"Some of those guys bring up some fabulous corals," said David Barnard, a biometrician with the Alaska Department of Fish and Game in Kodiak. "The biggest ones I've seen are five or six feet high, reddish orange, and almost as wide. They are like a bush.

mushroom coral PHOTOS/Courtesy of the Alaska Fisheries Science Center

"Professional observers aboard the fishing vessels were curious," Barnard said. "They are biologists, so they have an academic interest. I got involved when I realized that the coral might become an issue." Some environmental groups have expressed concern over commercial trawlers they say are disrupting large areas of the ocean bottom inhabited by coral and sponges.

Now Barnard and Bruce Wing, a veteran fisheries research biologist in Juneau for the National Marine Fisheries Service Alaska region, have written a photographic field guide to Alaska corals. Copies may be downloaded from the Alaska Fisheries Science Center Web site at www.afsc.noaa.gov.

The 67-page book, "A Field Guide to Alaskan Corals," will aid observers, fishermen and others in identifying coral at the generic level. Conclusive identification of each species is nearly impossible without lab techniques at a microscopic level to help, Wing said.

"This visual taxonomy will help take some of the guesswork out of the field identification process. After a haul is loaded on deck, fishermen and observers can visually compare the corals to those in the photographic taxonomic record," he said.

As commercial fisheries have grown in the coastal waters of Alaska, so has concern over their impact on the ocean ecosystems.

"It would be nice to know more about the community aspect (of coral), (and) their importance to the ecosystem in general, and for finfish or shellfish," Barnard said.

The corals form structures like a bush or a tree, providing hiding places and foraging niches for certain species of fish. Lots of small shrimp, snails and other items that the fish feed on clamber around the coral, Wing said.

"What we have seen in the last 10 to 15 years is the longline fisheries are extending into deeper waters and the trawlers are also fishing deeper waters, where they are likely to encounter these corals," Wing said. "The fishermen are fishing new grounds that we have not previously had much of a chance to look at. They are coming up with bits and pieces of corals and asking what are they.

"We have seen areas that a trawler has gone through and as much as seven or eight years later, the coral hasn't regrown," he said. Some of the large red tree coral colonies, which grown 4 1/2 to 6 feet high, take about 150 years to grow, he said.

While bottom trawlers have been criticized for disrupting coral and sponges, longlines and fish traps can also do damage, Wing said.

"Longlines get tangled in it and keep pulling. If they pull it up, the coral and sponges die," he said.

Heaviest use of the field guide will probably be by professional observers, whose presence is mandated aboard vessels for a variety of commercial fisheries, Wing said.

"The observers will use the guide heavily because they are supposed to record these various items in the bycatch," he said.

"One of the things I've seen over 40 years as a fisheries biologist is they are starting to pay more attention to items other than commercial fishing, to non-commercial species who make up components of the ecosystem," Wing said.

Wing said he hopes to update the field guide in about five years, "because there are still many forms out there that we don't know very well. There are species out there we haven't even identified yet," he said. With the next edition, "by then, we will have another whole set of stories to tell," he said.