Peter the Great Bay (PGB) was not known to Europeans for a long time. The first European ship reached PGB in 1852. She was the French corvette Capricieuse commanded by captain G. de Rocquemaurel who was sent by his government for exploring the western coast of the Japan Sea; actually he had described the Posyet Bay only. Later the British HMS Winchester and Barracuda visited PGB in August, 1856. They discovered the Golden Horn Bay, them as Port May, and gave names to many other geographical locations. Large Russian expedition of 7 vessels was sent to Primorye coast under the leadership of N.N. Muravyov-Amursky, the Governor-General of Eastern Siberia, in the summer of 1859. They described thoroughly the entire PGB and changed many (not all) foreign geographical names to Russian ones. Scientific researches in the Japan Sea were started soon by L.I. Schrenk, who summarized the results of Russian observations in two books published in 1869 and 1874. Great success in understanding of oceanographic regime was the work of S.O. Makarov «The «Vitiaz» and the Pacific Ocean» (1894). S. Ogura created in 1927 the general chart of currents in the Japan Sea on the base of Japanese observations in 1900–1911 that was more detailed and comprehensive than the first chart of L.I. Shrenk. Moreover, S. Ogura plotted the water temperature and salinity distribution over the whole Japan Sea for February and August. Oceanographic studies in PGB were made in 1920s by K.A. Gomoyunov, the first professional oceanographer who lived constantly in the Russian Far East; he began from the Amur Bay survey in the summer of 1925. The USSR Hydrographic Office conducted the oceanographic survey in PGB and the Tatar Strait in 1926–1928, with measuring of temperature, salinity, dissolved oxygen content, pH, and water transparency, with the deepest measurements at the depth of 3500 m. In 1932, the Pacific Res. Inst. of Fisheries in Vladivostok together with the State Hydrographic Institute in Leningrad organized the large-scale Pacific expedition that covered all Far-Eastern Seas. In the framework of this expedition, the 5 cruises of RV Rossinante to the Japan Sea headed by N.I. Tarasov explored PGB, too, that allowed to analyze seasonal variations of temperature, salinity, oxygen content, and currents. Oceanographic researches in the Japan Sea became more active in the times of WWII, 4 small research vessels made observations at Primorye coast every month from April to October under general supervision of A.M. Batalin; in total, more than 100 exits to the sea were recorded in 1941–1946. The data collected in those years was the basis for the big atlas of the Japan Sea created under the leadership of A.I. Rumyantsev and published in 1951.

New method is proposed for operational differentiation of pink salmon runs with different time of spawning and different state of gonads measured quantitatively with a gonad-somatic index. Results of this new method and traditional methods of differentiating are compared. The conception of spatial niches in the Pacific waters adjacent to Kuril Islands for certain temporal groupings of the Okhotsk Sea pink salmon is critically revised on the base of these new results. The runs cannot be separated using any fixed value of the gonad-somatic index. The zones of different groupings could be spatially overlapped. The method is tested on the data of trawl survey conducted aboard RV Professor Kaganovsky in May-July 2018, during anadromous migration of pink salmon, and shows a high compliance with the regional groupings ratio determined on the data of pink salmon catch in the Okhotsk Sea and their escapement to rivers. Tendency of the late-maturing forms of pink salmon to migrate through the southern Kuril waters is confirmed, whereas the portion of early-maturing pink has increased toward the Ocean.

