Extraordinary Facts About the World’s Largest Protected Area

This ghostlike octopod—nicknamed Casper by scientists, after the friendly cartoon character—was discovered in Papahānaumokuākea on a 2016 expedition led by the National Oceanic and Atmospheric Administration’s Office of Ocean Exploration and Research. Scientific expeditions to the Northwestern Hawaiian Islands continue to lead to the discovery of new species of fish, invertebrates, and algae.

Papahānaumokuākea is the only intact ecosystem in the Hawaiian Islands and an important destination for those engaged in the ancient practice of Polynesian voyaging. The traditional, double-hulled seafaring canoes pictured—Hōkūle’a (left) and Hikianalia—departed Hawaii in 2013 for a four-year circumnavigation of the globe as part of a Polynesian Voyaging Society effort to promote sustainable stewardship of the natural world.

The world’s oldest living organism—the deep-water black coral Leiopathes annosa—is believed to be about 4,265 years old and is found exclusively within the waters of the Hawaiian Islands at depths of 305 to 488 meters (1,000 to 1,600 feet). The deep-water coral started growing around the time that the ancient Egyptians were building their pyramids.

Papahānaumokuākea protects one of the largest groupings of seabirds in the world, with 14 million birds from 22 species. Wisdom, the Laysan albatross pictured in the foreground, is at least 65 years old and is thought to be the world's oldest bird. She returned to Midway Atoll in 2016 to successfully hatch a chick.

At least a quarter of the species in Papahānaumokuākea on land and sea are endemic—found nowhere else on Earth. Among those is the Hawaiian monk seal, one of the most endangered marine mammals in the world, according to the California-based Marine Mammal Center. Some places within the expansion area show what is known as 100 percent endemism—meaning that all species are found only there—at depths of 100 meters (328 feet).