Based on results of the bottom trawl surveys on the shelf of the Petropavlovsk-Commander subzone in 1999, 2002, 2016–2018, three standard grounds of similar square were outlined: in Kronotsky Bay, in the northern part of Avachinsky Gulf and near Southeast Kamchatka. Data about species composition of marine fish in the catches in the whole area of the research, about average density of aggregations, distribution, stock abundance and biomass of major commercial fish species on the standard grounds are demonstrated by years of the research. Length-age composition and number by age groups is demonstrated for Alaska pollock and Northern rock sole. Using the results is planned as indexes in adjusting model calculations.

Comparative analysis was carried out for species composition of the catches from major types of fishing gears near the west coast of Kamchatka (in the Kamchatka-Kuril and West-Kamchatka subzones) based on the data of the sectoral fisheries monitoring system (OSM) of the Federal Agency for Fishery and the research data from fishing vessels for 2003–2017. The major fishing gears analyzed were midwater trawls (75.5%), Danish seins (19.1%) and bottom longlines (2.3%). The data available were analyzed in view of possible perspective of changing the target fishery permits into the multispecies permits for aquatic biological resources. An optimal block of species was suggested for each of the major gears. For instance, in the first stage of forming a complex (multispecies) permit for the midwater trawl fishing in the West Kamchatka subzone it is enought to include only two species – pollock and herring into the pool in the approximate ratio 50 ± 5% and 50 ± 5%, as for the Kamchatka-Kuril subzone – one walleye pollock is recommended. The part of the other species fits the terms of 2% by-catch allowed by the “Fishery Rules…”, 2014. Based on the averaged percantage of the main commercial species in catches according to the OSM and scientific observation data, the block of species for the Danish seine fishing permits should include: pollock – 48%, flounders – 24%, cod – 13%, saffron cod – 10% and sculpins – 5%. The volume of other species amswers the terms of 2% by-catch allowed. The optimal fishing gear now to applicate the principle of the blocked quotas is the bottom longline. The block in the fishing permit can vary depending on the target species. In the target fishing of Pacific cod the block can be like this: cod – 78%, halibut – 13%, stingrays – 4%, grenadiers and sculpins – 3 and 1% respectively. In the target talibut fishing the block in the permit can look like: halibut – 88%, grenadiers – 6%, stingrays – 4%, rockfish – 1%. Analysis of specifics of forming the blocks for the permits, including the target species, was provided for all gears considered.

Results of the research allow to figure out modern boundaries of forming general commercial aggregations of the species in visinity of spawning rivers and in the shelf zone of West Kamchatka. It is demonstrated the dynamics of the regional commercial catches and evaluated stock of toothed smelt for the period of the historical highest stock abundance in the second decade of the ХХI century. The data obtained allow to think of a united system of forming toothed smelt commercial stock on the west coast of Kamchatka, although there are obvious centers of reproduction in the rivers of the West Kamchatka subzone (the Rivers Moroshechnaya, Khairyuzova, Belogolovaya and Kovran) and in the Kamchatka Kurile subzone (the Rivers Bolshaya, Opala and Golygina). Redistribution of stock at the level of particular “local stocks” takes place during the autumn and winter feeding of the fish in the shelf zone of West Kamchatka.

Based on some assumptions about growth of north shrimp we made an attempt in this research to evaluate age composition of the crustacean from size structure using the method of mixture separation. Average length, average weight and part of individuals of commercial size were evaluated in different age groups. Obtained results were used to simulate dynamics and consequent likelihood forecast of the commercial stock and total allowed catch of north shrimp near South-Western coast of Kamchatka. Shaefer production model, statistical cohort model and model of the “CSA”-type functional groups dynamics were used for the stock abundance assessment.

Analysis of the fishery of blue king crab is provided based on collected data. State of blue king crab stock abundance in the West-Kamchatka subzone is evaluated. Character of seasonal distribution of commercial males is analyzed, and plots of the maximum dense aggregations of the crab and periods of the most efficient fishing are figured out. The data obtained in the course of commercial fishery monitoring are used for the quality analysis of the catch composition and evaluation of the CPUE. Size-frequevcy distribution of blue king crab males is analyzed comparing to the data pools of previous years.

Analysis of field and laboratory identifications stages of gonad maturity was carried out for 1960–2017. The dynamics of the gonad size and weight and of the gonad-somatic index during maturation were studied. The size structure and the condition of herring oocytes in the ovaries of different stages of maturity was figured out. Seasonal maturation was considered.

Species composition of ichthyoplankton community was analyzed, relative abundance of eggs and fish larvae and seasonal changes in the qualitative composition of ichtyoplankton catches was estimated based on the data of the complex researches in Avachinskaya Bay in 2014–2017. In general 25 species from 11 famelies were found for the whole period of researches in the waters of Avachinskaya Bay. The eggs and the larvae revealed in our catches represented the families, including Pleuronectidae, Gadidae, Cottidae, Ammodytidae, Agonidae, Hexagrammidae, Liparidae, Osmeridae, Ptilichthyidae, Stichaeidae and Scorpaenidae. The ichthyoplankton in Avachinskaya Bay consisted in 92% of eggs and in 8% of larvae. The ichthyoplankton complex was the most reach and abundant in April and May.

Data on the size-age structure, maturation, sex ratio, linear and weight growth of pike of Talovskoye Lake are represented. The data and literature information allow to make the conclusion that the population of northern pike of the Talovka River basin (including the lake itself) stays at a stable lavel for a long period.

The article is made on the field data, obtained by authors in summer of 2018, and archive and literature data.It has demonstrated spatial-temporal dynamics of the level, salinity and temperature of the estuary waters. Issues of transformation of the tidal fluctuations of the water level, of the structure and dynamics of the water mixing zone, of the water dynamics, exchange and warming within estuaries are discussed. Data about spatial characteristics of water mixing zone in the coastal part of the Sea of Okhotsk near the mouth of Krutogorova River are provided. Morphodynamics of bars separating the estuaries of the rivers Icha and Krutogorova from the sea and the effects of the process in the hydrological regime of both estuaries are described. The in-fact data in the article can be used to compare the objects examined to the other estuaries.

Structure and biomass dynamics of demersal community in the Pacific waters off the Northern Kuril Islands were analyzed on the data of trawling surveys for 1987–2015. It is demonstrated that in the aspect of a longterm average the demersal communities are represented mainly by abundant species of gadids (Gadidae), greenlings (Hexagrammidae), sculpins (Cottidae), rockfishes (Sebastidae), snailfishes (Liparidae) and flatfishes (Pleuronectidae). Similar trends of the long-term dynamics of fish biomass are observed in the waters of the Northern and Southern Kuriles, East Sakhalin and West Kamchatka. The long-term data indicate of an increase of the abundance of the stocks in the middle of the 1980th, a decrease in the first half of the 2000th, a new increase in the last half of the 2000th, causing the peak level of the stocks in 2007–2009. Indications of a next decline in the biomass of the stocks have been observed since 2010. The lont-term dynamics of the average density of the fish demonstrated similar trends, although the main trend in 2013–2015 was up.

Effects of copper in concentrations 10, 25 and 50 mkg/L on the population growth, content of photosynthetic pigments (chlorophyll-а and carotenoids) and level of the DNA damage of the microalgae Heterosigma akashiwo were analyzed. The number of cells was similar to control in all concentrations of copper, the content of the photosynhetic pigments decreased and the persent of the DNA damages increased along increasing concentration of the pollutant.