In a nation that loves big stuff–from cars and certain body parts–you’d think people would be pretty excited about a new line of fast-growing farmed fish.

And especially when the genetically modified (GM) fish pronounced safe last week by the Food and Drug Administration is being billed as cheaper to produce, therefore cheaper for the consumer.

But most of the excitement that greeted the FDA assessment was not what the promoters would have wished for.  Many environmental and health groups remain deeply suspicious of bioengineered foods.

The analysis was “misguided and dangerous,” says the Center for Food Safety.  Federal tests were “insufficient in determining the long-term, unforeseen consequences” of genetic engineering, says Wenonah Hauter, director of Food & Water Watch.

Such responses come as no surprise to the scientists and entrepreneurs in Massachusetts who have been working for a couple of decades to develop the genetic salmon technology. Few issues generate more controversy among environmentalists than the idea of genetic engineering of food.

GM foods such as soy and corn and other grains have been in our food supply for many years.  But the modified salmon promoted by AquaBounty Technologies of Massachusetts promises to be the first bioengineered animal protein–the first main course.

The salmon technology dates back more than 20 years, when a researcher in Newfoundland froze a tank of flounder.  To his surprise, the fish survived, and further research led scientists to discover an “antifreeze gene” that is part of the DNA of cold-water fish.

Scientists initially hoped to use that gene to develop a strain of Atlantic salmon that could be farmed in icy Canadian waters.  As gene-splicing techniques were developed, they learned that the same gene also controlled the rate of growth.

When injected into salmon eggs, the gene alters the way the fish’s natural hormones work, allowing it to grow to market size in half the time of normal farm fish.  That discovery was patented and now AquaBounty Technologies, of Waltham, Mass., could receive the FDA’s go-ahead to start producing the transgenic fish, now using a gene from Chinook salmon and the antifreeze “promoter” from another cold-water fish, the ocean pout.

The technology has many other potential applications, says Elliot Entis, the Harvard-educated seafood entrepreneur who has spent nearly 20 years promoting the idea. 

For genetic engineers, fish offer a number of advantages over most other animals.  A spawning salmon produces thousands of eggs, which do not have to be carried by the mother.  That greatly simplifies the task of implanting and cultivating fish in captivity.

So, when scientists implanted the antifreeze gene in Atlantic salmon back in the 1990s, they essentially created a new species.  But the newly created fish is identical to normal salmon–with the exception of one gene out of approximately 40,000 that comprise the creature’s DNA.

That single gene “allows the fish to reach market weight in half the time of traditional Atlantic salmon,” says Dr. Ronald Stotish, the AquaBounty CEO.

That fast growth cuts the company’s overhead costs by half, which gives them a huge economic advantage in a competitive market now dominated by Chilean and Norwegian salmon farms.

But the critics believe that the gene also creates a whole set of uncertainties and potential threats to human health or to the environment.  Hauter, of Food & Water Watch, warns that the fish have not been adequately tested for allergies or toxicity.

She cites a recent study that claims transgenic salmon could have a greater effect on the environment.  In particular, environmentalists warn that GM fish will inevitably escape into the open sea and compete with native fish.

Anticipating those arguments, AquaBounty says it will produce only female fish and all their fish will be 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.

Entis, a former AquaBounty CEO, still serves on the company board and finds himself swimming upstream as an unofficial spokesman for the embattled bioengineering industry.

People are predisposed to fear anything new–especially when it involves food and health, he says.

“I’d like to get rid of words like “genetically modified,'” he says.  “But I can’t.”

The industry’s challenge, he says, is to help people understand that genetic modification occurs constantly in the natural world.  Evolution continues to occur as a series of genetic mutations.  Most of those mutations fail, but those that succeed lead to new and more successful genetic strains.

“Over the centuries, we have been creating food hybrids using traditional methods–including the majority of fruits and vegetables we eat today.  And often those hybrids have crossed species lines.”

Bioengineering is a more powerful and precise form of hybridizing, because it condenses a process into a much shorter time frame, Entis says.  It can get salmon to grow faster, or make wheat more resistant to disease, or increase the nutritional value of rice.

“We should not condemn or be fearful of the technology,” he says.  “We need to use it to our advantage and to the advantage of the environment.”

In the case of salmon, Entis argues that bioengineered salmon, produced in the U.S., will use less fish food, and less energy for transportation.  It also adds to food safety, he says, because the hybridized salmon will be produced in land-locked and regulated plants, so any tainted product can be quickly and easily traced back to its source.

None of this satisfies the critics.  “What about the masses of corporations that will no doubt race to produce GM fish in the crowded open ocean facilities they already utilize?” asks Wenonah Hauter.  “These fish will likely escape from their floating pens.”

Entis can only sigh.  “At the end of the day, our salmon is still a salmon,” he says.