Some conceptions on marine ecology of pacific salmons (Oncorhynchus spp.), established in the second half of the last century, are discussed from critical position, as overemphasizing of the sea surface temperature influence on distribution of salmons and formation of their year-classes strength, deficiency of food (particularly in winter time) and fierce competition for food, pink salmon «suppression» over other salmon species and own adjacent generations, limited carrying capacity of the Subarctic zone for salmons, distortion of the epipelagic communities structure in the North Pacific by mass artificial reproduction of chum salmon, etc. Most of these ideas have not been confirmed by the data of long-term monitoring in complex marine expeditions conducted by Pacific Fish. Res. Center (TINRO) in the Far-Eastern Seas and adjacent North Pacific waters since the 1980s till nowadays. The data show that pacific salmons are very ecologically plastic species with wide temperature range of habitat. Salmons are able to considerable vertical migrations crossing easily the temperature gradient zones and different water masses. They have wide feeding spectra. Migrating dispersed, they successfully get their ration, even in vast areas with relatively low concentration of prey (macroplankton and small nekton). Total biomass of all species of pacific salmons in the North Pacific does not exceed 4-5 million tons (1.5-2.0 million tons in the Russian waters), whereas the stocks of other mass species of nekton are hundreds of millions of tons. The salmons consume 1.0-5.0 % of the total consumption by nekton in the epipelagic layer in the western Bering Sea, 0.5-1.0 % in the Okhotsk Sea, 5.0-15.0 % at East Kamchatka, and less than 1 % in the Pacific waters at Kuril Islands, So, the role of pacific salmons in trophic nets of the Subarctic waters is rather moderate. Therefore, neither pink salmon, nor chum salmon can be seriously considered as the species responsible for reorganization of large ecosystems and fluctuating of other mass nekton species.

Species diversity and other integral parameters of zooplankton community in the Japan, Okhotsk, Bering, Chukchi seas and adjacent Pacific waters (total area close to 7.0^. 10⁶ km²) are compared on the data obtained in the large-scale surveys conducted by Pacific Fish. Res. Center (TINRO) in 1984-2013. Standard Juday net with mesh size 0.186 mm and mouth area 0.1 m² was used for sampling. Among four seas, the Chukchi Sea takes the 1^st place by abundance (ind./m³) and biomass (mg/m³) of zooplankton, 2^nd by species evenness, 3^rd by mean size of organisms, and the last by species richness and diversity. The Bering Sea is the 1^st by mean size of animals, 2^nd by species richness, diversity and biomass, 3^rd by abundance, and the last by species evenness. The Okhotsk Sea takes the 2^nd place by mean size of zooplankton, the last by its abundance, and the 3^rd by other parameters. The Japan Sea is the 1^st by species richness, evenness and diversity, 2^nd by abundance, and the last by mean size of zooplankton and therefore by its biomass. Zooplankton in the Pacific waters has the lowest abundance, but its biomass is higher there in comparison with the Japan Sea. Species richness is the highest in the Pacific, but species diversity is higher there than in the Chukchi Sea and species evenness is the lowest. Mean size of zooplankton organisms in the Pacific is rather large but smaller than in the Bering Sea. In general, zooplankton abundance increases northward in accordance with nutrients supply, as well as the mean size of animals (with exclusion of the Chukchi Sea), but uniformity of the species abundance has opposite tendency (except the Chukchi Sea again). The rank in biodiversity coincides with the rank in species richness. The latter decreases from south to north (with exclusion of the Okhotsk Sea), but depends strongly on size of the surveyed area and surveyed volume of water. Some unexpected statistically significant relationships are found between the integral parameters of zooplankton and these parameters for pelagic and bottom macrofauna which have not yet any rational interpretation.

Cited and archive data on fecundity of 31 flatfish species are generalized for the North Pacific. General characterization of the fecundity is presented and correlation between absolute individual fecundity of the females and their body length or age is analyzed and formalized in equation form. Spatial variability of fecundity is described for different species: pacific halibut and starry flounder have the highest absolute fecundity in the eastern Bering Sea and Okhotsk Sea, greenland halibut, yellowfin sole, alaska plaice, sakhalin flounder, longhead dab, and flathead sole - in the Okhotsk Sea, northern rock sole - in the waters at East and West Kamchatka. kamchatka flounder - in the Bering Sea, arrowtooth flounder - in the Pacific waters at North America. So, the Okhotsk Sea is the area where the absolute fecundity of majority wide-spread flatfish species can reach the maximal level. However, the maximal fecundity of longsnouted flounder is higher in the Japan Sea than in the Okhotsk Sea.

