Papahānaumokuākea Marine National Monument

Conserving Hawaiian culture and biodiversity

This fact sheet was updated in July 2020.


Papahānaumokuākea means “a sacred area from which all life springs” and is the Hawaiian name for the Northwestern Hawaiian Islands Marine National Monument. To Hawaiians, Papahānaumokuākea is a place of honor, believed to be the root of native ancestral connections to the gods, and the site to which spirits return after death.

The Papahānaumokuākea monument is the largest highly protected marine area in the world, encompassing 1.5 million square kilometers (582,578 square miles) of ocean. Made up of islands and water stretching from the island of Nihoa to beyond Midway Atoll, this area is home to more than 7,000 species, including 22 species of seabirds, 24 species of whales, at least a dozen species of sharks, four commercially important species of tuna, five species of endangered sea turtles, and monk seals. One-quarter of all species within the monument are found nowhere else on Earth.

The initial designation of Papahānaumokuākea in 2006 marked the first time a protected area of such significant scope had been established in the ocean, and it set a new standard for ocean conservation. With a 2016 expansion that greatly increased its size, the monument continues to inspire an international movement to safeguard large swaths of ocean and create the world’s first generation of great parks in the sea. Since 2006, more than a dozen large-scale marine protected areas have been created around the globe. As a result, close to 3 percent of the world’s oceans are set aside with strong protections. This is important progress, but the International Union for Conservation of Nature (IUCN) recommends protection of at least 30 percent.1

Conserving Hawaiian culture

Ever since their ancestors voyaged across the Pacific Ocean to reach these islands, Native Hawaiians have developed complex natural resource management systems and specialized skills to survive on remote islands with limited resources. They continue to maintain strong cultural ties to the land and sea and believe in the importance of managing the islands and waters as inextricably connected to one another. Native Hawaiians believe it is their responsibility to care for what feeds them, a principle known as Mālama ‘āina, which translates to “care for the land.”

Much of what is known about the area surrounding Papahānaumokuākea has been passed down in oral and written histories, genealogies, songs, dances, and archaeological finds. Through these sources, Native Hawaiians are able to recount how their seafaring ancestors traveled hundreds of miles between the Northwestern Hawaiian Islands and the main Hawaiian Islands.

In recent decades, there has been a renaissance of Hawaiian culture, exemplified by the Polynesian Voyaging Society’s Mālama Honua Worldwide Voyage, in which traditional canoes, the Hōkūle’a and Hikianalia, are circumnavigating the globe. The voyage, whose Hawaiian name means “to care for our Earth,” began in the Northwestern Hawaiian Islands and will end in 2017. Society members describe the trip as a call to protect cultural and environmental resources for future generations.

Honoring those lost in the Battle of Midway

The monument is the final resting place for thousands of American and Japanese sailors, airmen, and Marines who died during World War II. To honor their lives, then-Secretary of the Interior Bruce Babbitt in 2000 designated the Midway Atoll National Wildlife Refuge as the Battle of Midway National Memorial.

Historians call the Battle of Midway the turning point in the fight between the United States and Japan. The U.S. victory at Midway effectively stopped the advance of Japanese forces across the Pacific. The battle’s entire area of engagement lies within the borders of the monument. American forces sank four Japanese aircraft carriers in the battle—Akagi, Kaga, Soryu, and Hiryu—as well as a heavy cruiser, Mikuma. On the U.S. side, the ships lost included the aircraft carrier USS Yorktown and the destroyer Hammann. More than 3,300 people died in the battle.

Expeditions discovered wreckage from the USS Yorktown in 1998 and the Kaga in 1999. Many other wartime artifacts are believed to be in the monument.

Papahanaumokuakea 1
Naomi Blinick 2016 Naomi Blinick

Protecting biodiversity

The monument safeguards key ecosystems, including shallow and deep-sea coral reefs, seamounts, and pelagic zones. Doing so provides protection for organisms that range from microscopic phytoplankton and zooplankton to seabirds, large tuna, sharks, sea turtles, and marine mammals. Monuments of such a large scale also strengthen the health of surrounding waters because they fortify the biodiversity that travels beyond their boundaries. Those benefits, meanwhile, are boosted when there is a network of protected areas in the broader ocean.

