Cited data on anthropogenic pollution of the estuaries in south Primorye (northwestern coast of the Japan Sea) are briefly reviewed and analyzed. The estuaries are ranked by concentration of pollutants in the sewage disposed to the rivers and by integrated abiotic index calculated as the sum of toxicity in the bottom sediments and concentration of petrohydrocarbons in water and grounds. By these parameters, the oligohaline estuaries of big rivers as the Razdolnaya and Artemovka have the highest level of pollution, the mesohaline estuaries as the Tesnaya, Gladkaya, and Kievka have the intermediate rank of anthropogenic impact, and the polyhaline estuaries of small rivers as the Sukhodol, Shkotovka, Barabashevka, and Ryazanovka are low polluted. The estuarine ecosystems are generally well-adapted to high variability of environmental factors, and therefore are highly resistant to anthropogenic pollution. There is concluded that, despite of considerable pollution in some cases, dynamics of the estuaries dwellers abundance is determined mainly by natural factors, first of all by the volume of freshwater discharge, the estuarine ecosystems in Primorye function normally, and the state of their biological resources is sufficient. Thus, fishery, aquaculture, and recreations have at present good prospects in the estuaries and adjacent marine and river waters, in parallel with other economic activity, as hydraulic constructions, certainly under condition of all requirements of the nature protection legislation and with ecological monitoring. For these water bodies, technological and economic development can successively coexist with traditional nature management and wildlife preserving.

Unique database on zooplankton collected by 0.1 m² Juday planktonic net (mesh size 0.168 mm) in the Chukchi, Bering, Okhotsk, and Japan Seas and the North Pacific in 1984-2013 is presented. History of its creation, sources and volume of the data are described and the first operating experience and prospects of its using for applied and fundamental researches of marine biological resources are explained. Some new results based on this database are discussed. In particular, 5 tabular reference-books of species composition, occurrence and abundance of zooplankton for the main fishing grounds in the Russian part of this region were prepared and published in 2014-2015, where the information is summarized by species, stages of development, size fractions, biostatistical areas, water layers, light and dark time of day, four seasons, and quasi-decadal periods. Charts of spatio-temporal distribution of certain taxonomic and dimensional groups are drawn. Assumption is offered on negative dependence of zooplankton body size on water temperature, that needs additional verification. Vertical zooplankton migrations are considered and there is concluded that its biomass in the upper layer increases usually in the nighttime in the Okhotsk and Japan Seas but in the daytime in the Bering Sea and North Pacific, therefore attempts to recalculate the daytime biomass to the nighttime one using constant coefficients give opposite results for these pairs of regions. Prospects for developing of GIS and atlases of zooplankton for the North Pacific are discussed with examples of charts for the data generalized by abovementioned criteria, but this application is postponed until the best times because of funding reduction.

Spatial patterns of the pacific cod spawning grounds in the North-West Pacific are considered in the first time on the basis of its spawners occurrence and distribution of its larvae, fingerlings, and yearlings by samples collected in 179 surveys of Pacific Fish. Res. Center (TINRO) in 1975-2014 and cited data. The spawning grounds are located either at the shelf edge and upper continental slope for offshore forms of cod or on the shallows for its coastal form. The deep-water spawning grounds are related to the areas with shoreward currents that provide the transport of pelagic larvae and fry to the shallows favorable for their further development. They are located, by the regions: in the western Bering Sea - over underwater Shirshov Ridge, southward form Cape Navarin, in the Olyutorsky Bay, eastward from Karaginsky Island, at Commander Islands, in the Kronotsky Bay; at Kamchatka and Kuril Islands - off the northeastern coast of Kamchatka, at the southeastern Kamchatka between 50^о50′-52^о15′ N, in the Second Kuril Strait, at the Pacific side of Onekotan, Kunashir and possibly Shikotan Islands, in the Kunashir Strait, at the Okhotsk Sea side of Kunashir and Iturup Islands, at the western coast of Kamchatka between 51-56^о N; in the northern Okhotsk Sea - along the edge of the northern Okhotsk Sea shelf and possibly somewhere in the Shelikhov Bay; in the Japan Sea - in the De Langle Bay at the western coast of Sakhalin, in the Nevelskoy Bay, at Moneron Island, at northeastern coast of Primorye between 44^о27′-48^о10′ N, and at the southern Primorye coast. The shallow spawning grounds are poorly known, they are determined definitely in the Tauiskaya Guba Bay (northern Okhotsk Sea) only, but could be expected in other areas, too.

