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Offshore Surface 419 Sea of Okhotsk vicinity

Note; The offshore surface areas have many physically fluid factors such as ocean current or seasonal changes, which may effect on the spawning grounds or distribution areas of certain organisms. Therefore, it is difficult to fix certain area as EBSAs of offshore surface spatially. In addition, available data for analysis are very limited. Therefore, the EBSAs of offshore surface shows the probabilistic distribution of important area as a result of mechanical analysis using best available data at the time, so that there are problems such as that some places considered to be consecutive from the ecological features are divided. Further analysis will be required to improve when the data became available in the future, and it is necessary to review the analysis method.

Basic Information A separate window opensReferences

Area (km2) 18085

Reason(s) for selection A separate window opensCriteria

Selected due to high levels on the criteria 5, 8. And selected by the MARXAN software.

Characteristics A separate window opensReferences

These waters are the lowest-latitude waters in the world where seasonal sea ice forms, and the only icy waters in Japan. The cold East Sakhalin Current flows south along the east coast of Sakhalin. The Soya Warm Current, coming from the Tsushima Current, flows in through the La PĂ©rouse Strait, flowing as far as the vicinity of the Shiretoko Peninsula along Hokkaido's Sea of Okhotsk coast. When seasonal sea ice forms in the northern Sea of Okhotsk during winter, low-temperature, high-salinity sea water rich in nutrients sinks, forming the cold intermediate layer of the Sea of Okhotsk. This cold intermediate layer spreads in the intermediate later from the Sea of Okhotsk to the northwestern North Pacific as a mass of nutrient-rich water, supporting abundant biological production beginning with the massive proliferation of phytoplankton in the spring. Ice algae grow thickly on the bottom surfaces of seasonal sea ice, and when they sink they serve as feed for creatures living on the sea floor (mainly filter feeders). Like the waters of the Oyashio Current, krill, copepods and other large zooplankton are abundant here, and these serve as feeding waters for cod, flounder, crab, and other useful sea creatures that feed on these, as well as sea birds, pinnipeds, and cetaceans. While from winter to spring these waters are dominated by cold-water marine organisms resembling those of the ice edge ecosystems of the polar regions (cod and other bottom fish, sea eagles, and pinnipeds that breed on the ice surface), from summer to fall, migratory fish from the surface layers of warm currents migrate here.

Species information (*) A separate window opensData source

Criteria 2
Laemonema longipes (Threadfin hakeling) [Sp]
Sebastes schlegelii (Korean rockfish) [Sp]
Theragra chalcogramma (Alaska pollock) [Sp]
Clupea pallasii (Pacific herring) [Sp]
Gadus macrocephalus (Pacific cod) [Sp]

* This is the species list of which meet the criteria. In that matter, this list does not include all species that inhabit the individual area.
Abbreviation in the information is as follows.
[Br/Ne] : Adjacent water of breeding area or nesting site
[Sp] : Spawning area


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