Tohoku National Fisheries Research Institute conducts research on fisheries in the northern Pacific Ocean off the coast of Tohoku district.The area is called the Mixed Water Region where warm current Kuroshio and cold current Oyashio mix and form complex marine structures and subsequently the area has a high fishery productivity. We research the marine characteristics of the Mixed Water Region and mechanisms of resource fluctuations to provide the latest information about fishery resource management and promotion of fishery and aquaculture production.