scholarly journals Current abundance of spotted seal ( Phoca largha) in Peter the Great Bay (Japan Sea): unstable equilibrium or sustainable growth?

2015 ◽  
Vol 182 (3) ◽  
pp. 48-54
Author(s):  
Aleksey M. Trukhin

Представлена информация о динамике численности популяции ларги, размножающейся в Дальневосточном морском заповеднике (зал. Петра Великого, Японское море). Современный размер ежегодного приплода оценивается в 750 детенышей при общей численности популяции (без учета приплода) - 3,0-3,2 тыс. особей. Результаты учетов свидетельствуют, что на протяжении последних полутора десятилетий численность местной популяции пребывает в состоянии устойчивого роста. Увеличение численности тюленей сопровождается возникновением новых крупных репродуктивных залежек на тех островах архипелага Римского-Корсакова, где полтора десятилетия назад эпизодически размножались единичные тюлени. Тенденция дальнейшего увеличения численности ларги в зал. Петра Великого сохраняется.

Author(s):  
O.L. Smirnova ◽  
◽  
E.A. Bessonova ◽  
T.A. Emelyanova ◽  
◽  
...  

The results of the biostratigraphic study based on the radiolarian analysis of the rhythmically layered terrigenous deposits from the Islands of the Rimsky-Korsakov Archipelago (Peter the Great Bay, Japan Sea) have been presented. These deposits are most similar to the medium-grained turbidites. For the first time the distribution and stratigraphic division of the boundary sediments of the upper Triassic and lower Jurassic separated by a marking layer were substantiated in the research area. On the basis of comparisons with isochronous zonal units of the Pacific and Tethyan areas in the upper Triassic sediments of the studied sections, layers with Globolaxtorum tozeri (upper Rhaetian) were established, and in the lower Jurassic zone Pantanellium tanuense Zone (Hettangian) was traced and layers with Parahsuum simplum (Sinemurian – Pliensbachian) were established.


2018 ◽  
Vol 195 ◽  
pp. 209-218 ◽  
Author(s):  
G. S. Gavrilova

Marine farms in Peter the Great Bay are oriented predominantly to cultivation of bivalve mollusks that causes excessive accumulation of biodeposits in the areas of plantations. To reduce this negative impact on the ecosystem, development of bicultural farms with cultivation of flterfeeders and detritivores is recommended. In the area of mussel (Mytilus trossulus) plantations in the Sukhodol Bay, the sedimentation rate reaches 34.1 g.m–2.day–1, with mean portion of organic carbon in the biodeposits as 20.2 %. Annual biodeposition from 1 hectare of mussel plantations is about 124 t that corresponds to annual consumption of detritus by 1 million of 1-year-old sea cucumberApostichopus japonicus. By the end of the 4-year cycle of cultivation, the sea cucumbers of commercial size consume this amount of biodeposits within a month (60 g of organic carbon per year each). Production of a sea cucumber plantation with 5 million juveniles of sea cucumber settling every year can exceed 700 t in 10 years of operation, if it is mounted within the bicultural marine farm with bivalve cages as additional source of suspended organic matter.


2020 ◽  
Vol 200 ◽  
pp. 141-154
Author(s):  
O. G. Shevchenko ◽  
K. O. Tevs ◽  
V. M. Shulkin

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.


2020 ◽  
Vol 200 ◽  
pp. 3-23
Author(s):  
G. V. Khen

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.


2016 ◽  
Vol 187 (4) ◽  
pp. 160-161
Author(s):  
Vladimir N. Dolganov

Description of the mackerel Scomberomorus niphonius caught in the Vityaz Bay (Peter the Great Bay, Japan Sea) on September 19, 2015.


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