Response of lower trophic ecosystem in the Japan sea to horizontal nutrient flux change through the Tsushima Strait

The Japan Sea is a semi-closed sea with straits such as the Tsushima Strait (Korea Strait). The nutrient transport through the Tsushima Strait impacts on the ecosystem around the coast of Japan. We analyzed hydrographic data from the Tsushima Straits to reveal interannual variations in the volume transport, nutrient concentration, and nutrient transport. The nutrient transport in the strait has large interannual variations of ±50% of average transport. We developed a coupled ocean circulation and ecosystem model, in which the lateral boundary condition was applied based on our observation data, and investigated the biogeochemical responses in the Japan Sea to the variations in horizontal nutrient flux through the Tsushima Strait.