Fishery managers in the North Pacific are expected Tuesday to endorse a reassessment of how to treat two large underwater canyons in Alaska’s Bering Sea that lie near one of the nation’s most profitable fisheries.

The move comes less than two weeks after scientists published new evidence that the region boasts significant deep-sea corals, sponges and other marine life. Environmentalists and some researchers have argued that the North Pacific Fishery Management Council should place part of the canyons off limits to fishing because little is known about them.

The Zhemchug and Pribilof canyons two of the world’s largest, plunging more than a mile deep are carved into the edge of the southeastern Bering Sea’s continental shelf.

Under federal law, regional fisheries councils such as the one in the North Pacific can set specific catch quotas or prohibit fishing in certain areas, subject to approval by the National Oceanic and Atmospheric Administration. Action by the council could have implications for how the nation’s commercially valuable pollock and Pacific cod fisheries are managed.

Bill Tweit, a member of the management council, said in an interview that the group is seeking “the best scientific understanding of what function the two canyons play in the larger Bering Sea ecosystem. He noted that several studies have come out since the council last considered the issue in 2006.

“After getting that [scientific update], we would then assess our current fishery management, as well as habitat-protection measures, and think about whether they’re adequate or not, said Tweit, who is attending this week’s council meeting in Anchorage.

Late last month, a group of scientists from the University of California at Santa Barbara, Greenpeace and NOAA published a paper documenting that the canyons are home to several long-lived coral species not previously thought to exist in the Bering Sea. Zhemchug Canyon is the world’s largest canyon, though it is not as deep as the Mariana Trench, which filmmaker James Cameron explored last month.

“It’s too important, ecologically as well as economically, to not set aside portions of that habitat as a buffer against uncertainty, as an insurance policy, said John Hocevar, oceans campaign director for Greenpeace USA and a co-author of the paper in the journal PLoS ONE.

The team surveyed the seafloor for three weeks in 2007 using DeepWorker submersibles small, single-pilot submarines equipped with high-definition video cameras, indexing lasers and robotic sampling arms along with a remotely operated vehicle. In addition to identifying 15 species of coral and collecting 20 sponge species, scientists documented 13 instances of fishing impacts at depths ranging from 328 feet to 3,280 feet below sea level.

Researchers later used software and algorithms developed by UC-Santa Barbara’s Center for Bio-Image Informatics to analyze more than 3,200 video frames from 16 dives.

“Contrary to expectations based on available evidence, the canyons do support areas of coral habitat that deserve attention, Bob Stone, a biologist with NOAA’s Auke Bay Laboratories, said in a statement.

1996-2012 The Washington Post