Deep-sea coral reefs a new frontier

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In the Atlantic Ocean off Florida’s coast, at 1,500 feet and deeper, the water is 45 degrees and pitch-black.

Yet life thrives there. Scientists are just beginning to explore this vast secret of the deep sea: extensive coral reefs and the marine creatures that live there because of them.

A scientific mission last month explored more than 800 square miles of ocean, from Jacksonville to the Keys, confirming the existence of several deep-water reefs and charting new sites.

Like the corals found in shallow, tropical reefs, deep-sea corals help form habitat for crabs, shrimp, fish and other marine life. Growing from the seafloor, the corals have produced massive cliffs through the centuries as new generations of coral grow atop the old.

Scientists already know that deep-water corals attract commercially important fish, offering protection for the young and places to reproduce for sea bass, snapper, porgy and rock shrimp.

Unlike the easily accessible tropical coral reefs, however, these deeper corals have many unknowns. Scientists suspect massive mounds of the corals are still undiscovered and that the habitats are vital to the overall health of marine life. Exactly what role the reefs play for the survival of fish populations and the benefit of people is unknown.

There are a few tantalizing possibilities, though. Early studies indicate that some species found only on deep-sea coral reefs have possible medical uses. A unique sponge, for example, is being used in cancer-treatment studies.

But first, researchers are still trying to answer basic questions such as: What is down there? And what lives there?

“With every expedition, every time we dive, we find more and more coral,” said Steve Ross, a University of North Carolina-Wilmington professor and the expedition’s chief scientist. “These coral reefs are extremely diverse and abundant and widely distributed.”

Research about the deep reefs off the Southeastern U.S. started in earnest only a decade ago, but the reefs are already federally protected. Officials declared more than 23,000 square miles of ocean off-limits to bottom trawling, a fishing practice that has destroyed similar reef systems off the European coast. Only one commercial-fishing group, a small outfit that catches golden crab, continues to trap the crustacean among the deep-sea corals, and it works with federal managers to limit the impact on the reefs.

For scientists, just reaching the reefs is a big obstacle because the corals thrive in depths of 1,300 feet to 3,200 feet, well beyond diving range for humans.

This year’s expeditions depended on the Jason II, a 9,000-pound, remotely operated vehicle from the Massachusetts-based Woods Hole Oceanographic Institution. Equipped with several cameras and robotic arms to collect samples, the Jason II was dispatched to the ocean floor for days at a time, exploring seven key reefs.

Carrying the vehicle, 56 researchers and crew for the 15-day expedition was the Ronald H. Brown, the largest ship of the fleet for the National Oceanic and Atmospheric Administration. NOAA’s coral-reef-conservation program sponsored the trip, which included researchers from seven academic and scientific organizations.

Ross and Andrew David, a research-fishery biologist with NOAA Fisheries, said the Jason II proved invaluable in helping scientists advance their research into the corals.

“Sonar had suggested there was more coral, and we were able to confirm that,” David said. “There are several ongoing studies