Data on oceanographic conditions and species composition of plankton, benthic and demersal fish and invertebrates are presented, obtained in the complex survey over the external shelf of the Laptev Sea in August-September 2015. The zooplankton abundance was low, with only local increases up to 400 mg/m³. Species diversity of fish and nekton invertebrates in the bottom trawl catches was low, too: 26 fish species and 2 species of cephalopods. Mean biomass of fish was estimated as 4.3 t/km² (in total 132^. 10³ t within the surveyed area of 30,500 km²). All fish species were distributed sparse. Arctic cod was the most abundant and occurred over the whole surveyed area, with large-sized fish dominating at the bottom and medium-sized (9-15 cm) fish - in the pelagic layer, other commercial species were greenland halibut and deepwater redfish caught on the continental slope. Bottom invertebrates in trawl catches were presented by 6 species of shrimp and 12 taxonomic groups of different rank, with predominance of starfish, brittle stars and sponges; gastropods were represented by 11 species, with Neptunea heros dominating by mass (42 %). Macrobenthos in samples of the bottom sampler was presented by 20 taxonomic groups, with predominance of polychaetes, bivalves and sipunculoids.

Stocks of demersal fishes on the depths of 20-200 m in the northwestern Bering Sea are considered, excluding walleye pollock Theragra chalcogramma , on the data of 10 bottom trawl surveys conducted in the summer-fall of 1985-2015. The mean total biomass of demersal fish in two parts of this area (Western Bering Sea zone and Chukchi zone) in this period was 747.78^. 10³ and 119.83^. 10³ t, with almost equal density distribution: 5757 and 5709 kg/km², respectively. The biomass had some redistributions in recent times: the assessments were 832.97^. 10³ and 69.88^. 10³ t in 2012, and 946.31^. 10³ and 141.40^. 10³ t in 2015, respectively. Pacific cod Gadus macrocephalus is usually the dominant species in the Western Bering Sea zone (up to 57 % of the total biomass in 2015) followed by subdominant species as alaska plaice Pleuronectes quadrituberculatus , flathead sole Hippoglossoides spp., alaska skate Bathyraja parmifera , and great sculpin Myoxocephalus polyacanthocephalus with portions of each species between 5-13 %. Generally, the ichthyocenosis of both zones was monodominant; the polydominant structure was observed in the Western Bering Sea zone only in 2001 and 2005, in conditions of abnormally low cod abundance. The total stock of demersal fish is determined mostly by state of the cod stock. It was very high in the middle 1980s, then had a significant decline in the late 1990s - early 2000s, but rises again since the middle 2000s. A considerable part of the mass demersal species migrate in summer from the Western Bering Sea to the Chukchi zone for feeding that is the background for significant fluctuations of their biomass assessments, which depend on the environments variability. The densest aggregations of the mass demersal fish form mainly in the area between Cape Olyutorsky and Cape Navarin and in the Anadyr Bay in the waters of the Navarin Current.

Data on age of mass maturing and biomass culmination for pacific herring from the Gizhiga-Kamchatka population in conditions of active fishery are presented. Dynamics of its age structure is considered for the periods before active fishery and after its renewal. After the fishery renewal, the portions of mature fish by age groups had increased and the age of mass maturing had decreased, the body length of mass maturing became smaller, the mean body length and weight had decreased for the majority of age groups, and the rate of maturing had increased for females. The established commercial measure corresponds well to recent biological structure of the population. There is concluded that the active fishery during five years has no negative impact on the state of the Gizhiga-Kamchatka population of herring.

Genetic variation among spawning groups of pacific herring from different spawning grounds in the northwestern Okhotsk Sea and Lake Ainskoye (Sakhalin Island) is assessed by 11 microsatellite loci. All loci were polymorphic. Genetic differentiation of the herring from the Okhotsk Sea was statistically significant, the pairwise genetic differentiation F_ST varied in the range of 0.0-0.4 that suggested existence of at least two local stocks. The herring from Lake Ainskoye was clearly different from the Okhotsk Sea herring.

Some patterns in dynamics of catch and biological parameters of pink salmon Oncorhynchus gorbuscha returned to the southeastern coast of Sakhalin Island and the Aniva Bay in 2014 (additional peak in the return abundance and unusual increase in relative fecundity of females in the second half of the return) could be interpreted as presence of the fish from Kuril Islands. This hypothesis was proven by the scale structure analysis, using the known difference between the pink salmon from southern Sakhalin and Iturup Island by the total number of sclerites and the depth of the local minimum in the first eight intersclerite distances caused by different environments. The fish of Kuril origin was found in all samples collected on the southeastern coast of Sakhalin on August 6, 7, 14, and 18, with its portion increasing in later catches, and in the sample collected in the Ostrovka River on the eastern shore of the Aniva Bay on August 18, but wasn’t found in the sample collected in the same site on August 25, and only a small portion of the fish of Kuril origin was found in the marine sample taken at the Busse Lagoon. The pink salmon in the Kura River on the western shore of the Aniva Bay had mixed origin, too, but without signs of the Kuril origin. This is the first real evidence of the salmon straying and the hypothesis of fluctuating stocks of pink salmon obtained with the ichthyological methods, though possibility of the straying is debating many years. This phenomenon has high theoretical and practical importance. The new findings show that mass movement of pink salmon between different reproduction regions is quite real, though maybe it happens rarely, presumably during the shift of domination between the odd- and even-year broodlines. The straying of low intensity may be invisible with routine methods, that’s why thorough monitoring of pink salmon stocks in different areas of its reproduction is necessary for understanding its population structure and dynamics, including detailed environmental, ichthyological and genetic studies.

In the mesohaline estuary of the Avvakumovka River (43°42’ N), the clam Corbicula japonica inhabits sand and silt-sandy grounds on the depths > 0.5 m in the main channel and tributaries from the mouth to 5 km upstream. The highest density (up to 175 ind./m², 3882 g/m²) is observed in the mouths of tributaries with low velocity of the flow. Settlements in different parts of estuary differ by abundance of C. japonica , its size-age structure, and growth rates. The maximum observed shell size was 53 mm, the maximum weight of mollusk - 43 g, the maximum age - 13 years. The growth rate variability within the estuary is comparable with its latitudinal variation. The clam has the maximal linear increment of shell length in the first year of its life and the maximal weight increment - in the age of 5-7 years. It reaches the commercial size (shell length 20 mm) in 3-4 years old. The annual secondary production of C. japonica does not exceed 17.8 gС/m², with P/B-ratio 0.37. Its annual consumption exceeds its biomass in 2.0-2.4 times. Corbicula japonica in the Avvakumovka River is practically unaffected by genotoxic influence; the estuary is defined as a clean, low-polluted area.

Description of the mackerel Scomberomorus niphonius caught in the Vityaz Bay (Peter the Great Bay, Japan Sea) on September 19, 2015.

