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Northwestern Hawaiian Islands


Hundreds of miles northwest of the eight Main Hawaiian Islands (MHI) are ten little known, remote, and rarely visited tiny islands, atolls and shoals that span more than 1,200 miles (1,931 km) of the North Pacific Ocean. These are the Northwestern Hawaiian Islands (NWHI). With coral reefs in general decline around the populated regions of the world, the NWHI reefs provide a unique opportunity to study and assess how coral reef ecosystems function when not affected by major human activities.


The coral reefs of the NWHI are spectacular and pristine ecosystems covering thousands of square miles in the United States. These coral reefs are the healthiest and most undisturbed of the United States reefs, and unlike most other present-day coral reefs, the NWHI reefs comprise possibly the last, large-scale, apex predator-dominated coral reef ecosystem on Earth.

The NWHI coral reefs and associated habitats harbor more than 7,000 species that include corals and other invertebrate animals, algae, plants, fishes, sea turtles, birds, and marine mammals. Many of these species are rare, threatened, or endangered; many are endemic, found nowhere else on Earth; and many more remain unidentified or even undiscovered to science.

A chart depicting the distribution of the Estimated 36,813 sq km of Potential shallow-water Coral Ecosystems in U.S. Tropical and Subtropical Waters
A chart depicting the distribution of the Estimated 36,813 sq km of Potential shallow-water Coral Ecosystems in U.S. Tropical and Subtropical Waters. (Ref. 13 Rohmann etal. , 2005)

Research and surveys from several scientific expeditions to the NWHI over the past five to six years, have shown the coral reefs to be in good to excellent condition. The corals were healthier and more vigorous than expected. In some areas, the abundance and number of species of stony coral were much higher, even double, than researchers had been led to believe from previous literature (Ref. 7). Some single coral colonies were found to be very old, indicating long-term stability of the ecosystem. Coral scientists also observed the presence of a wide variety of unique growth forms which are uncommon in MHI. Also, some rare species of coral in the main islands are abundant in the NWHI. From a fisheries' perspective, the most important finding was the abundance of large apex predators, such as sharks and jacks, compared to the MHI. Not surprisingly, unique and specialized habitats in some areas harbored undescribed, and possibly endemic, species of sponge. Initial surveys found no invasive marine invertebrates in the NWHI except in the inhabited Midway Atoll. This is in dramatic contrast to the MHI where many marine invertebrates have been introduced via shipping traffic. However, terrestrial alien insects were found on all islands, and terrestrial alien plants were found on all islands except Gardner Pinnacles. Scientists noted an uneven distribution of corals, fishes and marine plants across the NWHI. For example, there seemed to be a higher number of gray sharks (Carcharhinus amblyrhinos) in the southern NWHI, whereas Galapagos sharks (Carcharhinus galapagensis) were more abundant in the north. There were marked differences in percentages of coral cover and kinds of species between the basaltic volcanic islands and the carbonate atolls.

A Presidential Order in the year 2000 designated nearly 100,000 square nautical miles (342,990 km2) in the NWHI area as a marine reserve, restricting both commercial and recreational fishing. The islands, shoals, atolls and reefs in this reserve is the largest nature preserve ever established in the United States and the second largest marine protected area in the world (after the Australian Great Barrier Reef).  Limiting fishing has helped this ecosystem thrive, but it's still not immune from outside threats. NOAA’s National Marine Sanctuary Program (NMSP) has begun the process to designate the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve (Reserve) as a National Marine Sanctuary under the National Marine Sanctuaries Act (NMSA).

On June 15, 2006, President George W. Bush used his authority under the Antiquities Act to designate the Northwestern Hawaiian Islands a national monument. On March 2, 2007, First Lady Laura Bush joined Hawaii Governor Linda Lingle in announcing a new Hawaiian name for the Northwestern  Hawaiian Islands Marine National Monument. The name is Papahanaumokuakea, which refers to Hawaiian genealogy and the formation of the Hawaiian archipelago. The name was adopted through consultation with the Native Hawaiian Cultural Working Group. This national monument will enable nearly 140,000 square miles of the Northwestern Hawaiian Islands to receive our Nation's highest form of marine environmental protection. The monument is managed by the Department of the Interior’s U.S. Fish and Wildlife Service and the Commerce Department’s National Oceanic and Atmospheric Administration (NOAA), in close coordination with the State of Hawaii.

The Papahanaumokuakea Marine National Monument will:

  • Preserve access for Native Hawaiian cultural activities;
  • Provide for carefully regulated educational and scientific activities;
  • Enhance visitation in a special area around Midway Island;
  • Prohibit unauthorized access to the monument;
  • Phase out commercial fishing over a five-year period; and
  • Ban other types of resource extraction and dumping of waste

This characterization of the Northwestern Hawaiian Islands touches upon the geography, cultural history, comparative biology, and conservation efforts to preserve the area. Recent scientific expeditions and methods of data capture are described, along with summary descriptions of individual islands, atolls, shoals, and banks. Links are provided to metadata and data catalogued with the NOAA Coral Reef Information System (CoRIS) The final statement is a 2005 assessment of the status and health of the coral reef ecosystem of the NWHI.

Quicktime Movie Slideshow of images taken in the NWHI during the 2002 Northwestern Hawaiian Islands Coral Reef Assessment and Monitoring Program (NOWRAMP) expedition. Images taken by professional wildlife photographer, James Watt. (39 MB, requires Apple QuickTime free viewer)