TNFRI is responsible to marine research in the northwestern Pacific Ocean east of the Tohoku district. This area is bounded by the Oyashio current in the north and the meandering Kuroshio Extension in the south, and the Tsugaru warm current flows south along the coast. The sea area between the Oyashio and the Kuroshio Extension is called "the Mixed Water Region", since cold eddies extended from the Oyashio and warm eddies such as warm streamer and warm core rings extend from the Kuroshio Extension distribute intricately in this region. The Mixed Water Region and its coastal region are outstanding fishing grounds of many pelagic fishes such as saury, sardine, skipjack and tuna which migrate through the Mixed Water Region and groundfishes such as cod and flatfishes. Mariculture of coho salmon, shellfish, oyster and other species are also productive. Mixed Water Region Fisheries Oceanography Division investigates the physical, biological and ecological features of the Mixed Water Region to understand the ecosystem supporting the high productivity of the Mixed Water Region. Therefore this division will contribute to the appropriate management of resources and preservation of the ecosystem which is the foundation of the fisheries. Recently, it has become to be understood that long-term ocean variability, associated with climate change, is linked to the resource variations. The understanding of the relationship between the long-term ocean variability and resource variation is also an important subject for our research
Satellite image of the sea surface temprature distribution of the Mixed Water Region on Sept 13, 1995

Rosette CTD onboard the R/V Wakataka Maru.

Larval and juvenile sardine.

Templeture distribution at 200m depth of the Mixed Water Region and the Oyashio Region in August, 1995.


Euphausia pacifica.

Japanese version is here

The Organization of TNFRI