Fish Found Nowhere Else on Earth Thrive on Papahānaumokuākea’s Deep Reefs

Deep reef off Midway Atoll dominated by Hawaiian endemic reef fish species. Credit: Greg McFall/NOAA

Deep coral reefs in Papahānaumokuākea contain large concentrations of fish species found nowhere else on Earth. Hawaiʻi is known for its high abundance of unique species, but just how abundant was unknown until recently.

Previous studies, based on scuba surveys in water less than 100 feet, determined that on average 21 percent of coral reef fish species in Hawaiʻi are endemic – that is, unique to the Hawaiian Archipelago. More recently, PMNM divers used advanced technical diving to explore deeper reefs between 100-300 feet (the ‘mesophotic’ or deep reef zone) within the Monument.

They found that in waters 100 to 300 feet deep, nearly 50 percent of the fish observed over a two-year period were unique to Hawaiʻi. On some of PMNM’s deeper reefs, more than 90 percent of fish observed were unique to the region.

The ongoing explorations of Papahānaumokuākea continue to show that the islands, atolls and submerged habitats of the Monument are home to an amazing diversity of plants and animals, underscoring the value in protecting this area.

Read the Press Release.

View more pictures and video.

Read article about this study published in the Bulletin of Marine Science.