Some of the planet’s last largely untouched ocean ecosystems surround tiny, remote Pacific islands and atolls. Those places — home to thriving coral reefs, dense seabird colonies and abundant predators such as reef sharks and tuna — have been protected by the U.S. through a network of marine national monuments and sanctuaries that together cover more than a million square miles of ocean. Now, federal actions are rolling back parts of those protections and opening deep waters to commercial fishing.
The atolls themselves are geologic and ecological wonders. Formed as volcanic islands subsided and coral reefs grew upward, atolls became rings of low-lying islets that for millennia served as stopovers and cultural sites for Polynesian voyagers. Colonial plantation agriculture and World War II military development changed some islands, but many atolls remain among the wildest areas on Earth. They provide critical nesting habitat for millions of seabirds and act as oases that attract highly migratory species like tuna, creating tight ecological connections between surface-dwelling birds and deep-swimming predators.
Palmyra Atoll, one of the most remote, hosts a field research station run by The Nature Conservancy and periodic staff from the U.S. Fish and Wildlife Service, since its land is designated a national wildlife refuge. Scientists studying Palmyra have documented exceptionally intact food webs, with large coral colonies and unusually high densities of predatory sharks — evidence of healthy, functioning reef systems.
Researchers also track large pelagic species. Satellite-tagging of yellowfin and other tunas shows these fish congregate around atolls, and seabirds depend on those predators to drive schools of smaller fish to the surface for feeding. Those intertwined relationships helped justify the federal protections that have kept much of this ocean relatively undisturbed.
The federal protections began in the 2000s: several monuments were designated and later expanded, including Papahānaumokuākea in the Northwestern Hawaiian Islands and the Pacific Islands Heritage Marine National Monument. Papahānaumokuākea, established in 2006 and expanded in later years, is the largest fully protected conservation area in the United States. The monuments were intended to conserve biodiversity and cultural values and to create resilient ecosystems better able to withstand climate change.
That protection is now in jeopardy. In recent actions, the Trump administration announced it would allow commercial fishing in deep waters of several Pacific marine monuments and had previously opened parts of other monument waters to fishing beyond certain distances from shore. The administration framed the change as support for U.S. fishermen and domestic seafood markets. Hawaii’s longline fleet and industry groups favor expanded access, arguing that it would let them fish without foreign competition on distant high seas and help offset rising costs.
Conservationists, Native Hawaiian cultural practitioners, and many scientists strongly oppose opening these waters. Indigenous leaders emphasize the cultural and spiritual importance of the Northwestern Hawaiian Islands and note that Native Hawaiian organizations now participate in co-management of Papahānaumokuākea. They say the monuments protect not only wildlife but also living human traditions tied to those seascapes.
Scientists warn of ecological risks. Longline fishing targets tuna with thousands of baited hooks and can result in substantial bycatch. When fishing was allowed around the Northwestern Hawaiian Islands in 2015, the longline fleet discarded more than 7,000 sharks that year; some survived capture, many did not. Conservationists argue that removing protections will reduce ecosystem resilience just when climate change is increasing pressure on corals and marine life.
There is debate about whether protected areas around atolls benefit commercial fisheries through spillover — the movement of animals from inside reserves into fished areas. One 2022 study found yellowfin tuna catch rates rose by about 54% and bigeye by 12% after protections around Papahānaumokuākea were expanded. A 2024 study found no evidence that yellowfin became easier to catch but did estimate bigeye catchability increased by roughly 13%. Researchers continue to assess how highly migratory species like tuna respond to static protected areas.
Legal challenges are already underway. After the administration loosened rules for some monuments, conservation groups sued; a judge instructed agencies to follow a full regulatory process before changing fishing rules. NOAA is in the process of reviewing potential changes, and officials have not publicly answered questions about the likely ecological impacts.
Conservation and Native Hawaiian groups say they plan further legal action to oppose the openings, and advocates argue the monuments should retain the highest level of protection to safeguard biodiversity and cultural values and to help these ecosystems better endure warming oceans. Federal decisions on commercial fishing in some of the Pacific monuments are expected this year, and the outcome will determine whether these remote ocean refuges remain largely off-limits to industrial fishing or become new fishing grounds for American fleets.