. are able to enter to the fresh waters with migratory fish. Following to our results, they can survive there for several days. So, measures for disinfecting against A. simplex s.l. are recommended for the freshwater fish caught in the water bodies connected with the marine environment.

The areas with prevalence of either production or decomposition of organic matter are localized in the estuaries of Uda and Usalgin Rivers (western coast of the Okhotsk Sea) on the data of chemical survey conducted in conditions of summer flood in July, 2016, interpreting patterns of non-conservative variations of inorganic phosphorus concentration (deflections of observed values from potential values determined by the river water mixing with the seawater). Sign of production-destruction balance changed along both surveyed estuaries: the organic matter decomposition prevailed in the internal estuaries but its production prevailed in the upper part of the external estuaries. Another common feature of both estuaries was active recycling: the larger portion of organics was produced with utilizing the phosphorus mineralized within the estuaries, but not the terrestrial phosphorus provided by the rivers ionic discharge. Extremely intensive recycling was observed in the Usalgin estuary that drained swampy lands.

Effectiveness of starter fodders is examined for the low-temperature rearing pools in the salmon fish hatchery Savushkina (Severo-Kurilsk). In May 2022, the experimental compound feed developed in TINRO was compared with the control fodder Aller Aqua (made in Denmark) when feeding of chum salmon fry. Both fodders complied with the veterinary and sanitary requirements of the Euro-Asian Economic Union in terms of quality and safety. The following fish breeding indices were determined for the experimental/control fodders after 47 days of testing: feeding ratio 0.670/0.467; mean daily gain 1.255/1.547 %; mean final weight 0.630/0.735 g; absolute weight growth 0.287/0.392 g; mortality (survival) 0.50 (99.50)/0.48 (99.52) %. Increasing of the water and minerals content and noticeable decreasing of the protein and fat content were detected in tissues of the control samples of fry by comparative biochemical analysis before and after the testing, whereas the content of protein and minerals had increased in tissues of the experimental samples. Thus, suitability and effectiveness of the experimental starter fodder for rearing of juvenile chum salmon in the low-temperature environment is proven by combination of several indices. To intensify the weight gain of juveniles, the experiments will be continued to adjust the composition of mixed feed for juvenile chum salmon in the cold-water conditions, with a principal restriction of the growth intensifiers (hormones) use. The starter compound feed developed in TINRO is recommended for using in rearing of chum salmon fry.

Sulfated glycosaminoglycans (GAGs) or chondroitin sulfates were obtained from the cartilage tissue of skate (indefinite species) and sturgeon (kaluga) under the processes of hydrothermal treatment of raw materials at 50 ^оC, then hydrolysis with proteolytic enzyme in 4 hours under temperature 45 ^оC (hydromodulus 1 : 1), then sequential precipitation of GAGs in 2–3 volumes of 96^о  ethyl alcohol and salting out with 2 % sodium chloride solution. The content of hexosamines and sulfated GAGs was determined in the extracted samples. GAGs of both skate and sturgeon have a high content of sulfated forms, comparable to commercial preparations, that opens up prospects for development of technology for production of monocomponent biologically active additives of chondroprotective action from the wastes of skates and sturgeons processing.

Nutritional and biological value and the dietary lipid indices are determined for 2 recipes of pate canned food from japanese sardine Sardinops melanostictus (sardine-iwashi). The first recipe uses the fish and vegetable raw materials, but the second one includes additionally vegetable oil used for sautéing of the vegetables. The content of proteins in both products was 13.7–15.5 %, fat content — 14.3–17.4 %, carbohydrates — 4.6–4.8 %. The proteins were completed and balanced in terms of amino acid composition. The lipids were represented mainly by triacylglycerides, the portion of phospholipids was 6.0–6.4 %. Among fatty acids of the lipids, the most numerous group was PUFAs (38.8 % of the total amount of fatty acids for the 1^st recipe, 41.3 % — for the 2^nd recipe). The PUFAs amount in 100 g of canned food was 5.86 and 7.05 g, respectively. The content of omega-3 and omega-6 PUFA was 25.2 % and 9.9 % of the total number of fatty acids for the 1^st recipe and 18.6 % and 20.5 % for the 2^nd recipe. Among PUFAs, eicosapentaenoic acid (20:5 n-3) dominated in the pate of the 1^st recipe (14.2 %) but linoleic acid (18:2 n-6) dominated for the 2^nd one (19.6 %). The sum of eicosapentaenoic and docosahexaenoic acids was 19.0 % of total fatty acids or 3.14 g/100 g of the pate for the 1^st recipe but 14.1 % or 2.40 g/100 g for the 2^nd recipe. The dietary indices (or health lipid indices) were determined as the ratio of certain saturated and unsaturated fatty acids in the product. The indices of atherogenic- ity and thrombogenicity were 0.59 and 0.24 for the 1^st recipe and 0.41 and 0.24 for the 2^nd recipe, respectively. The hypocholesterolemic index was evaluated as 2.26 and 3.49 for the 1^st and 2^nd recipes, respectively. Low values of atherogenicity and thrombogenicity and high value of hypocholesterolemic index provide positive effect of the lipid profile on cholesterol metabolism and rate of thrombosis in the human blood vessels.

