Papahānaumokuākea Marine National Monument
2020 State of the Monument Report


Papahānaumokuākea Marine National Monument is the single largest conservation area under the U.S. flag, encompassing an area of 582,578 square miles of the Pacific Ocean—an area larger than all the country's national parks combined. Home to the highly endangered Hawaiian monk seal, threatened green turtles, and many species found nowhere else on earth, the complex and highly productive marine ecosystems of the monument are significant contributors to the biological diversity of the ocean.

view of Nihoa island from a Polynesian voyaging canoe
Nihoa as seen from aboard the Polynesian voyaging canoe Hikianalia. Image: Brad Kaʻaleleo Wong/OHA

Despite multiple past and current threats, the terrestrial and marine ecosystems of Papahānaumokuākea are among the least modified in the Hawaiian Archipelago. Due to Papahānaumokuākea's isolation, past management efforts, and current regulations controlling access, impacts from local human uses have been relatively few, and thus its reefs and other resources are considered to be in nearly pristine condition across most of the region. Marine habitat condition in particular locations has, however, been impacted by derelict fishing gear, large storms, aggressive nuisance algae, and coral bleaching, though most locations have not been significantly affected and are in good to fair condition. In contrast, terrestrial habitats have been affected by past human activities that altered soils and vegetation, introduced non-indigenous species, and left behind contamination on many of the islands. These habitats continue to be affected by human activities taking place outside the monument, such as those resulting in the deposition of marine debris. Monument-wide, inland and coastal water quality parameters have indicated relatively good conditions. In contrast, oceanic and atmospheric conditions have been affected by accelerated sea level rise, increased frequency of storms, and increased regional sea surface temperature. Time series data on erosion are lacking for a majority of terrestrial and abiotic habitats in the monument, however limited studies and inference drawn from studies in the Main Hawaiian Islands indicate that some terrestrial habitats are severely eroding, and that submerged abiotic habitats, with the exception of lagoon settings, are likely experiencing gradual net erosion. Additionally, while information on known contaminant concentrations is limited, conditions appear to be improving overall at studied sites.

aerial view of North Island, Pearl and Hermes Atoll
An aerial view of North Island, Pearl and Hermes Atoll. Photo: NOAA

Most living resources in the monument appear to be in healthy condition, owing in part to years of layered protections by the co-managing agencies. Many populations of endangered and other vulnerable species appear vigorous, and endangered species status is largely attributed to factors inherent in isolated locations, such as limited distributions, small populations, and vulnerability to perturbations. Further, management actions such as translocations, non-indigenous species removal, and habitat restoration have successfully contributed to improvements in habitat quality and species abundance and distribution. Shallow-water coral reefs vary by location, with localized natural disturbance events and coral bleaching affecting different reefs. In contrast, deep-sea habitats remain in nearly pristine condition, with little disturbance. However, several concerns remain. Perhaps one of the most significant threats to living resources in the monument is global climate change and its manifestations, including changes in ocean chemistry, rising sea levels, and rising sea surface temperatures, with resultant coral bleaching, in addition to increased frequency and severity of storms. Other concerns include marine debris, diseases affecting both terrestrial and marine organisms, non-indigenous species that threaten native biodiversity and degrade habitats, and a reduced capacity for long-term resource monitoring and restoration activities taking place on land.

monk seal and turtle resting on a beach

The maritime, historic, and cultural resources in the monument vary in condition, ranging from good to fair, depending upon the resource, although in all cases, trends in the condition of these resources were assessed as declining. These resources are finite and non-renewable, and over time, natural processes of degradation occur, largely due to weathering, corrosion, and erosion. Though little can be done to prevent natural deterioration of these resources, the information they contain may be preserved through timely archaeological study, documentation, and conservation of artifacts.

This "2020 State of Papahānaumokuākea Marine National Monument Report" updates the 2009 Papahānaumokuākea Marine National Monument Condition Report, documenting the status and trends of Papahānaumokuākea resources from 2008–2019, unless otherwise noted. The report is intended to support ongoing adaptive management of Papahānaumokuākea by helping to identify not only the status of resources, but also gaps in current monitoring efforts, and causal factors that may require monitoring and management actions in the future. The report also provides a framework that can serve to inform discussions among resource managers, researchers, communities, and other stakeholders about preserving the integrity of Papahānaumokuākea.

Papahānaumokuākea Marine National Monument

Map of Papahānaumokuākea Marine National Monument and its location relative to the inhabited Main Hawaiian Islands
Map of Papahānaumokuākea Marine National Monument and its location relative to the inhabited Main Hawaiian Islands. View larger version of the map. Image: PMNM

Papahānaumokuākea Marine National Monument (PMNM) is one of the largest fully protected conservation areas in the world. It encompasses 582,578 square miles (1,508,870 square kilometers) of the Pacific Ocean. The monument, created expressly to protect an exceptional array of natural and cultural resources, was originally established on June 15, 2006 and expanded on August 26, 2016, under the authority of the Antiquities Act. The region has received previous protections, including designation of the Hawaiian Islands National Wildlife Refuge, Kure Atoll State Wildlife Sanctuary, Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve, Northwestern Hawaiian Islands State Marine Refuge, Midway Atoll National Wildlife Refuge, and Battle of Midway National Memorial. Subsequent international protections include designation in 2008 as a Particularly Sensitive Sea Area and inscription as the nation's first mixed (natural and cultural) United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage site.

Monument Co-Trustee Management

Four principal entities, collectively known as the Co-Trustees, are responsible for managing the lands and waters of the monument: the Secretary of Commerce through the National Oceanic and Atmospheric Administration (NOAA), the Secretary of the Interior through the U.S. Fish and Wildlife Service (USFWS), the State of Hawaiʻi through the Governor and the Office of Hawaiian Affairs.
A memorandum of agreement (MOA) among the Co-Trustees establishes a joint governance regime where all parties share in management and coordinate by jointly issuing permits for activities in the monument (Memorandum of Agreement [MOA], 2006, 2017). The Co-Trustees have established a goal to provide seamless and unified management in the spirit of cooperative conservation, and they are committed to preserving the ecological integrity of Papahānaumokuākea and perpetuation of its ecosystems, Native Hawaiian culture, and historic resources.

Integrated Management

The name Papahānaumokuākea is reflective of the region's natural and cultural heritage and its future as a vast, sacred, protected, and procreative place. Inscribed as a UNESCO World Heritage site for its outstanding natural and cultural significance (State of Hawaiʻi et al., 2008), Papahānaumokuākea is a place of deep cosmological significance to Kānaka Maoli (Native Hawaiians), with a revered kinship connection. Papahānaumokuākea's establishing laws, mission, and current management practices emphasize the incorporation of Native Hawaiian values and knowledge into everyday management. This principle is reflected in a Papahānaumokuākea motto, "where nature and culture are one," and operationalized through continuing efforts by managers to increase integration in all areas of management.