Summarized results from ecosystem marine surveys in the Barents sea and adjacent water areas by Knipovich Polar Research Institute of Marine Fisheries and Oceanography (PINRO) as well as the available information on hydrometeorological conditions and Russian fishing activity in the area of the Northern Fishery Basin in 2017 are presented. The analysis of temporal and spatial changes in oceanographic conditions happened in the Barents and Norwegian seas and fishing areas of the North Atlantic due to the influence of multi-scale processes in the atmosphere and ocean was made. The results from the analysis of the effect of peculiar hydrographic conditions on distribution and migrations of commercial fish species in the Barents and Norwegian Seas and to the west of the British Isles are given. Researches carried out in 2017 showed that the thermal state of the waters in the North European Basin as a whole remained at the level of warm and anomalously warm years. The heat content of water in the area west of the British Isles has significantly increased compared to the previous years. The absence of significant changes in environmental conditions in the Irminger Sea and most areas of the North-West Atlantic is noted. 

The paper presents an overview of the meteorological (air temperature, wind) and oceanographic (water temperature and salinity, areas of water masses, ice coverage) conditions of the Barents Sea in 2017. The overview was prepared on the basis of data obtained during surveys in the Barents Sea by PINRO. As well as other available information on hydrometeorological conditions in the Barents Sea and adjacent area was used. The analysis of spatial and temporal changes in the meteorological and oceanographic conditions has showed that the air and water temperature in the Barents Sea in 2017 remained at the high level of warm and anomalously warm years. The salinity of the sea waters, at the same time, was close to the long-term mean. The area of the Barents Sea occupied by the Atlantic waters remained, still, quite large, although it decreased compared to 2016. The area occupied by the Arctic waters remained small in 2017, although, unlike the Atlantic waters, it increased relative to the previous year. The total ice extent of the Barents Sea in 2017 remained much less than the average. 

The results of research work conducted by the saury fishery vessel “NIKA 101” in the open waters of the North-West Pacific (NWP) and the South Kurile region during September- November 2014–2016 are presented. The distribution and migration routes of saury in the North- West pacific in 2014–2016 are shown. In 2014 and 2015, the main migrations of a large saury traditionally took place along the Kuril Islands along the Oyashio front and further south along the periphery of the South Kurile Eddy. The smaller and medium-sized saury migrated outside the Russian EEZ along the Northern Subarctic Front. The distribution and migration routes of the saury in the NWP in 2016 significantly differed from the distribution pattern in 2014 and 2015 In September-October 2016, the saury fishery was mainly conducted in the frontal zones of the oceanic and subarctic fronts where the surface temperature of water was 15–17 °C, unlike in previous years when saury basically occurred in waters with a temperature of 12–14 °C or less. 

The global climatic system is characterized by existence of the so-called teleconnections which represent statistically significant synchronous correlations in the remote areas of Earth. In the paper, a review and detailed description of the main teleconnection patterns (TP) in the atmosphere and in the ocean is given. It has been shown that the climatic regime shift in the second half of the 1980s accompanied by strengthening of the North Atlantic Oscillation and eastward displacement of its centers resulted in essential changes in position and intensity of the centers of other teleconnection patterns in North Atlantic, Eurasian and West Pacific sectors and also in the character of their impact on surface water layer in the North Atlantic and North Pacific. The teleconnections in the atmosphere and ocean have significant effects on the long-term changes in recruitment and survival conditions of various target species. The close connection between survival conditions of walleye pollock in the northern Okhotsk Sea and intensity of the Subarctic gyre, which, in turn, depends on phase of the North Pacific Oscillation/North Pacific Gyre Oscillation was revealed. At the same time, changes in abundance of recruitment of East Kamchatka walleye pollock are opposite to changes in the mean winter index of the Arctic Oscillation. Thus, the idea of teleconnections in the “atmosphere-ocean” system, the retrospective analysis of the related climatic regimes and prediction of the expected climate changes in one or another region based on this analysis may become a reliable basis for the medium- and long-range forecasting of tendencies of changes in many target species stocks of the Russian fishery. 

Analysis of oceanological conditions in the Japan Sea was carried out by satellite and ship information in May-June 2000–2017. Satellite data is represented by the sea surface images in the infrared and optical bands, and the ship information is represented by deep-sea measurements of temperature and salinity at standard oceanographic cross sections. According to altimetric data, maps of the sea level anomalies were constructed with the aim to identify geostrophic circulation in the springs of the years under study. The joint use of satellite and oceanographic information allowed to execute a three-dimensional analysis of oceanological structures (currents, fronts and their sections, anticyclones and water masses). As a result of this work, the typification of the spring seasons 2000–2017 to three groups — the water thermodynamics, the position of oceanographic structures on satellite maps and on the oceanographic sections was performed. The dominant feature of typification is the water thermal state. It is shown that the water temperature fluctuations can influence the survival rate of walleye pollock in the early stages of ontogeny and the formation of annual classes abundance only indirectly, primarily through biota. 