The final issue in the series of studies on trophic ecology of pacific salmons in the Bering Sea conducted by planktonologists of Pacific Fish. Res. Center (TINRO) for NPAFC. Salmons dwell in the upper epipelagic layer and feed mainly in the daytime by large-sized zooplankton that is more abundant in the upper pelagic layer as compared with the lower pelagic layer in summer-fall season. The zooplankton and nekton species dominant in the salmon diet are determined on the base of 8,000 plankton samples and 45,000 samples of salmon stomachs. Two periods with different environments are revealed in the Bering Sea in the early 21 century: the relatively warm period of 2000-2006 and the relatively cold period of 2007-2012. The regime shift between them affected the plankton community and trophic ecology of salmon, though not by means of water cooling directly but presumably because of the water circulation change. Food composition is determined for each size group of salmons in both periods, by biostatistical areas and bathymetric ranges. Zooplankton grazing by salmons increased significantly in all areas during the cold period, whereas the nekton grazing decreased, but their total consumption did not change much. Transition to the next warm period since 2013 does not affect negatively to the salmon food base; their diet changes significantly but within the list of preferable species. Feeding intensity of pink, chum, and sockeye salmons was similar in any period, as well as in the 2014-2015, food deficit was never observed. The salmons show a great plasticity in feeding: in general, their diet corresponds to the structure of plankton community, though the portion of nekton increases with the age. Large-sized salmons consume a large-sized prey and need more time for its complete digestion, so there is necessary to apply reduction coefficients in calculation of their daily food rations. N​utritional needs of all salmon stocks are estimated for summer-fall season and offered as a guideline for evaluation their load on the food base and their food security for certain spatial and temporal circumstances.

On the basis of plankton surveys, conducted in the north-western Bering Sea in 2010-2015, the production characteristics of zooplankton were calculated and analyzed. Zooplankton was divided into two trophic groups: predatory (mainly chaetognaths and hyperiids) and non-predatory (copepods and euphausiids) zooplankton. Considerable variations of zooplankton production parameters were observed in autumn period. This is due to the inter-annual dynamics of regional patterns of the size, taxonomic and trophic structure of zooplankton.The sharp decline in the copepod biomass after 2011 and the significant reduction in the biomass of euphausiids in 2013 were characteristic for the considered period in this region. All these features of the dynamics of copepods and euphausiids had an influence on the value of zooplankton production. The highest non-predatory zooplankton production was in 2010-2011 (up to 5081 mg/m³); the lowest, in 2012-2014 (up to 2716 mg/m³). Production of predatory zooplankton was the most significant in 2013 in the waters of the eastern part of the Gulf of Anadyr; it was associated with the presence of Themisto libellula . In general, non-predatory zooplankton in the north-western Bering Sea produced from 14.8 to 53.1 million tons during autumn; predatory zooplankton, from 5.0 to 14.2 million tons.

Content of the metals Fe, Mn, Ni, Pb, Zn, Cd, and Cu was determined in the water, suspended matter, plankton organisms and bivalves collected in the brackish-water lagoon lakes on the coast of the Japan Sea in July 2011-2012, August 2013, and July 2014. The lakes are located in the sparsely populated area of eastern Sikhote-Alin including the Sikhote-Alin biosphere nature reserve. The content of Fe, Mn, Ni, and Pb has a tendency to decrease along the trophic chain that is conditioned by prevalence of their suspended forms over dissolved ones in the water and decreasing of the surface : weight ratio with size of living organisms. On the contrary, the content of Cu, Zn and Cd is rather stable along the food chain because of prevalence of their dissolved forms and low content in the suspended organic matter.

Long-term variability of the cold subsurface water (CSW) in the Okhotsk Sea is analyzed on the base of all available oceanographic data collected in March through August of 1946-2015 (total 65,742 stations). The Integral Heat Content (IHC) is calculated for each station and average annual IHC anomalies of the cold subsurface water are determined by month and by 2-degree grid. The IHC anomaly series are analyzed using the EOF analysis. Cycles with period of approximately 30 years are revealed in the variations of the subsurface layer heat content. Thus, in the 1946-1950, its temperature decreased, but it grew since 2009-2010 to 2015. The warming of CSW was also observed in the 1951-1964 and 1978-1994, while the cooling was in the 1965-1977 and 1995-2008. Based on this criterion, the CSW thermal condition in certain years is classified as «extremely cold» in 2001, as «cold» in 1949, 1950, 1951, 1958, 1959, 1960, 1966, 1967, 1969, 1973, 1976, 1977, 1978, 1980, 1999, 2000, 2010, 2012, as «normal» in 1946, 1952, 1953, 1954, 1955, 1957, 1961, 1962, 1965, 1970, 1971, 1972, 1975, 1979, 1982, 1983, 1985, 1986, 1988, 1989, 1990, 1993, 1995, 1996, 1998, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2013, 2014, as «warm» in 1948, 1956, 1964, 1968, 1974, 1981, 1984, 1987, 1991, 1992, 1994, 1997, 2015, and as «extremely warm» in 1963. Statistically significant correlation is found between changes of the CSW thermal conditions and long-term variations of atmosphere and ocean climate indices, as well as local patterns of the atmosphere-ice-ocean interaction in the Okhotsk Sea and adjacent onshore and offshore areas of Asia and the Pacific Ocean.

