Enclosed coastal seas are sea areas where water pollution and eutrophication occur easily due to poor exchange of water as the sectional area of the bay entrance is smaller than the maximum sectional area in the bay.
88 sea areas such as the Seto Inland Sea, Tokyo Bay, and Ise Bay in Japan and sea areas such as Chesapeake Bay, Mediterranean Sea, and the Baltic Sea in the world are recognized as enclosed coastal seas.
International EMECS Center is working to provide information on enclosed coastal seas including geographic specifications, environment, nature, culture, history and industry to run an information center called “Clearing house” that provides links to web sites of each enclosed coastal sea where detailed information is available.