In the Seto Inland Sea, a complex waterway consisting of 12 bays, open seas, straits and channels, the characteristics of the environment vary dramatically from one region of the sea to the next. While it is common to think of the Seto Inland Sea as a single entity, the prefectures adjoining this sea need to form a coherent system of governance for the joint management of each sea area. This governance requires not just the collaboration of industry, government and academia, but also the concerted efforts of nearby residence. This new framework will open up an unprecedented new path toward environmental repair and creation.

A great volume of sea sand has been gathered from the Inland Sea for use in construction aggregates and landfill. Because this activity is severely damaging to marine resources and the natural environment, a movement has emerged to prohibit the gathering of sea gravel. Unfortunately, in many areas the damage is so great that the environment can never be restored to its original state, and in some prefectures resistance to such a ban is strong. The environmental problems of the Seto Inland Sea still require delicate handling.

The western gray whale is a species in grave danger of extinction. Found only in Asian waters, is thought to have dwindled to a single population of no more than 100 individuals. Their migratory route traces around the island of Sakhalin, where oilfield development is beginning on the continental shelf. Observers are concerned for the impact any resulting environmental change may have on the western gray whale. Although the Sakhalin Energy Investment Company Ltd. involved in the development project claim their activities will not affect the environment, no guarantees are on offer.