The sea ice characteristics and drift patterns are considered for the Okhotsk Sea shelf at Magadan on retrospective data of the ice observations and satellite images. Spatial heterogeneity of the sea ice parameters and its drift is shown. Phases of the sea ice seasonal variation in this area could differ from year to year in 10-20 days on spatial scale of hundreds kilometers and the ice age, form and concentration vary in 10-50 % within the seasonal cycle. The ice drift velocity averaged for 6 or 10 days varied from 1.3 to 12.5 km/day in the winter of 2015; the highest velocity 0.75 m/s was registered on March 12 by comparing two satellite images with time interval of 110 min.

Feeding habits of masu salmon Oncorhynchus masou in the Okhotsk Sea is investigated. Its main prey in fall season is fish, amphipods, and euphausiids. However, the diet composition depends on the area: for masu with size of 30-40 cm it is mainly fish in the biostatistical districts 8 and 11 and zooplankton in other areas; besides, the zooplankton prey is replaced by fish for elder and larger salmons. The stomach fullness has significant circadian rhythm with one main maximum (70-700 ‱) and one minor peak. The main maximum was observed at 21 o’clock in 2002 but at 15 o’clock in 2006 and at 18 o’clock in 2009 and 2015 (local time).

Underwater observations were conducted to assess the impact of the research Danish seine elements on behavior of walleye pollock Theragra chalcogramma in its active zone. The underwater video equipment was installed on specially designed and constructed experimental platform and on elements of the Danish seine. In the experiment with pollock, the experimental platform demonstrated its low efficiency, however, it could be used for observations on sedentary benthic organisms on homogeneous soils without sharp changes in the terrain. With the equipment installed directly on the Danish seine, high efficiency of the seine ropes was observed: up to 92 % of fish from encircled volume remained in the towed area. Taking into account this estimation and features of fish biomass distribution, the coefficient of catchability for Danish seine is determined as 0.40 ± 0.15.

Methods of proteolytic enzymes isolation from muscle tissue and viscera of pond fish are viewed and their properties are investigated. Efficiency of enzymatic processes is determined by physical and chemical characteristics of the enzymes and, first of all, by their activity and stability. The cathepsins from muscle tissue of most pond fish are acidic and have the highest activity under pH 4.5-5.0. The substrate specificity of this enzyme complex predetermines its possible usage in pickling, particularly for reducing its time and improving organoleptic parameters of the product.

Influence of the time of thermal treatment of sardinella backbones on organoleptic characteristics, water-holding capacity, and size of particles for the minced bones is investigated. Rational parameters for the thermal treatment of backbones are determined. Effect of vegetable additives of Jerusalem artichoke on functional and technological properties of the minced bone systems is examined. Safety indices of the food produced from thermally treated fish wastes are evaluated.

Biotechnological stage in technology of fodder products of starfish is substantiated. The starfishes Evasterias echinosoma and Patiria pectinifera caught in the Severnaya Bay (Primorye coast of the Japan Sea) are used in the experiments on enzymic hydrolysis for production of the fodder additive with high biological value. The hydrolysis provides the more accessible forms of nutrients for animals and birds. Impacts of the enzyme preparation concentration, temperature, pH, time of hydrolysis, and water duty on efficiency of enzymic hydrolysis are tested in the experiments; these parameters influence on the amount of accumulated amino nitrogen and on the hydrolysis degree is evaluated. The following rational values are determined for the parameters in the process of protein-mineral fodder additive production: concentration of enzyme collagenase preparation - 0.25-1.00 %; time of treatment - 2-4 hours; temperature - 45-55^oC; pH - 6.0; water duty - 0.2.