Above the waterline

The Northwestern Hawaiian Islands are home to one of the largest groupings of tropical seabirds in the world, including 14 million birds from 22 species, 5.5 million of which breed in the areas annually. Eleven species are considered imperiled or of high conservation concern.

Breeding seabirds are likely to forage near colonies, though the distance they travel to feed varies, depending on the species, chick size, and dependence of their young. If they must travel a greater distance, they face increased chances of incidental death because of fishing vessels or other threats. Papahānaumokuākea protects important seabird foraging habitat, as well as vital reproductive, nesting, and nurturing sites essential to the survival of bird species that inhabit the islands.

For example, more than 98 percent of the world’s Laysan albatrosses nest on the Northwestern Hawaiian Islands chain.

The islands are home to nesting turtles. Ninety percent of the endangered green sea turtles in Hawaii nest in the Northwestern Hawaiian Islands. Hawksbill turtles, which are critically endangered, are known to nest on those islands.

Coral reefs

Shallow coral reefs within the monument’s borders provide habitat for thousands of species. Because of their relative isolation, the reefs can be a living laboratory where scientists can study shallow marine ecosystems in their natural state. In addition, if their health remains excellent, these coral reef systems create an area of resiliency for a changing climate.

Science is still increasing understanding of the birds in the Northwestern Hawaiian Islands. In 2016, a Laysan albatross named Wisdom, banded by scientists in 1956, returned to Midway Atoll and hatched a chick. At least 66 years old, Wisdom is thought to be both the world’s oldest bird and the oldest to successfully hatch a chick.

Hawaiian monk seals are the only marine mammal solely dependent on coral reefs and are the most endangered pinniped in U.S. waters. The entire range of the 1,100 endemic Hawaiian monk seals left in the Northwestern Hawaiian Islands is protected.

Papahanaumokuakea 2

Pelagic life

The large scale of the monument helps protect populations of sharks; tuna; sea turtles; and marine mammals such as endangered blue, humpback, and false killer whales.

Many fish, even some that swim great distances, could spend their entire lives within the boundaries of the monument. For example, scientific studies have shown that the range of travel for several tuna species, particularly yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis), may be in the hundreds, not thousands, of kilometers.2

Other pelagic species benefit from the monument. An average of 10,000 sharks were caught each year in the waters surrounding the Northwestern Hawaiian Islands prior to the expansion of the monument in 2016.3 With their role in the food web, tiger sharks, gray reef sharks, and Galapagos sharks are ecosystem regulators, and their populations can grow in these waters. Where they spend the majority of their lives is now protected—from nearshore to more pelagic zones farther out to sea.

Scientific studies show that marine protected areas result in more and bigger fish, as well as higher levels of biodiversity and fish biomass. When female fish are able to grow larger, they produce exponentially more healthy and viable eggs than smaller fish do.4 Research shows that the positive effects of conserving marine environments are enhanced when the areas are large, remote, highly protected, and long-established, and when the rules are strictly enforced.5 

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Todd Aki

Deep-sea life

The deep sea here is home to remarkably rich coral systems. While more is known about shallow coral ecosystems, it is now thought that there are more coral species living at great ocean depths than in tropical shallows.6 For example, the black coral (Leiopathes sp.), which is more than 4,000 years old and one of the oldest living organisms in the world, creates ornate, forestlike structures. If damaged by fishing activities such as bottom trawling, it would need hundreds of years to recover.7

The world’s underwater mountains, or seamounts, are thought to harbor a wealth of marine organisms, but most remain virtually unexplored. Seamounts support biodiversity-rich communities that are poorly understood, though scientists estimate that as many as 2 million species inhabit the deep sea globally, a range of life comparable to that of the richest tropical rainforests.

Marine reserves help build climate resilience

Marine reserves help bolster food security and climate resilience. Highly protected areas that safeguard species and ecosystem functions have proved to be six times more resilient than unprotected areas to the impact of climate change.8 Reserves of sufficient size support the ocean’s ability to combat, and recover from, climate change, acidification, and sea level rise. Additionally, by keeping marine life protected and in the water, these reserves boost the ocean’s effectiveness as a biological pump in the carbon cycle. Protection aids in the recovery and sustainability of biodiversity from shallower waters around coral reefs to the deeper ocean.

