Monday, December 10, 2007

Lemon corals and cauldron sponges at Papahānaumokuākea

Marine researchers have recently discovered stunning new coral and sponge beds in mile-deep water within the Papahānaumokuākea Marine National Monument.

(Photo: The lemon yellow bamboo coral at right was first spotted within the Papahānaumokuākea Marine National Monument from a Hawai'i Undersea Research Laboratory submersible during a recent cruise. Photo courtesy Papahānaumokuākea Marine National Monument.)

They used the Hawai'i Undersea Research Laboratory (HURL) deep submersible Pisces V to survey a volcanic ridge near Twin Banks and a seamount near French Frigate Shoals. The water was 3,000 to 6,000 feet deep.

Chris Kelley, the principal investigator for the work, said these will be the first of many new discoveries in the vast preserve. New discoveries from shallow and deep reefs seem are being announced from almost every scientific voyage into the region.

In part, that's because most of the monument is below SCUBA diving depths and has not been completely surveyed. The monument includes the 10 islands, atolls and reef complexes of the Northwestern Hawaiian Islands, which extend from beyond Kaua'i to Kure Atoll, more than 1,000 miles away.

“It's important to find ways to explore these deepwater ecosystems where the inhabitants are virtually unknown,” said zoologist Randy Kosaki, monument research coordinator with NOAA.

Among the recent finds are a lemon yellow bamboo coral that grows like a tree, and a giant sponge with a hole in it that researchers are calling “the cauldron sponge.”

“HURL has operated in Hawaiian waters for over 20 years and never before came across these species until last month,” the monument said in a press release.

The recent research trip, a 22-day voyage aboard the University of Hawai'i research vessel Ka'imikai-o-Kanaloa, was led by Frank Parrish of NOAA's Pacific Islands Fisheries Science Center and Rob Dunbar of Stanford University. Their work included a range of research objectives, including locating and mapping new coral beds, determining age and growth rates of precious corals, and studying current speed and direction around deep coral beds.

These beds of corals, sponges and other life don't blanket the ocean floor. They occur in patches, and these patches can be alive with life, providing habitat for crabs, anemones, oysters, urchins, barnacles, lobsters and fishes. They can attract foraging monk seals.

Two key research goals for the deep waters around the Hawaiian archipelago, according to a national deep coral report released this year, are to identify what's down there and to map its extent, and then to figure out how it fits into the web of life.

That requires “determining the important physiological and ecological components of deep coral ecosystems,” said the report, The State of Deep Coral Ecosystems of the United States: 2007.

It says that minimal bottom trawling, which has never been a big industry off the Hawaiian Islands and which has been banned for some time, means the coral beds of the deep waters around the archipelago should be in pretty good shape. They may be at some risk from lost longline and bottom-fishing gear and from the use of traps for species like marine shrimp.

The primary value of the beds of Papahānaumokuākea Marine National Monument may be to provide a better understanding of the role these beds play in the marine world.

“Being remote from the anthropogenic influences of the main Hawaiian Islands make them important biological reference sites for future research,” the deep coral report says.

© 2007 Jan W. TenBruggencate


For a copy of the report, The State of Deep Coral Ecosystems of the United States:2007, see www.nmfs.noaa.gov/habitat/dce.html.

For information on the monument, see www.hawaiiatolls.org, www.hawaiireef.noaa.gov and www.fws.gov/pacificislands.


No comments: