Commercial fishing off the California coast faces tough new regulations as the state extended its ban on gillnets in state waters and a federal judge ruled that the National Marine Fisheries Service had not adequately protected bottom-dwelling rockfish.

Magistrate Judge James Larson of the U.S. District Court of Northern California ruled that the fisheries agency had not addressed the problem of "bycatch" -- the killing of juvenile fish, protected fish, marine mammals and birds --by commercial fishermen.

Marine scientists have noted for years that populations of Pacific rockfish,

a complex of about 80 species that are highly esteemed for food, are declining rapidly. Overfishing is widely blamed, and bycatch is considered a big part of the problem.

"The declines have been alarming, and this decision addresses that fact," said Drew Caputo, an attorney with the Natural Resources Defense Council, which together with the Ocean Conservancy filed the suit against the fisheries service.

"Fish processors want a constant supply of fresh fish," he said, "so NMFS has tried to accommodate that by allowing year-round fishing while simultaneously reducing landing limits," the amount of fish that can be unloaded at the docks on any given day.

Unfortunately, Caputo said, smaller and smaller landing limits mean it's easier and easier for fishermen to go over their quotas for specific species. "When they hit the quota, they just dump the excess overboard, compounding the problem," he said.

Zeke Grader, executive director of the Pacific Coast Federation of Fishermen's Associations, said fishermen understand the gravity of the bycatch problem.

"Everybody recognizes there is serious work that must be done to reduce bycatch, including fishermen," he said. "(Larson's) decision isn't necessarily a bad thing, depending on how it's implemented."

Eileen Cooney, the northwest regional counsel for the National Marine Fisheries Service, said the agency has not yet determined how to respond to the decision.

Environmentalists said the judge's ruling Friday means that the federal agency and the Pacific Fishery Management Council must rewrite the plan for management of the fishery. Among the measures environmentalists advocate are:

-- Incentives for commercial fisherman to fish with better, more selective gear.

-- More observers on boats so that a fishery can be closed quickly when quotas are exceeded.

-- Buying back boats and fishing permits to reduce the commercial fleet.

-- Establishing marine no-fishing refuges to restore depleted fish populations.

In a related matter, the California Department of Fish and Game has declared an emergency temporary ban on gillnets and trammel nets on the state's Central Coast to prevent the killing of sea otters, porpoises and sea birds.

The ban will cover waters from Point Reyes in Marin County south to Point Arguello in Santa Barbara County and augments a partial ban on the nets instituted in September 2000.

Gillnets and trammel nets are extremely effective in the catching of coastal fish such as halibut and white sea bass. They also have been implicated in the deaths of thousands of marine birds, including threatened common murres, as well as marine mammals.

The earlier ban permitted the nets in water deeper than 180 feet on portions of the California coast, but Fish and Game director Robert Hight said any use of the gear could seriously threaten birds, otters and other marine mammals.

The ban begins April 26 and runs three months. Members of the Fish and Game staff say the department will attempt to make the ban permanent.

Matthew Rutishauser, the science director for Friends of The Sea Otter, praised the ban but added that it must become permanent to fully protect vulnerable marine life.

"This move basically came about because a lot of murres and harbor porpoises were dying in the nets," Rutishauser said. "The federal government was threatening to step in under the (U.S.) Marine Mammal Protection Act unless something was done."