Papahānaumokuākea National Marine Sanctuary | Office of National Marine Sanctuaries

Sanctuary Designation

NOAA designated Papahānaumokuākea National Marine Sanctuary on January 16, 2025 with publication of the final rule. Per the National Marine Sanctuaries Act, after the final rule for sanctuary designation is published, sanctuary designation will take effect following 45 days of continuous session of the U.S. Congress.

Designated in 2025, Papahānaumokuākea National Marine Sanctuary is America's 18th national marine sanctuary, and is the largest in the National Marine Sanctuary System. The sanctuary encompasses 582,570 square miles of Pacific Ocean waters in Hawaiʻi, providing protection to nationally significant natural, cultural, and historical resources while bringing opportunities for research, community engagement, and education and outreach activities. The sanctuary is coextensive with the marine portions of Papahānaumokuākea Marine National Monument, and is managed in partnership with the monument co-trustees.

Boundry map of Papahānaumokuākea National Marine Sanctuary

Map of Papahānaumokuākea National Marine Sanctuary showing sanctuary boundaries, which encompasses 582,570 square miles of Pacific Ocean waters in Hawai’i. Image: NOAA

National Marine Sanctuary System

The Office of National Marine Sanctuaries serves as the trustee for a network of underwater parks encompassing more than 629,000 square miles of marine and Great Lakes waters from Washington state to the Florida Keys, and from Lake Huron to American Samoa. The network includes a system of 18 national marine sanctuaries and Papahānaumokuākea and Rose Atoll marine national monuments.