There are over 1,700 marine protected areas (MPAs) in the United States established by federal, state, and territorial governments. These areas cover 41 percent of U.S. marine waters and vary widely in their purpose, legal authorities, managing agencies, and level of protection. MPAs that are focused on the protection of ecosystem, biodiversity, and cultural resources cover about eight percent of marine waters.
Although MPAs are found in every region of the United States, the West Coast, including California, Oregon, and Washington, has the highest number of MPAs. However, the region with the largest area of MPAs is the Pacific Islands. This is because of the designation of the Papahānaumokuākea Marine National Monument, which is one of the largest marine conservation areas in the world.