scholarly journals Comparison of the Far-Eastern Seas and North-West Pacific by integral characteristics of pelagic and benthic trawled macrofaun

2014 ◽  
Vol 178 (3) ◽  
pp. 58-67
Author(s):  
Igor V. Volvenko
Keyword(s):  
Bering Sea ◽  
Large Scale ◽  
North West ◽  
The Pacific ◽  
Integral Characteristics ◽  
The Pacific Ocean ◽  
Far Eastern ◽  
Far Eastern Seas ◽  
The Bering Sea

The Bering Sea, ​​Okhotsk Sea, Japan/East Sea and adjacent waters of the Pacific Ocean (mainly within EEZ of Russia) are compared by abundance of pelagic and benthic macrofauna, its species richness, evenness, diversity, and mean weight of animals using the data of long-term large-scale pelagic and bottom trawl surveys conducted by Pacific Fish. Res. Center (TINRO) in 1977-2010.

scholarly journals 137Cs concentration in surface waters of Far Eastern seas: Results of expeditionary research in 2018

2020 ◽  
Vol 5 (3) ◽  
pp. 55-63
Author(s):  
O. N. Miroshnichenko ◽  
A. A. Paraskiv
Keyword(s):  
Sea Of Japan ◽  
Surface Waters ◽  
Bering Sea ◽  
Sea Of Okhotsk ◽  
The Sea Of Japan ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Far Eastern ◽  
Far Eastern Seas ◽  
The Bering Sea

Based on the results of expeditionary research carried out during the 82nd cruise of the RV “Akademik M. A. Lavrentyev” (01.06.2018–20.07.2018), the assessment of current levels of concentration activity of technogenic radionuclide 137Cs in surface waters of Far Eastern seas is given. The studies were carried out in the northwestern part of the Sea of Japan, the southern part of the Sea of Okhotsk, the coastal waters of the Pacific Ocean near the Kamchatka Peninsula, and the western part of the Bering Sea. Activity of 137Cs in seawater samples was determined by sorption method using two series-connected adsorbers with subsequent measurement of 137Cs content via its gamma-emitting daughter radionuclide 137mBa. Sorption efficiency was assessed by the difference in activity on the first and second adsorbers. A comparative analysis of contamination levels of water areas studied was made. It was revealed that 137Cs volumetric activity in surface water of the Sea of Japan varied from (2.9 ± 0.1) to (5.1 ± 0.3) Bq·m−3, in the Sea of Okhotsk – from (1.8 ± 0.1) to (2.3 ± 0.1) Bq·m−3, and in the Bering Sea – from (1.7 ± 0.1) to (3.1 ± 0.1) Bq·m−3. The maximum 137Cs concentrations were registered in the Sea of Japan, which might be due to its isolation from other water areas and presence of secondary sources of radionuclide intake. In general, contamination of adjacent water areas is insignificant, and fluctuations in concentrations occur within technogenic isotopes global background in the marginal seas of the Pacific Ocean.

scholarly journals Feeding of smoothtongue Leuroglossus schmidti in the Bering, Okhotsk Seas and adjacent waters of the Pacific Ocean

2016 ◽  
Vol 184 (1) ◽  
pp. 150-157
Author(s):  
Alexander Ya. Efimkin
Keyword(s):  
Bering Sea ◽  
Mesopelagic Fish ◽  
The North ◽  
Important Prey ◽  
The Pacific ◽  
Upper Epipelagic Layer ◽  
The Pacific Ocean ◽  
The North Pacific ◽  
Epipelagic Layer ◽  
The Bering Sea

Smoothtongue Leuroglossus schmidti is a small mesopelagic fish species common for subarctic waters. It rises to the upper epipelagic layer at night for feeding and preys mainly on euphausiids, copepods and amphipods. Its mean index of stomach fullness reaches 68 ‱ in the epipelagic layer, but it almost doesn’t feed deeper than 200 m, judging by a little food in the stomach. In the Bering Sea, euphausiids dominate in its diet and the portion of copepods is small. In the ​​Okhotsk Sea, each of these two groups provides a half of the diet. In the North Pacific, the portion of copepods is 63 % on average, euphausiids are the second important prey, and amphipods occur in the diet occasionally. Daily ration of smoothtongue is about 1.4 %.

scholarly journals Transformation of baroclinic tidal waves in the conditions of the shelf of the Far Eastern seas

2021 ◽  
Vol 946 (1) ◽  
pp. 012024
Author(s):  
P D Kuznetsov ◽  
E A Rouvinskaya ◽  
O E Kurkina ◽  
A A Kurkin
Keyword(s):  
Bering Sea ◽  
Sea Of Okhotsk ◽  
Sand Dunes ◽  
Winter Season ◽  
Published Data ◽  
The Sea Of Okhotsk ◽  
Tidal Waves ◽  
Far Eastern ◽  
Far Eastern Seas ◽  
The Bering Sea