The Pacific saury Cololabis saira is among the most abundant pelagic fish species in the North Pacific. During 1950–2016 the dynamics of its catch and catch per unit effort (CPUE) has been characterized by the well-expressed quasi-decadal variability associated with the large-scale climatic processes in the North Pacific region. There was a quite good opposite relationship (r = –0.45; p = 0.03) between time series of CPUE and mean winter (January-April) index of the North Pacific Gyre Oscillation (NPGO) at zero lag. The analysis revealed also a close relationship (r = 0.68; p = 0.0009) between CPUE and winter NPGO index for 1994–2016 when the time series of the index was shifted by 5 years ahead relative to the CPUE time series. Catch per unit effort increased with warming of surface water east and northeast of Japan. The 5-year time lag was obviously associated with westward propagation of Rossby waves generated by the North Pacific Oscillation/NPGO system in the eastern and central North Pacific, which reached its western boundary and modulated decadal variations in the Kuroshio-Oyashio Current system. At the same time, saury catches in 1950–1993 did not reveal statistically significant relationship with the NPGO index at time lags from 0 to 5 years. Further research of climate impact on abundance dynamics of Pacific saury are needed, using additional biological, fishery and climatic data. It will allow for developing forecasts of saury stock state, with account of the large-scale climatic processes in the North Pacific. 

Water mass and some species of commercial fish distribution in north-western part of the Bering Sea and western part of the Chukchi Sea in 2003, 2007, 2008, and 2010 were studied. Pelagic and benthic fish concentrations are reviewed in comparison with corresponding water layers. Six water masses were distinguished in total. Four of them were observed both in the Bering Sea and in the Chukchi Sea; the remaining two water masses are formed in each sea separately. Bering Sea coastal water mass (BCW) predominates in the surface layer. Desalinated water mass of gulf origin (DGW) is being formed in the inner parts of the Gulf of Anadyr and Norton Sound. Siberian coastal water mass (SCW) is found along Siberian coast of the Arctic Ocean. Bering Sea summer water mass (BSW) is observed along the western shore of the Chirikov Basin. Bottom layer BCW is found off the coast of Alaska only, and BSW predominates in other areas of the Bering Sea and the Chukchi Sea. Small areas of the seas are occupied by Pacific winter water (PWW) and recently ventilated winter water (WW) with a temperature close to the freezing point. Main fish concentrations were found in the Gulf of Anadyr in BCW area (salmons in the surface layer) and in BSW (cod, Pollock, and herring in the bottom layer). In the Chukchi Sea, only few individuals of mature Chum salmon were caught in BCW and SCW areas, and one individual of red salmon and three individuals of Chinook were caught in BCW area. 

The Barents Sea, being a transition area between the North Atlantic and the Arctic Basin, plays a key role in water exchange between them. Atlantic waters enter the Arctic Basin through the Barents Sea and the Fram Strait. Variations in volume flux, temperature and salinity of Atlantic waters affect hydrographic conditions in both the Barents Sea and the Arctic Ocean and are related to large-scale atmospheric pressure systems. In this paper, meteorological and oceanographic conditions of the Barents Sea were analyzed over the last half century. An attempt was made to formulate integral indices for characterizing the thermohaline conditions of the Barents Sea as a whole. Using them, since 1965, large periods with different thermal (warm/cold) and haline (fresh/saline) conditions were found. A stable warm period in the Barents Sea has been observed since 2000. Since 2005, the sea waters have been the warmest and the most saline for the entire considered period. The year of 2016 was characterized as a record warm in the sea as a whole. 

Species composition, spatial structure, and seasonal and long-term variability of the zooplankton community in the Amur Bay are considered on materials of its two-decade monitoring. Influence of the environments variations on zooplankton is analyzed and the principal aspects of the community functioning are discussed. Two different species groupings of zooplankton are distinguished within the bay, generally in the limits of the pre-estuarine and marine coastal water masses. Small-sized copepods compose the bulk of zooplankton community in both zones, but either Acartia aff.clausi and Oithona brevicornis (in the pre-estuarine waters) or Oithona similis, Pseudocalanus newmani, and Paracalanus parvus (in the marine coastal waters) dominate in dependence on salinity. Nine biological seasons are revealed within the annual cycle of zooplankton succession; species composition and total abundance of the community change crucially with the seasons change. Strong links of interannual variations of zooplankton with thermal or saline conditions are not found, but the portion of allochthonous species fluctuates in direct correlation with the summer monsoon intensity, that is better visible in decadal scale. The deep-water species (Sagitta, large-sized copepods as Neocalanus plumchrus and Calanus glacialis, subtropical species as Calanus pacificus and Paracalanus parvus, and some other species) could be transported into the Amur Bay with the wind-induced water circulation both at the sea surface and at the bottom, in dependence on the species and depth of their aggregations. In climate scale, a tendency to increasing of zooplankton abundance prevails recently due to local species, that is conditioned by separating of high-productive coastal waters from the deep-water sea caused by the cross-shelf exchange weakening with weakening of monsoon winds. 

