scholarly journals Gravimetric Studies in the Sea of Japan

2020 ◽  
Author(s):  
Maksim Georgievich Valitov ◽  
Ruslan Grigoryevich Kulinich ◽  
Zoya Nikolaevna Proshkina ◽  
Tatyana Nikolaevna Kolpashchikova
Keyword(s):  
Gravitational Field ◽  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Tatar Strait ◽  
The Earth ◽  
Structural Density ◽  
Mohorovičić Discontinuity ◽  
Density Modeling

AbstractMarine gravimetric studies were carry out in the waters of the Sea of Japan and the Tatar Strait. Maps of the gravitational field of the earth were completed, structural density modeling was executed, the depth of the Mohorovičić discontinuity was determined.

scholarly journals Organochlorine compounds in flounders of genus Hippoglossoides Gottsche, 1835 from the Far Eastern seas of Russia

2020 ◽  
Vol 5 (1) ◽  
pp. 29-42
Author(s):  
M. M. Donets ◽  
V. Yu. Tsygankov ◽  
M. D. Boyarova ◽  
A. N. Gumovsky ◽  
Yu. P. Gumovskaya ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Organochlorine Pesticides ◽  
Sea Of Japan ◽  
Sea Of Okhotsk ◽  
Household Waste ◽  
The Sea Of Japan ◽  
The Sea Of Okhotsk ◽  
Tatar Strait ◽  
Far Eastern ◽  
Far Eastern Seas

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are global superecotoxicants belonging to a group of persistent organic pollutants (POPs). Fish and seafood are an important source of high-grade protein and polyunsaturated fatty acids, especially for residents of coastal areas. Up to 90 % of all pollutants enter the human body through food. Final depot of POPs in environment is marine ecosystems; therefore, POPs can accumulate in various objects of marine fisheries. The paper presents information on the concentrations of OCPs [HCH isomers (α-, β-, γ-), as well as DDT and its metabolites (DDD and DDE)], and polychlorinated biphenyls (PCBs) in muscles of flounders of genus Hippoglossoides Gottsche, 1835 from the Far Eastern seas of Russia (the Sea of Okhotsk, the Tatar Strait, and the Sea of Japan). Lipids were extracted from fish tissue samples with a mixture of hexane and acetone, followed by destruction of fatty components by concentrated sulfuric acid. OCPs and PCBs were separated by column chromatography with polar and non-polar solvents. Xenobiotics were quantified by gas chromatography – mass spectrometry. To assess quality of this methodology, a standard addition method was used. The average reproducibility of analyte concentrations varied 94.6 to 103.7 %, and it indicates reliability of the data obtained as well as effectiveness of methods applied. Average concentrations of ∑DDT, ∑HCH, ∑OCP (∑DDT + ∑HCH), and ∑PCB were: (62 ± 89), (50 ± 52), (100 ± 125), and (92 ± 45) ng·g−1 of lipids in the samples from the eastern part of the Sea of Okhotsk; (20 ± 17), (36 ± 37), (54 ± 41), and (99 ± 43) ng·g−1 of lipids from the southern part of the Sea of Okhotsk; (40 ± 29), (62 ± 36), (102 ± 50), and (1616 ± 1177) ng·g−1 of lipids from the Sea of Japan, respectively. In the samples from the Tatar Strait, the average levels of ∑HCH, ∑OCP, and ∑PCB were (221 ± 182), (224 ± 180), and (455 ± 317) ng·g−1 of lipids, respectively. DDT was detected in three samples. In the flounders from the eastern part of the Sea of Okhotsk, the highest concentrations of DDT and average concentrations of HCH were recorded, which may be due to the location of a “repository” of pesticides on the Kamchatka Peninsula, where OCPs are buried. The entrance of PCBs into the waters of the southern part of the Sea of Okhotsk can be associated both with intensive shipping and effluents from landfills that carry residual amounts of PCBs into the ecosystem. The southern part of the Sea of Okhotsk is the cleanest of the areas studied and is characterized by the lowest content of DDT, HCH, and PCB in organisms. DDT was practically absent in the flounders from the Nevelsky Bay (the Tatar Strait). At the same time, they showed the highest level of HCH, represented only by β-isomer, which indicates a prolonged circulation of the toxicant in the ecosystem. According to the decree of the Government of the Sakhalin Region, on the territory of Sakhalin there are landfills for out-of-use or banned pesticides; storage of them was performed (at the time of the decree entering the force) with violations that could lead to serious environmental pollution. Most likely, they became the source of pollution of the Tatar Strait. Another source of HCH pollution is currents that carry the waters of the Sea of Japan through the Nevelsky Bay into the Sea of Okhotsk. High levels of PCBs in the waters of the bay may result from intensive shipping and possible impact of household waste dumps on the Sakhalin Island. Flounders from the Sea of Japan are characterized by the highest POPs pollution. The entrance of OCPs into the sea may be due to surface runoffs, river flows, storage leaks of pesticides banned for use, and atmospheric transport from Asian countries where the use of some OCPs is still permitted. The determined levels of PCBs are an order of magnitude higher than those in the flounders from the Sea of Okhotsk and the Tatar Strait, which may be due to active shipping in Sea of Japan waters, influence of operating oil and coal ports in the city of Nakhodka, as well as local pollution of the coastal zone (so called wild beaches). Thus, we have studied the accumulation of organochlorine pesticides (HCH and DDT) and polychlorinated biphenyls in the muscles of flounders from the Far Eastern seas of Russia. With the existing global background of POPs formed on the planet, the levels of these compounds in the flounders of the southern part of the Sea of Okhotsk can be taken as background ones. The Sea of Japan is subject to the greatest anthropogenic pressure, and PCB concentrations are significantly higher in this area than in the Far Eastern seas of Russia and in the compared regions of the world as a whole.

