New Discoveries Tie Northwestern Hawaiian Islands to Johnston Atoll

Jacks (Uraspis helvola) over deep algal bed at Johnston Atoll. Credit: Greg McFall/NOAA

Members of a research expedition to Papahānaumokuākea Marine National Monument returned with specimens of new species of deep-water algae from the Northwestern Hawaiian Islands (NWHI), and the first recorded specimens of black coral from Johnston Atoll. They also saw and photographed more than 20 species of fishes never before recorded from the NWHI, and 15 species of fishes never before recorded at Johnston Atoll.

The team visited Nihoa, Mokumanamana, French Frigate Shoals and Laysan Island in Papahānaumokuākea Marine National Monument, and then Johnston Atoll National Wildlife Refuge in the Pacific Remote Islands Marine National Monument, approximately 860 miles (1,390 km) west of Honolulu. Johnston is regarded as a key "stepping stone" for a number of central and south Pacific marine species to colonize the NWHI. The findings represent a significant increase in the known biodiversity of Hawaiian coral reefs, and provides insights into how Johnston Atoll contributes to the diversity of our reefs in Hawai'i.

Table coral (Acropora cytherea) is common throughout the tropical Pacific and at Johnston, but in Hawaiʻi its distribution is limited to French Frigate Shoals and neighboring atolls. Credit: Greg McFall/NOAA

The team spent 26 days aboard the NOAA ship Hiʻialakai conducting research dives on deep coral reefs below 200 feet in the NWHI and Johnston Atoll. Scientists collected samples of fish, corals, other invertebrates and algae for population genetics analysis; surveyed deep coral reefs and associated reef fish communities; searched for invasive alien species of coral and algae; and conducted archaeological surveys of the Howland, a late 1800s whaling ship that wrecked at Johnston Atoll.

This expedition marked NOAA's first full deployment of closed-circuit rebreathers on a research cruise. Rebreathers recycle the gases that divers breathe, removing carbon dioxide and actively managing oxygen levels, allowing for extended dive times and more efficient decompression at depths not accessible using conventional SCUBA.

NOAA rebreather divers Daniel Wagner and Randy Kosaki conduct coral, algae, and fish surveys at 200 feet at Laysan Island in Papahānaumokuākea Marine National Monument. Credit: Greg McFall/NOAA

The scientific team included researchers from NOAA's Office of National Marine Sanctuaries' Papahānaumokuākea Marine National Monument and Gray's Reef National Marine Sanctuary, the University of Hawaiʻi, the Hawaiʻi Institute of Marine Biology, and the Bernice P. Bishop Museum.

Read the Press Release.

Watch video clips from the expedition.

To see more photos, click here.

Giant Moray (Gymnothorax javanicus) peeks out of coral. These very large eels, which can reach eight feet in length, are common at Johnston but rare in Hawai'i. Credit: Mark Royer/Hawaiʻi Institute of Marine Biology

This old growth coral colony at Laysan in Papahānaumokuākea Marine National Monument is something not often seen – it could be several hundred years old. Credit: Mark Royer/Hawaiʻi Institute of Marine Biology