The article discusses the results of the analysis of 469 chlorophyll a profiles obtained from the buoys of the project Biogeochemical-Argo from May 7, 2015 to May 14, 2018 in the Drake Passage and the open part of the Scotia Sea between 53–65° S, 40–70° W. Profiles led to standard horizons. It was noted that during the period under review it became possible to trace the dynamics of seasonal changes in the concentration of chlorophyll-a in four sublatitudinal zones. In the area under consideration, phytoplankton reached its highest development in December, in the SFZ (Secondary frontal zone) the maximum values reached 4.11 mg / m³, the lowest concentration of chlorophyll-а was observed in August, while the lowest values of the maximum were also observed in the SFZ and were 0.16 mg/m³. According to the dynamics of the variability of the curves of chlorophyll values, the similarity between the SASM (sub-antarctic surface water mass) and SPFZ (South polar frontal zone) zones and between AZ (Antarctic zone) and SFZ is highlighted. In the areas of SASM and SPFZ, the range of values of the chlorophyll-а maximum during the year was less (0.22–3.45 mg/m3) than in the southern regions, the second peak was in May. AZ and SFZ had similar pronounced seasonal differences, the values of chlorophyll content in the maximum zone ranged from 0.09–8.02 mg/m³, the second peak was observed in February. Surface maxima were observed in 33.9% of cases, mainly in the winter period in the area of the SASM. The difference between the surface values and the values in the layer of the maximum in the winter period for all zones was 5–12%, in the summer period in the SASM and AZ reached 48%. As a trend, an increase in the average maximum depth from February (37 m) to October (15.5 m) was observed. 

In the previous study, based on the data on environmental conditions, which had been collected during YugNIRO’s oceanographic surveys in the western half of the Sea of Azov in the summer seasons of 1992–2006, the long-term inter-annual prognostic relationship between solar activity and certain values of near-bottom temperature and oxygen content, characterizing the possibility of an incoming pre-suffocation and suffocation event, was found out. As a follow-up to that research, the areas with various ranges of vertical thermohaline stability, near-bottom temperature and oxygen content have been calculated for the entire sea (excluding the Taganrog Bay), based on the results of the summer oceanographic surveys, carried out by AzNIIRKH in 1989–2016. For each summer season, conditional probabilities of pre-suffocation and suffocation events have been determined; they were calculated as a sum of products of areas of each parameter’s ranges by the conditional coefficients, which corresponded, according to the authors’ expert evaluation, to the degree of proximity of environmental conditions that could induce a fish pre-suffocation and suffocation event. Significant (with the confidence level of more than 99%) correlation of average annual values of solar activity (the Wolf number) and conditional probability of fish pre-suffocation and suffocation event by temperature and thermohaline parameters made it possible to predict this probability with one-year forecast interval. According to a provisional forecast, conditional probability of pre-suffocation and suffocation events for the summer seasons of 2019–2020 exceeds average multi-annual level by around 1.5 times. 

It is shown that the unfavorable conditions of the pink salmon habitat in the estuarine-coastal period of life (reproduction in the rivers of the eastern Sakhalin coast) leads to a decrease in its abundance. An important indicator of the state of such conditions is the SST anomalies in May-June. Extreme cooling in the coastal Sakhalin regions is caused by the abnormal development of regional atmospheric centers of action. The analysis of hydrometeorological conditions was carried out by the methods of interval recognition, taking into account its speed and rather good accuracy. This made it possible to significantly reduce efforts in analyzing the impact of hydrometeorological conditions on the life cycles of the East Sakhalin pink salmon. As a result of application of the method of interval recognition on a complex of hydrometeorological parameters, high recognition coefficients in years of extremely low catches in odd and even years were obtained. Based on the data obtained, may and June are critical months for the temperate zone for the reproduction and formation of the number of pink salmon of Eastern Sakhalin, as well as its redistribution by fishing areas. The regional mechanism of interaction of the atmosphere and ocean in the years of intensive development of the Okhotsk anticyclone, which is characterized by the formation of local anomalies against the background of thermobaric structures over the Central area 2 e. s. r. 

The Kola Section is mainly located in the southern part of the Barents Sea and crosses the Atlantic waters flowing from the Norwegian Sea into the Barents Sea and further into the Arctic Basin. Observations along the section started in May 1900 and it is one of the world’s longest time-series. Unfortunately, in 2016 and 2017, the Kola Section was not occupied during 12 months (from June 2016 to May 2017 inclusive); this unique time-series was interrupted. This paper presents methods and results of restoration of missed data on water temperature in the Kola Section in 2016–2017. The restoration was carried out using: (1) internal structure of data series from the Kola Section, (2) multiple linear regression method and data from other nearby sections, namely: «Fugløya–Bjørnøya» and «Vardø-N», (3) modelled data from the Copernicus website. As a result, data on water temperature in the 0–50, 0–200, 50–200 and 150–200 m layers in the inner (stations 1–3), central (stations 3–7) and outer (stations 8–10) parts of the Kola Section were restored for each month from June 2016 to May 2017.