This article introduces bilateral agreements on the joint development of resources on the continental shelf in disputed waters by shelving boundary delimitation, with a particular focus on the Japan-Korea Southern Continental Shelf Agreement. It discusses these agreements' trends, issues, and achievements while underlining their importance in conflict prevention and resource management. As the Japan-Korea Southern Continental Shelf Agreement is scheduled to expire in 2028, this paper considers options for the Japanese government (termination or continuation of the agreement).

The Japan Sea has a unique deep circulation similar to the general circulation of the open ocean, which is said to be one of the factors behind its abundant fishery resources. In recent years, it has been pointed out that this deep circulation may be stagnating due to global warming. By measuring the circulation velocity of deep seawater, a research group from the National Institute for Environmental Studies (NIES) and the Research Institute for Applied Mechanics, Kyushu University, has found that the flow rate is more than 30% slower than in the 1990s.

There are concerns that various developments in Japan's coastal areas have resulted in the deterioration of biological habitats and a decline in fisheries resource productivity due to the reduction of seaweed beds and tidal flats, which are considered to have high biological productivity. Various technologies are being provided to sea areas to improve the productivity of biological resources, with artificial reefs being the central structure among these measures. This paper introduces examples of artificial reefs that make it possible to control the natural energy of tidal currents, and that also have the functions of protecting and nurturing fish juveniles and creating seaweed beds.