North Carolinians on Thursday night got their first chance to voice concerns about the Navy's plans for an anti-submarine warfare training range off the state's coast.

Environmental groups said the Navy underestimated the harm to marine mammals, including the endangered right whale. Fishermen said planned sonar exercises might hurt their livelihoods.

The hearing, attended by about 150 people, none of whom spoke in favor of proposal, was the second of three the Navy is holding at the three potential training range sites off the shores of Virginia, North Carolina and Florida. Federal law requires the Navy to gather public comment on its environmental study and respond. It expects to choose a site late next year.

A 660-square-mile rectangle of ocean about 50 miles off shore from Camp Lejeune is the Navy's preferred site to sharpen sailors' skills in using sonar to detect submarines. The Navy says that quieter diesel submarines pose a threat to American ships and that it needs to provide more realistic training.

"We used to see ships blowing up off the coast of North Carolina," said Navy Capt. Bill Toti of the Fleet Anti-Submarine Warfare Command. "The ships are as vulnerable as they were in World War II, but the submarines have gotten harder to detect."

Sonar is a technology that bounces amplified sound waves off objects or the ocean floor. The sound waves return as echoes. During exercises, crews on warships and aircraft use electronic receivers to receive the sonar echoes to detect the size, speed and direction of submarines.

The Navy currently conducts sonar training exercises off the Atlantic coast, including some off of North Carolina. The underwater range, to be built over a 10-year period at an estimated cost of $98 million, would provide a grid of hundreds of underwater microphones anchored on the ocean floor that would record ship movements and allow exercises to be reconstructed for study.

Joe Shute, an Atlantic Beach charter boat captain, wasn't convinced. Shute said he is worried that frequent use of sonar will drive away fish, which his customers pay for the thrill of catching. He said the range would cover some fishing holes that charter boats frequented. He said certain fish were quite sensitive to sound, and he turns off his depth finders to avoid spooking them.

"We have large military bases in Eastern North Carolina that bring in millions of dollars," Shute said. "I hope they remember the recreational and commercial fishing industries do the same thing. I'd hate to trade one for the other. "

Stephen Draughon, a charter boat captain speaking for N.C. Watermen United, said charter boat operators had witnessed a shutdown of migrating fish when the Navy was conducting sonar training. He said the group opposes the proposal.

The Navy says that fishermen could still use most of the waters, even when exercises are taking place.

Joseph Luczkovich, an East Carolina University professor and expert on fish acoustics, said the Navy's draft environmental study did a poor job of evaluating the effect of sonar. He said the sonar buoys would be emitting extremely loud blasts. He said fish would avoid the area.

Michelle Nowlin, a lawyer with Southern Environmental Law Center, said the environmental study grossly underestimated the presence of whales off North Carolina's coast, particularly the right whale. She said the Navy should extend the comment period, which ends Dec. 28, to take into account a report from the Marine Mammal Commission, an independent federal agency, on the effect of sound on sea life.

Mary Frazer, a representative of the North Carolina chapter of the Sierra Club, challenged the Navy's assertion that right whales are seen infrequently at the site. She said the Navy should do acoustic modeling of the effects of sonar on the endangered species.

"This is a large gap," Frazer said. "There is no room for margin of error with right whales. There is not enough data to remove that margin of error.

Toti said the Navy acknowledged there is a potential impact to marine mammals, but he said the Navy would take precautions to minimize the impacts. For example, the Navy would have lookouts aboard ships watching for whales and other marine mammals, if they are on the surface, and reduce the levels of sonar if spotted.

The Navy has concluded that sonar can seriously harm whales. A joint investigation by the National Oceanic and Atmospheric Administration and the Navy found that midrange sonar from Navy ships was the most plausible explanation for a stranding of 17 whales in the Bahamas in 2000. The animals had damage to the ears, possibly from exposure to sonar, that might have prompted them to become disoriented and beach.

However, the Navy said the proposed North Carolina location has vastly different underwater terrain.

The National Marine Fisheries Service is investigating whether Navy sonar played a role in the beaching of at least 37 whales, mostly pilot whales, near Oregon Inlet. It doesn't expect to release the results until after the comment period ends for the proposed sonar range.

John Costlow, retired director of the Duke Marine Lab, attended an afternoon open house held by the Navy to answer questions. Costlow said he had many questions about the proposal but was keeping an open mind. He said he'd like to see a century's worth of data comparing the frequency of whale strandings on North Carolina's coast before and after the Navy began using sonar during World War II.

"On a number of occasions, we've had beachings of pilot whales and some larger ones," Costlow said. "Nobody knows why."

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