scholarly journals Results of oceanological monitoring in the northwestern part of the Sea of Japan 2018

Trudy VNIRO ◽  
2020 ◽  
Vol 180 ◽  
pp. 5-22
Author(s):  
B. S. Djakov
Keyword(s):  
Sea Of Japan ◽  
Thermal Regime ◽  
Subsurface Layer ◽  
Peter The Great Bay ◽  
The Sea Of Japan ◽  
Northwestern Part ◽  
Southern Primorye ◽  
Tatar Strait ◽  
Main Components ◽  
Anticyclonic Eddies

In this work, based on the data on the sea surface temperature, deep-sea oceanographic observations, we studied the thermohaline and dynamic conditions of the Southern Primorye and open waters of the northwestern part of the Sea of Japan in the spring and summer of 2018. The features of the oceanological structure were revealed, and state and water conditions were estimated. Anticyclonic eddies were observed in the open waters of the northwestern part of the Sea of Japan. In the water circulation, its main components are shown, the roles of the Primorsky and West Sakhalin currents are highlighted. The concept of the structure and nature of the Primorsky Current has been expanded. It is shown that in the vertical structure of the waters of Peter the Great Bay (April) and the western part of the Tatar Strait (June) there existed the near-bottom and subsurface cold layers. In the waters of southern Primorye in May, these layers were not observed. Based on the meridional displacement of the vortex structures and the criterion for assessing the thermal regime of the waters of the northwestern part of the Sea of Japan — the average temperature of the subsurface layer 50–200 m — it was established that in the year under study the thermal regime of the sea was classified as warm.

Peculiarities of the distribution of methane concentration and methane fluxes at the water-air interface in the Tatar Strait of the Sea of Japan

2015 ◽  
Vol 40 (6) ◽  
pp. 427-433 ◽  
Author(s):  
G. I. Mishukova ◽  
V. F. Mishukov ◽  
A. I. Obzhirov ◽  
N. L. Pestrikova ◽  
O. F. Vereshchagina
Keyword(s):  
Sea Of Japan ◽  
Methane Concentration ◽  
The Sea Of Japan ◽  
Tatar Strait ◽  
Air Interface ◽  
Methane Fluxes

scholarly journals The integrated geological and geophysical expedition aboard the R/V Akademik Oparin to the Tatar Strait, Sea of Japan (cruise No. 54, 2017)

2019 ◽  
Vol 59 (2) ◽  
pp. 311-314
Author(s):  
M. G. Valitov ◽  
R. B. Shakirov ◽  
A. V. Yatsuk ◽  
K. I. Aksentov ◽  
Z. N. Proshkina ◽  
...  
Keyword(s):  
Sea Of Japan ◽  
Anthropogenic Impacts ◽  
World Ocean ◽  
Fluid Flows ◽  
Geological Structure ◽  
The Sea Of Japan ◽  
Tatar Strait ◽  
Research Cycle ◽  
Academy Of Sciences ◽  
Far Eastern

According to the Plan of Integrated Scientific Research of the World Ocean for 2017–2022, the Il’ichev Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences (POI FEB RAS) began a comprehensive study of the northern part of the Sea of Japan and the Tatar Strait, having developed a three-year plan for expeditionary research in the area. The first expedition from the three-year expeditionary research cycle was carried out from September 21 to October 31, 2017 on the R/V “Akademik Oparin” (cruise № 54). The main goal of the expedition was to study the geological structure, conditions and mechanisms for the formation of the Tatar Strait, to study the correlation of the distribution of gas-fluid flows with a network of tectonic disturbances of different ranks in one of the seismic areas of Sakhalin Island, as well as the reaction of the Sea of Japan to climate change and increasing anthropogenic impacts.

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