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U.S. Coral Eden Found; Others Saved From Destructive Fishing

Scott Norris
for National Geographic News
June 28, 2006
 
Large and diverse coral communities have been discovered in the deep,
cold waters of the Olympic Coast National Marine Sanctuary off
Washington State (map of
Washington
), scientists announced this week.

And in a separate but related development, coral and other seafloor communities in the North Pacific were today given sweeping new protections from destructive fishing practices.

Bottom trawling—fishing by dragging heavily weighted nets across the seafloor—has been a major concern for conservationists worried about protecting deep-sea ecosystems (read "Trawlers Destroying Deep-Sea Reefs, Scientists Say").

A new ruling by the National Oceanic and Atmospheric Administration (NOAA) bans bottom trawling in a 370,000-square-mile (958,000-square-kilometer) area off Alaska's Aleutian Islands (map of Alaska).

The closure creates the largest no-trawl zone in U.S. waters. The rule is intended to keep the region's deep-water coral and sponge communities safe, along with the marine life these ecosystems support.

A similar prohibition protecting 135,000 square miles (350,000 square kilometers) of seafloor stretching from California to Washington went into effect earlier this month.

But some environmental advocates say that the recent actions still fail to guard some of the most important areas of deep-sea coral habitat, including species-rich "coral gardens" discovered off the Aleutian Islands in 2002.

Deep Diversity

NOAA biologists first glimpsed the Washington coral communities in 2004 and recently completed a follow-up survey.

Working in sometimes heavy seas, the researchers used a remotely operated vehicle with powerful spotlights to observe and photograph marine life thriving in permanent darkness at depths ranging from 300 to 2,000 feet (91 to 610 meters).

In a teleconference Monday, the scientists said their most surprising find was the widespread occurrence of a stony coral called Lophelia pertusa.

This species provides the base for massive reef structures in the Atlantic Ocean but has only rarely been seen before in the Pacific.

"Our [Pacific] Lophelia was primarily growing on boulders or rock substrate and not forming its own reef," said NOAA biologist Ed Bowlby.

"However, many areas have yet to be surveyed, so we may still locate other Lophelia areas that might resemble their Atlantic counterparts."

In addition, Bowlby says, at least six species of coral known as gorgonians were present.

The 15 areas surveyed also yielded a rich array of deep-sea creatures, including crabs, anemones, sea stars (stafish), and sponges (related photos: coral reef color).

Like other deepwater coral communities, the sites appear to provide important nursery habitat for fish.

"We saw large aggregations of rockfish, including pregnant females," Bowlby said. "Shark egg cases were laid and entwined on the soft corals."

The vehicle's headlamp also revealed scenes of destruction.

NOAA researchers say that two-thirds of the Washington coral community they surveyed showed damage from recent fishing activities.

The biologists observed tracks of lifeless seafloor where bottom-trawling gear had passed over. In several locations, fields of Lophelia coral had been reduced to piles of rubble.

The areas surveyed lie only partially within the large strip of seafloor along the West Coast where bottom trawling is now prohibited.

"Unfortunately it looks like maybe half of the new locations are outside of the currently protected areas," said Michael Hirshfield, chief scientist for the environmental group Oceana, based in Washington, D.C., and Juneau, Alaska.

"We certainly hope that NOAA acts quickly to close them."

A Victory, With Compromises

Meanwhile Hirshfield and other conservationists are celebrating what they say is a major victory in today's establishment of a no-trawl zone in the Aleutian Islands.

Oceana and other groups have lobbied for years for the new restrictions, ever since the discovery of coral ecosystems in the region. Their arguments were based on U.S. federal law that requires protection of essential fish habitat.

Hirshfield says the closure represents a compromise between conservation groups and commercial fishers.

"It's fair to say that not all the areas with known corals are as protected as we'd like to see," he acknowledges.

Still, Hirshfield says, the regulations will have an enormous conservation impact.

Bottom trawling is now prevented from spreading to greater depths and new areas where it doesn't already occur, and known coral gardens are protected, he says.

Directly or indirectly, the prohibition on bottom trawling is expected to benefit many of the Aleutian Islands' 450 species of fish and 26 species of marine mammals.

"We were able to close about 60 percent of the trawlable depths," Hirshfield said.

But John Guinotte, a biologist with the Marine Conservation Biology Institute in Bellevue, Washington, says the closures in the Aleutians and along the West Coast are only first steps toward coral protection.

He says the majority of the closure area in the Aleutians is too deep to fish anyway and is not known to have a high abundance or diversity of deep-sea corals.

"The area closed to trawling is colossal, but many of the most significant coral areas were not included," Guinotte said.

"The devil is always in the details. The devil in this case is that most of the Alaskan corals are not protected."

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