A proposal to protect marine life by banning fishing in portions of the waters near California's Channel Islands fueled heated debate Thursday among fishermen and conservationists.

The state Fish and Game Commission is gathering public testimony on the plan, which could close between 12 percent and 34 percent of the area to commercial and recreational fishing.

The commission intends to hear additional public comment at an April 4-5 meeting in Long Beach before making a decision at its August 1-2 meeting in San Luis Obispo.

Conservationists and biologists say the state must take action to protect wildlife near the Channel Islands, a chain of five main islands about 25 miles off the coast of Santa Barbara and Ventura counties.

Fishermen and sport-fishing operators warn such a move could put them out of work.

Joe Cappuccio, owner of Del Mar Seafoods, said banning fishing near the islands would force fishermen to "dogpile" onto other areas.

"This is not something to be taken lightly. There are a lot of livelihoods at stake," Cappuccio told the commission.

Dozens of pro-fishing supporters in red T-shirts, many of them from the Los Angeles area, urged the commission to act cautiously.

Warner Chabot of Ocean Conservancy, a San Francisco-based nonprofit organization, called for the state to adopt a "compromise" position that would ban fishing in 25 percent of the waters off the islands.

Chabot said the population of rockfish in the area has fallen 80 percent over the last 25 years, and other fish populations also have declined.

Just as lawmakers were visionaries in setting aside national park land decades ago, Chabot said, the commission members should be "visionaries for the next century by establishing Yosemites in the ocean."

The Department of Fish and Game recommended last year that the commission protect 25 percent of the islands waters. It would do so by creating 11 state marine reserves that would ban all fishing, a state marine park that would ban commercial fishing and one marine conservation area that would restrict fishing.

But after more than 500 fisherman and environmentalists verbally sparred at an August hearing, the commission ordered the department to prepare six alternatives which would protect between 12 percent and 34 percent of the waters.

The commission could also decide to make no change or it could delay a ruling until after December 2003, when it will consider the need for protected areas along the entire California coastline.