[Coral-List] New Paper on Hawaiian Mesophotic Coral Ecosystems

Kimberly Puglise - NOAA Federal kimberly.puglise at noaa.gov
Tue Oct 4 10:25:08 EDT 2016

A new publication that may be of interest to you entitled "A comprehensive
investigation of mesophotic coral ecosystem in the Hawaiian Archipelago"
published today on PeerJ (https://peerj.com/articles/2475/). The NOAA
issued press release is reprinted below and can be found at:

***Hawaiian deep coral reefs home to unique species and extensive coral

- Discoveries show these low light reefs may serve as refuge for some

NOAA-supported scientists working in the Hawaiian Archipelago are calling
some of the deep coral reefs found in the region’s so-called oceanic
“twilight zone” the most extensive on record, with several large areas of
100 percent coral cover. They also found that the deep coral reefs studied
have twice as many species that are unique to Hawaii than their
shallow-water counterparts.

This extensive study of the Hawaiian deep coral reefs, known as mesophotic
coral ecosystems, led to some incredible finds published recently in the
scientific journal PeerJ. These mesophotic coral ecosystems, the deepest of
the light-dependent coral reef communities found between 100 and 500 feet
below the ocean’s surface, lie well beyond the limits of conventional scuba
diving and are among the most poorly explored marine habitats on Earth.
Scientists used a combination of submersibles, remotely operated vehicles,
and technical diving to study these difficult-to-reach environments.

Of the fish species documented on mesophotic reefs, 43 percent were unique
to the Hawaiian Islands, which is more than double the 17 percent of unique
species found on shallow Hawaiian reefs.

At the northern end of the archipelago, in the recently expanded
Papahānaumokuākea Marine National Monument, nearly all of the species are
unique to the region, the highest level recorded from any marine ecosystem
on Earth. These findings could offer further insight into the monument’s

In Maui’s ʻAu‘au Channel, scientists discovered the largest uninterrupted
mesophotic coral ecosystem ever recorded, extending more than three square
miles at approximately 160 to 300 feet deep and including areas of 100
percent coral cover.

“The waters off Maui present the perfect environment for these mesophotic
reefs to exist,” said Richard Pyle, Bishop Museum scientist and lead author
on the publication. “The area combines clear water, which allows light to
reach the corals; good water flow enhancing food availability;  shelter
from major north and south swells, and a submerged terrace between the
islands at the right depth.”

Because of the challenges associated with working at such depths,
mesophotic coral ecosystems are less understood and often not considered in
coral reef management efforts. Overfishing, pollution, coastal development
and climate change threaten coral reef ecosystems worldwide, and increased
knowledge of mesophotic coral ecosystems will help characterize the health
of coral reefs in general, particularly in the face of increasing stress.

“With coral reefs facing a myriad of threats, these findings are important
for understanding, managing and protecting coral-reef habitat and the
organisms that live on them,” said Kimberly Puglise, an oceanographer with
NOAA’s National Centers for Coastal Ocean Science. “Some species studied
can live in both shallow and mesophotic reefs, and the species could
potentially replenish each other if one population is overexploited.”

“There is still so much of our ocean that is unexplored,” said W. Russell
Callender, assistant NOAA administrator for the National Ocean Service
“Working with academic partners and using innovative technology will
enhance our scientific understanding of these important habitats and
increase the resiliency of these valuable ecosystems.”

This paper, led by Bishop Museum, represents a collaboration of 16
scientists from five institutions and two federal agencies. The research
was supported by NOAA’s National Centers for Coastal Ocean Science, Coral
Reef Conservation Program, Pacific Islands Fisheries Science Center and
Papahānaumokuākea Marine National Monument, as well as University of
Hawaii’s Hawaii Undersea Research Laboratory and the State of Hawaii.

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