Leaders of 12 environmental groups ganged up on “supersalmon” Monday, demanding that the Food and Drug Administration conduct a thorough environmental study before deciding whether to approve genetically engineered (GE) salmon for the U.S. market.

 “How FDA approaches this first request for approval of a GE animal for mass production and human consumption will set a precedent for future GE animal applications,” the environmentalists warned in the letter.

The letter was signed by executives of the Ocean Conservancy, Sierra Club, Greenpeace, Union of Concerned Scientists and 8 other major environmental groups.

They reacted to efforts by AquaBounty, a Massachusetts biotechnology firm, to get FDA approval for a farmed Atlantic salmon that grows twice as fast as naturally produced fish, thus lowering production costs.  The company does this by modifying a single gene that controls the salmon’s hormones and rate of growth.

An FDA panel conducted hearings on the proposed “supersalmon” in September with no immediate recommendation, but the agency was reported to be leaning toward approval.

Genetically modified foods such as soy, wheat and corn have been part of the world’s food supply for many years, but AquaBounty’s salmon would become the first animal protein approved for human consumption.

The environmental groups focused their arguments on environmental concerns – the risk that modified salmon will escape into the environment, with unknown consequences for wild salmon and other sealife.

AquaBounty says it will eliminate that risk by producing fish that are both female and biologically sterile, incapable of reproducing.  In addition, they will raise their fish in enclosed, land-locked hatcheries where fish can’t escape into the environment.

Whatever the environmental risks, others ask: Are supersalmon safe to eat?

In their letter, the environmentalists did not address the question, other than with a generic statement that GE fish could harm human health.

George Leonard, aquaculture director for the Ocean Conservancy, said in an interview that a thorough environmental impact study, as requested, would address the issue of human consumption.  But, at present, there is not enough information to reach a conclusion, he said.

Could modifying a single gene make the difference?  “It depends which one you’re changing,” he said.

“Our concern is that, if the FDA approves this proposal, we will be making a major decision to move down the road toward broader use of modified foods,” he said.  “And we will be doing that without really asking ourselves: Is that what we really want to do?”

Aqua Bounty, however, insists that the fish they plan to produce will have all of the healthful qualities of a normal fish.  It will merely be cheaper to produce.

“We should not condemn or be fearful of technology,” AquaBounty founder Elliot Ennis argued recently.  “We need to use it to our advantage, test the individual products as the FDA is doing, but do not prejudge the results.”

Environmentalists who attack genetic engineering “seek to eliminate the process itself,” he said, “without trying to determine how it can be positively used.”