New attempt to answer the questions: 1) what aquatic biological resources are possessed in the Russian Far-Eastern Seas and North Pacific and what is their quantity? 2) which of them and how many are caught annually? 3) are these resources managed rationally in Russia? 4) and what is the reason for current situation and can it be improved? Based on the data of trawl surveys, a GIS is created with maps of the biological resources distribution, separately for actually harvested, potentially commercial, and non-commercial ones. The biomass, potential yield and its cost are calculated for the Chukchi, Bering, Okhotsk, and Japan Seas and North-West Pacific. These water bodies are ranked by their value for commercial fisheries. The obtained estimates are compared with the data on annual catch, export, import, and consumption of fish products in Russia. Possibility of larger landing is concluded for each water body, in terms of the harvested species biomass. The harvest from the Okhotsk Sea alone can reach more than 5.2 million tons that exceeds the level of «strategic ceiling» for the entire Russian fishery proposed in «Strategy for development of the fisheries complex of Russian Federation for the period to 2030». For the whole water area under consideration, this level can be exceeded by 3.5–4.7 times, or even by 5.6 times if the potentially commercial species will be exploited. Dynamics of domestic catch, trade and consumption of the biological resources are analyzed. The conclusion is that socioeconomic conditions rather than the state of biological resources are the reason that Russia still does not harvest so much. Some measures are proposed to improve the management of the Russian fishery industry. The obtained results cah alsobe used for maintenance rational use of the biological resources, food security, and nature protection, including evaluation of cost for biological resources in certain water bodies and assessment of damage caused to the nature and biological resources by pollution, construction, oil and gas production, or technogenic accidents.

Dynamics of catch, import, export, and consumption of fish products are analyzed for 1970–2020 on the data of Russian Federal State Statistics Service. Despite steady increasing of the annual catch since 2004, the consumption still does not reach neither the target level claimed by the Food Security Doctrine, nor the norm established by Federal Service for supervision of the consumer rights protection and human welfare, nor even its volume before 1990. The import of fish products (12–47 % of the domestic catch, by years) does not save the situation, because of exponential increase of the export with the catch increasing (from 31 % of the catch in 2000 to 61 % in 2020). This effect made a statistically significant negative impact on the domestic consumption since 2013, when the export exceeded US$ 3.5 billion per year. Now the more fish products are caught, the more they are sold abroad, mainly to unfriendly countries participated in the sanction war against Russia, with detriment to national food security. It is proposed to change the rules of foreign trade: to allow the fish products export abroad only after fulfillment of the norms for their delivery to the domestic market.

The biomass of pacific cod (Gadus macrocephalus) in the North Kuril fishing zone is estimated using a multifactorial approach, with evaluation of uncertainty. For this purpose, the density of fish over entire zone is restored using the data on density obtained in 2022 compared with the data of previous surveys and fishery data obtained in 2021 and earlier, converted to the same scale, with application of the machine learning method, as the random forest in the multiple imputation by chained equations procedure (MICE). The coefficient of the restored data determination with out-of-bag (test set) data was > 0.8 with the data of scientific survey in 2021 and > 0.5 with the data of Danish seine observations. The cod density variance in MICE data was in 82 % lower than in the data of the scientific survey; therefore the biomass estimation with MICE data has lower uncertainty than that one calculated just from the mean density in survey. The study showed insignificant difference of the cod biomass in 2021 and 2022. Spatial segregation is revealed for fishing gears used for the pacific cod fishery. There is proposed to extend the list of fishing gears and to expand the study area for reducing possible bias in the biomass estimation due to large area of extrapolation.

Two modifications of unmanned aerial vehicle (UAV) survey on spawners of pacific salmons are examined for certain rivers in Sakhalin and Khabarovsk Regions. The route survey along the rivers was tested to evaluate its applicability for the salmons counting in prespawning and spawning aggregations. Poor suitability of such approach was found for some of surveyed rivers. For these rivers, an alternative approach was proposed, as a localized UAV survey with shooting video over contrast background, like tower videocounts widely used in North America. This kind of survey can be easy adopted for many rivers of southern Sakhalin due to their spatial proximity, transport accessibility, and rather dense population in this area. Detailed technical recommendations for the UAV counting on observation transects are provided and limitations for this approach are shown. The route UAV survey allows to make inventory of the salmon spawning grounds and to evaluate the spawning efficiency, whereas the local UAV survey solves a narrower task for operative fishery regulation as counting the spawners escapement to rivers.