Skip to main content
U.S. flag

An official website of the United States government

This site is currently in beta, and your feedback is helping shape its ongoing development.

Defacto Marine Protected Areas of the United States

Published by Office of National Marine Sanctuaries | National Oceanic and Atmospheric Administration, Department of Commerce | Metadata Last Checked: December 18, 2025 | Last Modified: 2008-06-01T00:00:00.000+00:00
These data provide the spatial boundaries of DeFacto Marine Protected Areas in U.S. Waters. With nearly 1200 sites (for which GIS data are available), DFMPAs cover 3% of the U.S. waters, (0-200 nautical miles offshore), which includes the Exclusive Economic Zone (EEZ), Territorial Sea, and state waters. DFMPAs range in size from less than one acre to more than 40,000 km2, though the vast majority is at the smaller end of this spectrum. Most of the small sites were created to provide places for vessels to anchor safely. Most of the large sites provide dedicated training and operation areas for various branches of the U.S. military, or facilitate the transfer of oil and gas to moored tanker vessels.

data.gov

An official website of the GSA's Technology Transformation Services

Looking for U.S. government information and services?
Visit USA.gov