The Incredible Hawaiian Marine Ecosystem

Most species exclusive to region

A school of manini graze on algae surrounding a coral reef in the Papahanaumokuakea Marine National Monument. (USFWS — Pacific Region/Flickr)

The Northwestern Hawaiian Islands (NWHI) don't get a lot of attention. This collection of about 10 tiny land masses and atolls constitutes just a collective 3.1 square miles, but next time you're in Hawaii, consider striking out their way. You'll discover an unparalleled haven of biological diversity.

A new study published in the Bulletin of Marine Science claims that the coral reefs in Papahanaumokuakea Marine National Monument (PMNM) might contain the highest percentage of fish species found nowhere else on Earth.

Scientists call these types of regional-exclusive species "endemic species." The Hawaiian Archipelago has long been known for its wealth of endemic species, both on land and in water, but the new study provides stats that suggest there are more of these species than previously thought.

In reefs located in shallow waters—less than 100 feet deep—21 percent of fish species are endemic. If you plunge to a depth between 100 and 300 feet, nearly 50 percent of the species will be unique to the Hawaiian Archipelago. Intrepid adventurers willing to go deeper than that will stumble across ecosystems where more than 90 percent of the species are endemic.

The islands, atolls, and underwater habitats that compose the NWHI are already the largest protected area in the United States. The new findings underscore the significance of that protection.

The fish species you'll find only in Hawaii include the Hawaiian squirrelfish, chocolate dip chromis, masked angelfish, and blueline butterflyfish.

So, scuba-diving and snorkeling hipsters: Are you ready to travel to the most unique marine ecosystem on the planet? We'll save a seat for you at the evening luau.

More Adventure