Atka mackerel Pleurogrammus monopterygius is one of the mass species of fam. Hexagrammidae that inhabits the boreal and subarctic waters of the North Pacific and forms two large populations in its western and eastern parts. Reproductive range of the eastern, Aleutian population extends from the Gulf of Alaska, along Aleutian Islands to Commander Islands, with the main spawning grounds at the Aleutians and in the southeastern Bering Sea. From these areas, the fish at early stages of ontogenesis spread widely in system of the Bering Sea currents to the western-southwestern Bering Sea, where the atka mackerel aggregations are formed on the external shelf at prominent capes, as Cape Olyutorsky. Dynamics of the atka mackerel stock in the Olyutorsky-Navarinsky area in 1994–2019 is presented on the base of bottom trawl surveys, fishery statistics, and open NOAA data. After the period of low stock in the middle 1990s, the atka mackerel abundance increased sharply to the maximum in 2006–2008, when the spawning stock in this area was about 9.5 . 103 t and the commercial stock about 14.0 . 10³ t. Since that time, trend to decreasing is observed, with the spawning stock 3.6 . 10³ t and the commercial stock 5.6 . 10³ t in 2013, and recent stabilization at the low level with slight decline continuing. A possible reason of the sharp increase in 2000s could be the intensive transport of the atka mackerel juveniles from the main spawning grounds at Aleutian Islands to the area at Cape Olyutorsky. The catches of atka mackerel in the Olyutorsky-Navarinsky area in 1994–2018 corresponded well with its stock dynamics.

Dynamics of the greenland halibut biomass in the fishery districts of the Okhotsk Sea (or subzones) is considered. The biomass variation in the East-Sakhalin subzone has a significant (p < 0.05) negative correlation with the number of 3+ fish in other subzones, with the time lag of 3 years (r = –0.53) and 4 years (r = –0.49), that is interpreted as alternative distribution of the halibut recruitment from the common spawning area either to this district or other ones. From other hand, the recruits abundance in other districts is significantly and positively associated (r = 0.52, p < 0.05) with the index of zonal atmosphere transfer in January and with the index of meridional atmosphere transfer in March of the years of hatching. The recruitment dependence on the spawning stock could be explained by Beaverton-Holt equation with the residuals significantly and positively (r = 0.64, p = 0.03) related with the Arctic Oscillation index. Transport of the eggs, larvae and juveniles of greenland halibut from the spawning grounds at western Kamchatka to the western Okhotsk Sea is considered as the mechanism of its recruitment distribution between the districts in relation with atmospheric indices. The transport was simulated for 1993–2017 using the circulation model JCOPE2 as the movement of 250,000 artificial passive particles, imitating eggs and larvae, with water flows at the depth 40–50 m where their main aggregations are supposed. The particles were released in the area at western Kamchatka where the maximal concentration of spawning females occurred. Number of the particles reached the sections off eastern Sakhalin and their arrival times were computed, their pathways were tracked. The portion of particles released in December and reached northern Sakhalin within 150 days changed in significant positive correlation (r = 0.44, p < 0.05) with dynamics of the halibut stock in the East-Sakhalin subzone, with the time lag 6 years. Even closer correlation (r = 0.94, p < 0.05) could be found for the optimum income of the particles released in October or November in the general additive model of the stock. Using the model results for the recent years, the greenland halibut stock decreasing in the East-Sakhalin subzone is forecasted for the next 6 years.

Number of the pink salmon fry migrating downstream from their spawning grounds in the control rivers in 2019 is assessed as 17546.2 . 10³ and 14795.7 . 10³ ind. for the Dagi and Bolshoi Khuzi Rivers (northeastern Sakhalin), as 89.1 . 10³ and 2636.1 . 10³ ind. for the Poronai River tributaries — the Kholodny and Orlovka, as 2759.8 . 10³ and 21456.0 . 10³ ind. for the Lazovaya and Pugachevka Rivers (western coast of the Patience/Terpeniya Bay), as 5803.8 . 103 and 19020.0 . 10³ ind. for the Voznesenka and Ochepuha Rivers (southeastern Sakhalin), as 1822.4 . 10³ and 2139.0 . 10³ for the Taranai and Kura Rivers (Aniva Bay coast), and as 15834.1 . 10³ and 7626.1 . 10³ ind. for the Rybatskaya and Olya Rivers (Iturup Island), respectively. In all areas, the pink juveniles migrated from the spawning grounds earlier than usual, obviously because of accelerated development of the embryos in conditions of abnormally warm autumn. The number of juveniles migrated from all spawning grounds in the rivers of respective regions is estimated taking into account the escapement of pink salmon spawners and the downstream migration index determined for the control rivers (ratio of the spawners escapement and the number of subsequent downstream migrating juveniles): the total number for the natural spawning grounds is estimated as 1168.9 . 10⁶ ind. for the rivers of the eastern coast of Sakhalin (including the Aniva Bay) and 471.1 . 10⁶ ind. for the rivers of Iturup Island (Okhotsk Sea coast). Additional 141.3 . 10⁶ ind. were released from artificial hatcheries of eastern Sakhalin and 122.0 . 10⁶ ind. — from artificial hatcheries of Iturup Island. The downstream migration is considered as highly abundant for northeastern Sakhalin and Iturup Island, but is insufficiently abundant for the Patience/Terpeniya Bay and Aniva Bay where the landings of this generation should be limited. The pink salmon return to southeastern Sakhalin in 2020 is expected to be better than in 2018 due to satisfactory abundance of the juveniles from natural spawning grounds.