Comparative analysis is made for absolute, species-specific and total fecundity of 31 flatfish species in the North Pacific from North America to the Japan Sea. Normally the individuals of larger size have higher fecundity. Similarity between the species by fecundity dynamics in dependence on body length and age is evaluated. Significance of the absolute fecundity for abundance or distribution of the species is discussed. Generally, the species with medium or high fecundity are more abundant than those with low number of eggs. The widest distribution is intrinsic for flatfish species with medium length of the early pelagic stage of their life.

General patterns of the pacific saury feeding migrations in the North-West Pacific are determined on results of fishing operations conducted by a group of Russian fishery vessels in June-November, 2014. The main route of migration in June-July was directed westward and northwestward, to the open ocean. In the late summer and early autumn the saury migrated southwestward along the Oyashio Front. Towards the end of the feeding period, the main portion of large-sized saury moved along the 1^st branch of Oyashio to the EEZ of Japan and its other portion moved along the 2^nd branch of Oyashio to the open ocean waters. Intensity of the southwestward migrations varies from year to year in wide range in dependence on oceanographic conditions.

The data of pelagic and bottom surveys on pacific herring in the northwestern Bering Sea obtained in 2010-2015 and its stock assessments by different methods are compared. Some biological parameters of the herring are presented and its spatial distribution and migrations are described. The pelagic surveys with stepped trawling and the bottom trawl surveys are concluded as the best for the herring stock assessment and biological characteristic. The stock state in the 2010-2015 is determined as high abundant due to mass migration of herring from the eastern Bering Sea to its northwestern part that starts in June under certain oceanographic conditions. Different modes of the herring feeding migration are revealed for periods of its high and low stock. The results are used for the herring fishery regulation in the northwestern Bering Sea.

Population of pale sea urchin Strongylocentrotus pallidus in Peter the Great Bay is investigated. The samples for its size structure and distribution were collected at the depth from 5 to 700 m in July 2013, 2014 and in April 2015 and the samples for the state of gonads, intestines and age structure - at the depths of 41, 69, 280, 346, and 670 m in early April 2015. The size structure at different depths is significantly different: the large individuals with average size of 70.0 mm (portion of commercial ones 98 %) occupy mainly the middle shelf area with the depths of 55-100 m, deeper at the depths of 100-200 m the portion of commercial urchins is lower (67 % in 2014 and 92 % in 2015), and the continental slope (depth > 200 m) is occupied by mainly (77-96 %) non-commercial individuals with average size of 35.5 mm. Age of sea urchins was determined by the growth zones on plates of their shells processed by Jensen method and varied from 3 to 12 years. The growth rate of sea urchins from the shelf areas was approximately in 1.5 times higher as compared with those from the continental slope, primarily due to different conditions of feeding. The gonads cellular composition was defined for the samples of 50 cells per female. The cells were differentiated in the categories of oocytes proliferation, oocytes differentiation, and mature eggs, and the gonad maturity stage was determined by domination of these categories, taking into accounts the S. pallidus reproductive cycle. In spring, the sea urchins from the shelf areas (depths of 41 and 69 m) were generally more mature as compared with those from the continental slope (depths of 280 and 346 m). However, correlation between the gonadal index and depth of habitat was not significant because the mature females were sampled in any depth. Composition of intestinal content and food components were determined visually, looking the bolus under binocular microscope. The sea urchins intestines were mostly filled with detritus at the depth of 41 m, sponges (Suberites sp.) at the depth of 69 m (70 % of cases), and unedible substances as silt and sand at the depth of 280, 346 and 670 m, minor fractions were the algal litter, remains of crustaceans, and detritus.

Internal organs of black-backed shad are examined by histological analysis. Wide range of pathologies is found, which are supposedly caused by chronic environmental pollution. The pathologies of tissue and cellular levels have common features but various symptoms, as edema, hemorrhage, necrosis, inflammation, connective tissue proliferation, proliferative changes in the epithelium. The gills, liver; kidney, and intestines are the most sensitive to negative impacts of environments.

Hypothesis on fluctuating stocks of pink salmon was proposed 30 years ago by M.K. Glubokovsky and L.A. Zhivotovsky. Some stages of its development are analyzed in compare with traditional approach of local stocks. There is concluded that experimental verification of the basic theoretical assumptions of this hypothesis are required.

The community of Phyllospadix iwatensis is studied using materials from expeditions of A.V. Zhirmunsky Institute of Marine Biology (National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences) and archive data (1949-2013) of the Laboratory of Chorology covering the species habitat area from Peter the Great Bay in the south to middle Kuril Islands in the north. The core of the community is identified. It has changing species composition; the changes correspond to geographical boundaries of the cenotic systems of Peter the Great Bay, the Lesser Kuril Islands, and Iturup Island. However, these boundaries do not coincide with the boundaries of the species-edificator habitat that embraces several cenotic systems. Spatial alterations of the cenotic systems are caused by landscape changes conditioned by general geomorphological situation and ecological conditions in the intertidal zone.

