Northwestern Hawaiian Islands

The Northwestern Hawaiian Islands form the older, northwestern portion of the Hawaiian volcanic chain. They extend from Nihoa and Mokumanamana in the southeast through French Frigate Shoals, Gardner Pinnacles, Maro Reef, Laysan, Lisianski, Pearl and Hermes Reef, Midway Atoll, and Kure Atoll. ¹ Most are low coral islands or reef systems, while Nihoa and Mokumanamana are steep volcanic remnants. Their arrangement records the movement of the Pacific Plate over the Hawaiian hotspot: volcanoes become older, more eroded, and more submerged toward the northwest. Coral growth has built reefs around the sinking volcanic foundations, producing lagoons, sand cays, and narrow islets. The region is remote, exposed to storms, and difficult to navigate, with enormous distances separating the small areas of permanently emergent land.

The islands and surrounding reefs support a concentrated but highly specialized Pacific ecosystem. Papahānaumokuākea contains nesting grounds for Laysan albatrosses, black-footed albatrosses, and other seabirds, while its waters provide habitat for Hawaiian green turtles, Hawaiian monk seals, reef fishes, sharks, and coral communities. Many species or populations are endemic to Hawaiʻi, and the isolated reefs have produced ecological communities unlike those around the main islands. ² The Northwestern Hawaiian Islands are protected through overlapping designations, including the Hawaiian Islands National Wildlife Refuge, the Midway Atoll National Wildlife Refuge, and Papahānaumokuākea Marine National Monument. The monument protects both terrestrial sites and a vast ocean area, restricting extraction and managing scientific research, cultural access, navigation, and other activities. ³

Native Hawaiian voyagers knew and used parts of the northwestern chain long before modern scientific expeditions. Nihoa and Mokumanamana preserve archaeological evidence of Native Hawaiian presence, and the islands remain places of cultural significance associated with ancestral and spiritual traditions. ² Later encounters brought sealing, guano extraction, feather collecting, and other commercial pressures; Laysan and Lisianski were especially affected by introduced animals and resource exploitation. The United States established the Hawaiian Islands Bird Reservation in 1909, helping create a federal conservation framework. Midway Atoll later became a military and aviation site and was central to the Battle of Midway in 1942. President George W. Bush created the marine monument in 2006, and its protected area was greatly expanded in 2016. ⁴

The chain’s conservation history includes dramatic losses as well as recoveries. The Laysan rail became extinct after habitat disturbance and introduced predators, while the Laysan duck survived on a single island before reintroduction efforts expanded its range to other protected sites. ⁵ Laysan also suffered a severe ecological collapse after rabbits introduced for food stripped vegetation from the island; removing the rabbits allowed restoration to proceed. French Frigate Shoals is a major seabird and turtle breeding area, whereas Midway combines wildlife habitat with roads, buildings, and remnants of military infrastructure. The monument is also a living cultural landscape: its Hawaiian name, Papahānaumokuākea, invokes the ancestral relationship of Papahānaumoku and Wākea and reflects stewardship principles that extend beyond conventional wildlife management. ¹

Atoll

A ring-shaped coral reef or island enclosing, or partly enclosing, a lagoon, commonly formed around a subsiding volcanic island.

Papahānaumokuākea

The Hawaiian name of the marine national monument and World Heritage site encompassing most of the Northwestern Hawaiian Islands.

Hawaiian monk seal

An endangered seal found primarily around the Hawaiian archipelago, with important breeding habitat in the Northwestern Hawaiian Islands.

Hawaiian Islands National Wildlife Refuge

A federal wildlife refuge protecting island, reef, and marine habitats in the Northwestern Hawaiian Islands.