Size and sex structure of mysid Neomysis mirabilis in Peter the Great Bay is studied. The net samples (160 and 260 per year) were collected at the depth of 0.5–2.0 m in the southern external part of the secondary Amur Bay (at Popov and Reineke Islands) and in its northern internal part, over the total area of approximately 3 km² , in the daytime in May-September from 2014 to 2017. The catch was recalculated per 1 m³ of water. The water temperature was measured and weather conditions were recorded. All mysids (2926 ind.) were measured under binocular microscope with accuracy of 0.1 mm, weighted by torsion scales with accuracy of 1 mg, and separated to males, females and juveniles. The females were differentiated by 5 stages of development: 1) immature females with oostegetic rudiments, 2) oviparous females, 3) females with embryos in the marsupia bags without stalk-eyed with black pigment, 4) females with embryos in marsupia bags with black eyes, 5) spawned females with empty marsupii. The females prevailed: 71.3–97.0 % in the southern Amur Bay and 39.0–56.7 % in the northern Amur Bay, while the portion of males was 2.2–28.7 % and 20.9–43.3 %, accordingly. The body length varied from 3.0 to 23.5 mm; the females and males had the same sizes, on average 14.5–15.4 mm in the southern Amur Bay and 8.3–11.2 mm in the northern Amur Bay, with slight decreasing from spring to summer. The spawning was extended in time because of several generations changing. Mysid females with eggs, their embryos at different stages of development, and juveniles of different size were presented permanently. Aggregations of N. mirabilis formed for a short time starting in middle April — middle July in the southern Amur Bay and in middle May — late July in the northern Amur Bay. The mysid biomass in the aggregations was 3–5 g/m2 and 10–500 g/m² in these areas, respectively, that is appropriate for the commercial fishery. Spatial difference of the mysid biological parameters and abundance is explained by different environmental conditions in the internal and external areas of the Amur Bay.

Linear and weight growth of amur flathead asp Pseudaspius leptocephalus is described on the base of the measurements data collected on the lower Amur (from Nizhneleninskoe village to the mouth) in 2004–2018, using von Bertalanffy growth equation. Age was determined for 2240 fish including 1061 females and 528 males. The main specific features of the amur flathead asp growth are the absence of sexual dimorphism in linear growth rate and the absence of the body length differences between females and males, except of the eldest fish. However, the sexual dimorphism is found for the weight growth. A compensatory growth is noted for the amur flathead asp. The amur flathead asp parameters have some geographical variability.

Application of CICE ice model for the mid-term (days) forecasting in the Bering Sea is considered, with short description of the model. Dependence of the sea surface temperature on the air temperature forecasted by GFS (Global Forecasting System) is determined. The ice concentration, ice cover, and the dates of ice formation are forecasted for the winter 2018/2019 using the model; its practical applicability is concluded.