Abstract This work is devoted to the study of the regimes of transformation of baroclinic tidal waves under the conditions of the Far Eastern seas within the framework of a fully nonlinear numerical model. Two sections were selected to study the features of wave dynamics – in the Sea of Okhotsk (Sakhalin Island shelf) and in the Bering Sea (near Cape Navarin). On the basis of the performed calculations, regional and seasonal features of the transformation of baroclinic waves and the structure of the flow induced by them were revealed. It is shown that the dynamics in the winter season is less intensive. The rotation effect on the formation of solibore in the studied conditions is analyzed. The obtained estimates of wave amplitudes and velocities are consistent with the published data of field observations in the Sea of Okhotsk. For the Bering Sea, the conditions are shown to be favorable for the generation of intensive internal waves, which indirectly confirms the hypothesis of influence of such waves on the formation of underwater sand dunes.

scholarly journals Feeding of adult sea bream Brama japonica in the Pacific Ocean and the Bering Sea

2014 ◽  
Vol 176 (1) ◽  
pp. 210-215
Author(s):  
Alexander Ya. Efimkin
Keyword(s):  
Bering Sea ◽  
Feeding Habits ◽  
Sea Bream ◽  
Daily Ration ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
High Concentrations ◽  
The North Pacific ◽  
The Bering Sea

Feeding habits of adult sea bream are considered on the samples collected in the North Pacific and Bering Sea in the last several years. This species is a predator with the diet highly dependent on its habitat and composition of prey (small-sized fish and squids). It has two or three peaks of consumption daily, which change seasonally and year-to-year; anyway, the morning (3-6 a.m.) is usually the time of the lowest consumption, at least in summer and autumn, and the daytime is the normal time for feeding. The sea bream does not eat zooplankton usually, but Euphausia pacifica was a significant portion of its diet (34 %) in the southern part of surveyed area in the summer of 2009, possibly because of high concentrations of euphausiids in that area. Daily ration of adult sea bream is 2.5-3.5 % of its body weight.

scholarly journals Some aspects of biogeography with reference to zoning of the Far- Eastern Seas of Russia and adjacent waters of the Pacific Ocean

2015 ◽  
Vol 183 (4) ◽  
pp. 3-26
Author(s):  
Oleg A. Ivanov ◽  
Vitaly V. Sukhanov
Keyword(s):  
Climatic Factors ◽  
Japan Sea ◽  
Pacific Waters ◽  
The Pacific ◽  
History Of ◽  
The Pacific Ocean ◽  
Far Eastern ◽  
Far Eastern Seas ◽  
Latitudinal Zoning ◽  
Epipelagic Layer

Formation of biogeography, its methodological features, and its status as interdisciplinary science combining biological and geographical aspects are discussed. There is noted that the descriptive period of biogeography has passed, and now any «manifestation of life on the globe» requires its explanation. These explanations are reduced to three non-adversarial restrictions: environmental (ecology), temporal (history of origin, evolution), and spatial (geography). General regularities of life distribution over the Earth surface are analyzed, in particular the features of pelagic organisms habitat, and the concept of «dynamic biogeography» is discussed. Latitudinal zoning of epi- and mesopelagic layers in the Far-Eastern Seas of Russia and adjacent Pacific waters is proposed on the basis of data about areas and distribution of 493 species of nekton (fishes and squids) for the 30-year period (1980-2009) obtained from 27 thousand trawl samples caught in 272 expeditions. This zoning uses a new approach related to the chorological direction in marine biogeography realized with the index of latitudinal zoning (ILZ). For this index calculation, all types of species areas (formerly expressed in verbal forms) were identified with numerical codes, which were averaged for all species in each sample, then the regions with certain ILZ values and borders between them were determined on the maps of ILZ distribution, and latitudinal zones and subzones were defined. There is found that the epipelagic layer of the Okhotsk and Bering Seas corresponds to the high-boreal latitudinal subzone and the epipelagic layer of the northwestern Japan Sea and the major part of Russian EEZ in the Pacific corresponds to the low-boreal latitudinal subzone. Fauna of nekton in the mesopelagic layer of all studied regions corresponds by its chorological structure to the low-boreal latitudinal subzone. So, zoning of epipelagic and mezopelagic layers is significantly different, with the fragmentation reducing with depth, possibly due to weakening of climatic factors influence. The biogeographical zoning is not literally zonal but corresponds to structure of the environments (water masses, fronts, currents, gyres, eddies, etc.).

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