Enhanced monitoring and enforcement can thwart poaching

Enforcement experts say that the ability to conduct monitoring and surveillance activities is enhanced by prohibiting all extractive and destructive activities within a defined area. When an area is declared off-limits to fishing, the rules are clear and monitoring becomes easier. Enforcement is no longer focused on identifying which species a vessel is targeting or which types of gear are being used, but rather on whether there are any vessels in a nonfishing zone. A satellite technology and data analysis platform developed as part of Pew’s Eyes on the Seas project helps with this task. Pew partnered with Satellite Applications Catapult to create this cutting-edge technology that merges satellite tracking and imagery data with other sources of information, such as fishing vessel databases and oceanographic data, to help monitor waters around the globe.


In 2006, President George W. Bush’s designation of the Papahānaumokuākea Marine National Monument paved the way for marine reserves that were large, protected, remote, and closed off to commercial fishing. With the passage of time, the monument has taken on the last characteristic of a “gold standard” marine reserve: longevity.9

Over the last century, seven American presidents have acted to make Papahānaumokuākea the largest highly protected marine area in the world. Most recently, in August 2016, President Barack Obama increased the monument’s size using the federal Antiquities Act. The added area contains considerable cultural and scientific value, including threatened species with long links to Hawaiian communities and possible additional remains from the Battle of Midway.

The larger monument now protects more of the area’s biodiversity through the entire lifecycle. That includes safeguards for deep- sea organisms and seabird territories. At the same time, it preserves areas of scenic and cultural value to Native Hawaiians. Such a large protected area sets a standard for others to follow and will help ensure a legacy of marine resources for future generations.

About Global Ocean Legacy

Global Ocean Legacy, a project of Pew and its partners, worked with local communities, governments, and scientists around the world to protect and conserve some of our most important and unspoiled ocean environments. Together they established the world’s first generation of great marine parks by securing the designation of large, highly protected reserves. From 2006 through 2016, GOL helped secure commitments to protect 2.4 million square miles (6.3 million square kilometers) of ocean—an area 12 times the size of Central America.


  1. International Union for Conservation of Nature World Conservation Congress, Increasing Marine Protected Area Coverage for Effective Marine Biodiversity Conservation (2016),
  2. Ray Hilborn and John Sibert, “Is International Management of Tuna Necessary?” Marine Policy 12, no. 1 (1988): 31–39, http://www.; John Sibert and John Hampton, “Mobility of Tropical Tunas and the Implications for Fisheries Management,” Marine Policy 27, no. 1 (2003): 87–95, S0308597X0200057X.
  3. National Oceanic and Atmospheric Administration, Pacific Island Fisheries Science Center, “Hawaii Longline Fishery Logbook Summary Reports” (1991-2015),
  4. Molly E. Lutcavage et al., “Results of Pop-Up Satellite Tagging of Spawning Size Class in the Gulf of Maine: Do North Atlantic Bluefin Tuna Spawn in the Mid-Atlantic?” Canadian Journal of Fisheries and Aquatic Sciences 56, no. 2 (1999): 173–77, PFRP/reprints/lutcavage.pdf.
  5. Graham J. Edgar et al., “Global Conservation Outcomes Depend on Marine Protected Areas With Five Key Features,” Nature 506, no. 7487 (2014): 216–20,
  6. S. Elizabeth Lumsden et al., eds., The State of Deep Coral Ecosystems of the United States: 2007, National Oceanic and Atmospheric Administration, NOAA Technical Memorandum CRCP-3,
  7. E. Brendan Roark et al., “Extreme Longevity in Proteinaceous Deep-Sea Corals,” Proceedings of the National Academy of Sciences 106, no. 13 (2009): 5204–08,
  8. Peter J. Mumby et al., “Operationalizing the Resilience of Coral Reefs in an Era of Climate Change,” Conservation Letters 7, no. 3 (2014): 176–87,
  9. Edgar et al., “Global Conservation Outcomes.”
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