Species composition and abundance of phytoplankton, chlorophyll a concentration and chemical parameters were monitored at the coast of Russky Island in the Paris Bay, the shallow secondary inlet of Peter the Great Bay in 2014–2015. In total, 103 species and intraspecific taxa of microalgae from 4 classes are identified. Dynamics of phytoplankton abundance did not coincide with the dynamics of chlorophyll a concentration. The abundance varied from 1.3 . 10³ cells/L to 1.9 . 10⁶ cells/L and chlorophyll a concentration changed in the range 0.21–6.08 mg/dm³ . Nutrients had the following concentrations: DSi 0.7–41.8 µM/L, DIN 0.0–7.1 µM/L, DIP 0.0–0.7 µM/L. Dynamics of microalgae density had no common seasonal pattern in 2014 and 2015, though seasonal dynamics of chlorophyll a, as well as variations of nutrients and other water properties were similar in both years.

Variability of the ice conditions in the Chukchi Sea is considered in various scales on the basis of all available information for 1950–2017. Its dependence on the atmospheric circulation patterns measured with the Arctic Oscillation index is shown. Tendency to the ice reducing has intensified in the early 21^st century in the Chukchi Sea that is accompanied with changes in its seasonal development, as shift of the ice destruction beginning from June to July, gradual increasing of the ice destruction rate till September, shift of the ice formation beginning from September to October, and delay of the ice spreading over entire sea area from November to December. Relationship of the ice conditions in the Chukchi Sea on summer phase of Arctic oscillation is detected: the maximum positive values of the index always correspond with heavy ice conditions, the minimum values of the index correspond with low-ice conditions only, and various ice conditions are observed in other years without neither positive nor negative extremities of Arctic oscillation. However, winter phase of Arctic oscillation does not affect on the ice conditions in the Chukchi Sea in June-November.

The water temperature influence on timing of spawning and the spat settling is considered for yesso scallop (Mizuhopecten (=Patinopecten) yessoensis Jay, 1857) in the Minonosok Bay (Posyet Bay, Peter the Great Bay) on the data of observations in 1970–2011. The date of the spawning start varied from May 1 to June 9 (within 40 days) and the start of the scallop spat settling onto collectors of marine farm varied from June 4 to July 5 (within 32 days). Usually the spawning was delayed in the years with long cold season and big sum of daily temperatures below zero or low mean temperature in winter months and April, when the pre-spawning period with the temperature above zero before May 1 was too short. The spat settling was delayed in the years with severe winter or low mean temperature in the pre-spawning period (r = –0.46); the early settling was observed in the years with early warming above 0^o C. The higher sum of positive daily temperatures accumulated till May 1 and till June 1, or within April and May, the earlier the spat settling on collectors (r = –0.58; –0.60; –0.55; –0.42, respectively). Prognostic equations for 10-day and 15-day forecasting of the dates of scallop spawning start and spat settling start are proposed and tested; accuracy of these forecasts is 70% for the spawning and 60 % for the spat settling.

Technique for analytical determining where the warp and backstrops should be attached to trawl board is proposed. The algorithm is developed for both triangular and quadrangular arrangement of the backstrops. Equations for calculation of the backstrops length are presented. Equilibrium stability conditions are defined for trawl doors.

Calculating of horizontal opening for a trawl mouth using the mathematical model of midwater trawl system developed by V.I. Gabryuk gives the errors 25.4 and 32.9 %, on average, for the trawls RT 57/360 m and RT 80/396 m, respectively. The significant errors cause doubts about correctness of this model equations application for calculation of the catch zone that is necessary for assessment of abundance and biomass of marine biological resources. New empirical equations are proposed on the basis of experimental data on shape of the rope-net shell of a midwater trawl, which allow to calculate the horizontal opening for its certain sections. The errors of the horizontal opening calculation with these new equations are 13.7 and 6.1 %, on average, for the trawls RT 57/360 m and RT 80/396 m, respectively, that is satisfactory for using them for calculating operational parameters of a midwater trawl system. The operational parameters of the midwater trawls RT 57/360 m and RT 80/396 m are calculated using Baranov’s approach with these new empirical equations, and their good adequacy is shown in the experiment with hydroacoustic measurements of the trawls mouth horizontal opening and the distance between the trawl doors conducted aboard RV TINRO and RV Professor Kaganovsky in the Okhotsk Sea in 2012–2015.

