Ecosystem of Far-Eastern Seas

The Far-Easernt Fishery Basin includes Sea of Okhotsk, West Bering Sea, and Sea of Japan. There areas have a great concentration of wild life. Ecosystems of West Bering and Okhotsk seas are considered as the most productive marine areas around the world.

TINRO have conducted regular ecosystem surveys since the 1980s. The objectives of these surveys were typically broad including physical and chemical data collection, biomass estimates, and species identification. These surveys have been conducted over a period of 20 years (some 60 surveys conducted seasonally) providing a historical baseline of the main ecosystem characteristics, e.g. composition and biomass of nekton, bottom fish, macro-benthos, and meso- and macro-plankton. According to TINRO, the Far-Eastern Seas ecosystem components of secondary and higher trophic levels are estimated as follows:     
  • Zooplankton - 1000 mln tons;
  • Zoobenthos - 500 mln tons;
  • Phytobenthos - 25 mln tons;
  • Nekton - 80 mln tons;
  • Demersal fish - 80 mln tons;
  • Seabirds - 50 mln species;
  • Seals - 3-5 mln species;
  • Dolphins - 300-500 thous species;
  • Whales - 50-100 thous species.
Sea of Okhotsk is an area for 435 different fish species, West Bering Sea – for 318 species. Within the epipelagic fish communities, Walleye pollock plays a central ecological role in the Far East seas. These studies underscore the dominant role played by pollock in the ecosystems in which they are found. Although pollock are major consumers, they are also food for a number of predators, including pollock (cannibalism), other fishes, and marine mammals (mainly Steller sea lion and northern fur seals). During the 1980s, predators accounted for an estimated 58-78% of the annual losses of Alaska pollock, whereas the fishery accounts for about 22-42%.There are many researches to understand an impact of the removal of pollock from the Far East seas system. Models of pelagic communities have also been constructed to investigate temporal changes in structure and function, but these have not yet been published. Another approach to assessing the impact of pollock in the ecosystem has been to estimate the size and composition of the consumption of pollock. 

In 2014-2015, PCA have commissioned a specific  survey of mid-water trawl pollock fishery on the Sea of Okhotsk ecosystem and trophic structure. It concluded that there  is  no  negative  impact  on  the  ecosystem. The current level of Walleye pollock removals is absolutely safe for the ecosystem of the Sea of Okhotsk. 

References:
Marine Ecosystem of the Sea of Okhotsk 2003-2008. PICES Special Publication 4.

Ecosystem-based principles in the contemporary fisheries management on the Russian Far East. Presentation by V. Radchenko at PICES session.

Large marine ecosystems of Russia's: West Bering Sea / Matishov, Balykin, Karpenko. 2009.

Results of monitoring and ecosystem research of biological resources of the Far East seas of Russia. Shuntov, Bocharov, Dulepova, Volkov, Temnykh, Volvenko, Melnikov, Nadtochy. 2003.

Characterization of the Sea of Okhotsk ecosystem based on ecosystem modeling. V. Radchenko. 2015.

Okhotsk Sea ecosystem overview. Presentation by V. Lapko at PICES session. 

Simulation model of Okhotsk Sea ecosystem. Krapivin. 2004.

Dynamics and bioproductivity of the Russian Far East seas ecosystems due to modern antropogenic activites and global climate changes. Report by Far East Branch of Russian Academy of Science. 2012.

Walleye Pollock in the Far East Seas ecosystem. Shuntov, Volkov, Yemnykh, Dulepova. 1993.

Status and objectives of ecosystem studies of biological resources in Russian Far-Eastern seas. Bocharov, Shuntov. 2004.   
   
Species diversity of the North-West Pacific pelagic macrofauna. Volvenko. 2007.

Biota and bioresources in the marine macroecosystems of the Far Eastern economic zone of Russia. V. Shuntov. 2009.

Composition and present status of epipelagic communities in the Sea of Okhotsk. Shuntov, Volkov, etc. 1990.