The Bush administration has launched a major push to expand the nation's fish-farming industry by allowing the farms to operate in the open ocean.

Officials of the National Oceanic and Atmospheric Association unveiled the regulatory proposal yesterday at the National Press Club, saying it would transform the way Americans raise and consume fish. The United States lags behind the rest of the world in fish farming, accounting for less than 3 percent of the world's aquaculture production. Most U.S. fish farms produce catfish or other freshwater species, not ocean fish.

Administration officials, who want to quintuple domestic fish farming by 2025, said the industry needs to dramatically expand to satisfy domestic demand for seafood and compete in the global marketplace. More than 70 percent of the nation's seafood is now imported, and at least 40 percent of that is farmed.

"We need to operate our fisheries in the U.S. as a business," National Marine Fisheries Service Director William Hogarth said at a news conference. "Wild-capture fisheries will not be able to meet future demand."

The proposal would establish a permitting process for farms in federal waters three miles to 200 miles off the coast, creating commercial zones that would operate under 10-year renewable leases. Bush officials and some scientists say submersible fish cages in the open ocean are less polluting and less vulnerable to being ripped open and allowing farmed fish to escape than in-shore fish farms.

"If done sustainably, aquaculture can provide the kind of industry and jobs local communities want," said Paul Sandifer, a member of the U.S. Commission on Ocean Policy, who now works for NOAA.

Fish farming, whether close to shore or farther out to sea, remains controversial. Raising large numbers of fish close together in pens can spread disease among wild and farmed fish, and the concentration of fish feces in the water can harm other marine life. Environmentalists also question farmers' emphasis on raising carnivorous species such as salmon, saying that obtaining the fish meal to feed them can destroy smaller fish populations.

Rebecca Goldberg, a senior scientist at the advocacy group Environmental Defense, said she is "really disappointed" in the administration's plan because it lacks a specific environmental standard for fish farms. Instead, the commerce secretary would determine whether such operations satisfy federal environmental rules in the course of issuing a permit.

Environmentalists do not want to stand in the way of offshore aquaculture, Goldberg said, "but it certainly needs to be done in a way that doesn't hurt marine ecosystems and doesn't cause harm to commercial fishermen's livelihoods or the pursuits of recreational fishermen."

NOAA Administrator Conrad C. Lautenbacher said offshore fish farming would "complement, not compete with, wild-catch fisheries," and officials would work to minimize environmental impacts.

It remains unclear whether the new regulatory plan will make it into law soon: Senate Commerce Committee Chairman Ted Stevens (R-Alaska) plans to introduce the administration's plan as legislation, but even he has concerns about the program's impact on commercial fishermen.

Cages submerged offshore pollute less and are less vulnerable to damage that allows farmed-fish escapes, proponents say.