Trophic links between nekton and plankton are analyzed using the data collected in trawl surveys conducted by Pacific Fish. Res. Center (TINRO) in the Pacific waters at Kuril Islands and East Kamchatka in June-July of 2004-2016 and in the central and western parts of the Subarctic Front zone and adjacent subarctic waters in February-April of 2009-2011. Spatial, seasonal and interannual dynamics of nekton communities are detected, as well as changes in their composition and abundance. The most significant changes were caused by mass migrations of subtropical species, as in summer of 2014-2016. In these cases, new components were involved in the food web and energy flows between the low and upper trophic levels were changed, in the first place concerning to copepods, then to euphausiids, amphipods, and small-sized nekton prey. There were no such significant interannual changes in the energy flows in winter. The estimates of daily and seasonal energy flows between low and upper trophic levels, as well as the consumption rate of forage resources indicate no excess of allowable grazing pressure upon forage resources in the upper pelagic layer of the surveyed areas.

Collecting the spat of good quality and enough quantity, as the seeding material for commercial cultivation of scallop Mizuhopecten yessoensis Jay, 1857, is one of the main problems for aquaculture farms in Primorye. In the eastern Ussuri Bay, pacific mussel Mytilus trossulus Gould, 1850 is the dominant species which larvae settle on the systems designed for the scallop spat collecting. Its spat quantity in collectors exceeds the scallop spat number in 5-65 times, with the biomass in 3-140 times higher. The scallop spat survival dependence on abundance of the mussel spat is investigated but any correlation is not detected. However, general quality of the scallop spat in the farms in the Ussuri Bay is poor that could be a reason of its low survival on further stages of cultivation: mean size of the scallop spat here is close to the lower acceptable limit of the standard range (10-11 mm). Besides, food resources for the scallop spat could be limited in the years with high abundance of the mussel spat.

Feeding of masu parr in the natural river habitat on 8-9 days after their release from hatchery is considered on the data obtained in the Lyutoga River tributaries in 2014-2015. No fish with empty stomach were found that indicated successful transition of artificially hatched fish to feeding in the natural environments. More than 40 species of prey were found in their stomachs, mostly terrestrial and aerial invertebrates and the river bottom dwellers as mayflies and chironomids. The diet corresponded to biotopes features. For better feeding (higher stomach filling) gradual releasing is recommended over wide areas by the parties no more than 4,000 ind. The juveniles should be transported in isothermic boxes to the lower or middle parts of streams and in packages with oxygen (for 600-1000 ind. each) to the upper streams. Involving of volunteers from fishermen to the releasing is desirable that attracts additional attention to the species protection.

A hydrodynamic problem for the longline system «anchor-tightrope» in resting fluid is formulated and solved on base of the theory of dynamics for systems with variable mass. The system of initial differential equations is solved by means of numerical methods using the software designed in MathCad-14 environment; parameters of the «anchor-tightrope» system in the process of submersion are calculated. Dependence of the time and velocity of submersion on type of anchor is analyzed taking into account the hydrodynamic forces dependence on Reynolds number. Influence of inertia force is determined. Cited results for dependence of the submersion time for fishing gear elements on depth are overviewed.

The raw material charge coefficients (RCC) are calculated for processing of female red king crabs from the coastal Barents Sea. The percentage outcome for limb clusters is 37.49 % (RCC 2.702), for meat - 19.63 % (RCC 5.163), and for merus - 6.25 % (RCC 16.304). The coefficients are lower as compared with the males of red king crab. These data let us to assess more accurately the number of crabs processed after illegal poaching landing.

Effects of spicy oil extracts on thermal resistance of microorganisms in canned cephalopods in oil or with addition of oil, on duration of the sterilization, and on quality of finished products are investigated. Thermal resistance of the spores decreased after the vegetable oil substitution by the spicy oil extract, so the time of sterilizing under the temperature of 115^оC could be reduced in 5-10 minutes that facilitates inhibition of residual microflora, including the spore forms, in the finished product and provides better bioavailability of its protein component.

New method for determination of organochlorine pesticides (DDT and its metabolites, HCH and its isomers) is presented. The method includes a liquid-liquid extraction of pesticides under ultrasound and the substance analysis by gas-liquid chromatography. The degree of DDT and γ-HCH extracting from tissues of marine organisms is (78 ± 2) % and (91 ± 2) %, respectively. The total content of organochlorine pesticides in muscles of walleye pollock from the Okhotsk Sea is evaluated by this method in the range from 25 to 73 pg/g of lipids.