The Pacific Islands Heritage Marine National Monument: Commercial Fishing Interests and Considerations for Congress

Strategic Insights -

The Pacific Islands Heritage Marine National Monument (PIHMNM) is a vast marine protected area in the Central Pacific Ocean, covering nearly 495,000 square miles, roughly twice the size of Texas. Established in 2009 under the Antiquities Act of 1906, the monument is one of five U.S. marine national monuments, designed to protect and conserve historic structures, ocean ecosystems, and other objects of historic or scientific interest. Since its expansion in 2014, the PIHMNM has been a subject of interest for Congress, with some Members proposing legislation and others expressing concerns about commercial fishing interests within the monument.

Key Takeaways:

  • The PIHMNM covers over 495,000 square miles in the Central Pacific Ocean, encompassing seven U.S. Pacific Island territories, most of which are uninhabited.
  • The monument is one of five U.S. marine national monuments, established under the Antiquities Act of 1906, to protect and conserve historic structures, ocean ecosystems, and other objects of historic or scientific interest.
  • Commercial fishing had been prohibited within the PIHMNM until April 17, 2025, when President Trump issued a presidential proclamation allowing commercial fishing in certain areas.
  • The U.S. District Court for the District of Hawaii granted injunctive relief to environmental groups, vacating the April 2025 NMFS letter, arguing that NMFS violated the Magnuson-Stevens Fishery Conservation and Management Act (MSA) and the Administrative Procedure Act.
  • Stakeholders, such as the Western Pacific Regional Fishery Management Council (WPRFMC), have welcomed the changes in the presidential proclamation, citing economic and other potential benefits of expanded fishing in the area, while others, such as Earthjustice, have expressed concern about potential environmental effects.
  • Congress may consider how executive directives in PP 10918 may align with MSA provisions, assessing the vulnerability of species protected by the PIHMNM to commercial fishing practices and evaluating perspectives in favor of and against the proposed national marine sanctuary.
  • The PIHMNM is jointly managed by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Fish and Wildlife Service (FWS), except for Wake Island and Johnston Atoll, which are managed by the Department of Defense.
  • The monument is part of the broader Pacific Island Territories, which have been impacted by ocean warming and acidification, with potential compounding effects from fishing.

Statistics:

  • The PIHMNM covers an area of 495,000 square miles, roughly twice the size of Texas.
  • Since 2017, no hooks have been set by the Hawaiian seasonal longline tuna fleet that seasonally fishes in waters around Johnston and Palmyra Atolls.
  • According to the Western Pacific Regional Fishery Management Council (WPRFMC), the combined amount of fish harvested from the area is on average less than 5% of the total U.S. purse seine harvest.
  • As of June 2025, some Western Pacific highly migratory stocks continue to be listed as overfished (Oceanic Whitetip shark) or as experiencing overfishing (e.g., Striped marlin).

Sources:

  • Congressional Research Service (CRS) In Focus white paper (No. IF13090), August 25, 2025, by Anthony R. Marshak.
  • National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS), and Western Pacific Regional Fishery Management Council (WPRFMC) documents.
  • 48 Federal Register 10605-10606, March 14, 1983 (Presidential Proclamation 5030).