Processing of secondary raw materials from production of canned food «Sprats in oil» is considered. Comprehensive technology is developed for producing of protein, fat, and protein-mineral food additives from the sprat waste, as smoked sprat heads, using the method of high temperature hydrolysis. Rational method of the hydrolysis is substantiated, including preliminary separation of fat in fatty raw materials and its enzymatic-thermal treatment. The optimal values of temperature and duration of hydrolysis in autoclave are determined. Balances of organic substances are calculated for the main operations. This new technology was tested for fatty (24 %) and medium fat (13 %) raw materials under the temperature of 130–160 ^о С. The hydrolyzed organic mass was divided into fat, protein, and mineralized fractions and proteinfat emulsion. Food additives containing low molecular weight water-soluble peptides and high molecular weight insoluble proteins were extracted from the protein fraction by freeze-drying and mineral compounds were extracted from the mineral fraction by convective drying. The proteins were extracted more thoroughly, so the content of low molecular weight peptides in the freeze-dried hydrolysate of protein fraction was > 80 %. The produced additives have pleasant organoleptic properties and are sanitary safe. They are tested with some seafood, with positive result. The developed technology for processing of smoked waste is economically valuable and allows to solve the problem of pollution in the fish smoking industry.

The broth of sea cucumber was decolorized with mineral sorbents, as perlite and bentonite, and with chitosans of crab carapace and shrimp shell. The chitosans were the most effective in sorption and subsequent removal of the protein-pigment complex, providing the decolorization degree of 35–55 %. Besides, the content of glycosides in the broth was twice decreased. The amino sugars content changed in dependence on the chitosan origin: the chitosan of crab carapace did not influence on this parameter, but the chitosan of shrimp shell caused its halving. For the optimal combination of chemical compounds in the broth, the chitosan with high molecular weight (1300 kDa) extracted from crab carapace should be used for decolorizing. Preliminary fermentation of the broth with Protamex increased concentration of biologically active peptides with low molecular weight in the solution. The fermented and decolorized broth of sea cucumber has good organoleptic properties and high content of biologically active components, as glycosides, amino sugars and low molecular weight peptides, so could be used as the basis for nonalcoholic tonic drinks.

Fishery rent is assessed quantitatively for Russian Federation in 2014–2018. The annual rent value changed from 43 to 110 billion roubles, with the average amount of 88 billion roubles per year. On this basis, the net present value of non-cultivated aquatic living stocks is calculated using the data of official statistics, under assumption of 15 % return of capital. The fishery rent dynamics is determined mainly by the consumers demand (sales price) and the level of production cost. Other parameters, as the amount of capital, its profitability, etc., have smaller impact on the rent. Direct calculating of the aquatic living resources value using the data on total allowable catch (TAC) or commercial stock has large errors and uncertainty in contrast to the method of net present value that accounts the rental income. However, monetary valuation of aquatic living resources by this method requires a correct assessment of social discount rate because of its strong impact on the results of calculation. The social discount rate for Russian Federation varied in the 2014–2018 from 2.13 % to 3.73 % that is considered as a quite low level, typical for developed countries. Taking into account this correction, the value of non-cultivated aquatic living resources in Russian Federation is amounted as 1.4–4.7 trillion roubles in 2014–2018 that is considered as the minimal limit corresponded with an «ideal», undisturbed state of the system. In real, both value of fishery rent and value of fishery resources are affected by a number of officially unreported factors, such as discards and technological losses, which summary impact is assessed as 45 % of the fishery rent or 39 billion roubles per year, on average. Thus, the more realistic value of the non-cultivated aquatic living resources in Russia in 2014–2018 is 2.1–6.4 trillion roubles, on average 4.3 trillion roubles.