Genetic engineering turns salmon into fast food

Transgenic superfish may be the next thing to hit supermarket shelves

  • Transgenic coho salmon compared to wild salmon

    COURTESY BOB DEVLIN
 

VANCOUVER, BRITISH COLUMBIA — The future has arrived at the federal Fisheries and Oceans Canada research lab. Here, coho salmon swim in a dozen large tubs. But these aren’t normal fish, says geneticist Bob Devlin. They’re genetically engineered research experiments.

To demonstrate the difference, Devlin scoops a handful of fish-food pellets and walks to the edge of one of the tubs. If these fish were wild, the sight of Devlin would send them straight to the bottom of the tub — an instinct that has saved many a salmon from a hungry eagle or grizzly bear. Not these fish. While the scientist hovers above their tank, dropping fish pellets, the salmon slap their tails on the water’s surface and jostle each other for food.

More dramatic than the salmon’s behavior, however, is their growth rate. By inserting an extra gene from a sockeye salmon into these coho, Devlin has created a stock of “superfish” that grow four times faster than ordinary coho. A strain like this could mean huge profits for fish farms, which grow salmon in net pens in the coastal waters of countries such as Canada, Chile, Norway and the United States.

But Devlin’s fish aren’t for sale. Rather, he sees himself as the “what-if” guy: What if these superfish fell into the hands of aquaculture companies, and then escaped into the ocean? What if they bred with wild salmon? “The research so far tells me that we should be careful, that we need more information,” he says. “I’m not willing to say there is no risk for the ecosystem.”

Despite concern from Devlin and other scientists, the biotechnology industry isn’t waiting around. At least one company has already developed a transgenic superfish, capable of growing up to six times faster than a normal salmon. The company wants to sell it to aquaculture companies, which supply salmon fillets to supermarkets nationwide. The proposal is now under review by the federal Food and Drug Administration.

“Huge potential” — good and bad

Tinkering with the DNA of salmon is a relatively simple task in today’s genetics labs.

In order to create fast-growing salmon, geneticists insert an additional gene, taken from a different species, such as an ocean pout, into a newly fertilized egg. If all goes smoothly, the foreign gene integrates into a long strand of native DNA, and a healthy fish — containing the combined genes — grows up. Geneticists then breed these modified fish for several generations, until the offspring consistently carry the additional gene.

A/F Protein Inc., a biotechnology firm based in Massachusetts, began using this technique to create fast-growing fish over a decade ago, after wild cod and salmon populations plummeted on the East Coast, and rural fishing communities struggled to replace wild fisheries with fish farms.

“Transgenic fish offer huge potential,” says Joseph McGonigle, an A/F Protein vice president. Using these fish, industry could produce twice as many fish, he says, while cutting production costs in half.

But critics point out that hundreds of thousands of salmon escape into the oceans from fish farms each year. In the Pacific Northwest, scientists, environmentalists and fishermen worry that escaped transgenic salmon could compete with wild salmon for habitat, pushing endangered runs to collapse.

Wild salmon evolve with specific river systems and are highly adapted to local patterns of high and low water, as well as to a region’s habitat and diseases. If these unique creatures interbreed with transgenic fish, raised in hatcheries and net pens, their progeny may lose the traits necessary for survival.

Using a computer model, Purdue University researchers found that if 60 transgenic fish escaped and were introduced to a population of 60,000 wild fish, and if they bred with each other, the wild species would become extinct in 40 fish generations.

A/F Protein has pledged to sterilize its transgenic fish, but that’s a risky proposition, says scientist Anne Kapuscinski, a professor of fisheries and conservation biology at the University of Minnesota. Sterilization is never 100 percent successful. Furthermore, even infertile fish might try to breed with wild fish, wasting eggs and causing a population decrease. “There are huge gaps in the science,” she says.

Coming soon to a supermarket near you?

Scientific questions may or may not be answered before superfish hit the supermarket shelves. The Food and Drug Administration is considering A/F Protein’s salmon gene as a “new animal drug.” The FDA is also consulting with other agencies to assess the ecological impacts, since it has little experience in such matters.

Washington, the only West Coast state to conduct aquaculture in ocean net pens, banned transgenic fish last February. British Columbia, the Pacific Northwest’s aquaculture powerhouse, has no such rule.

“We have concerns, but there’s a limit to what we can do,” says Ken Burton, public affairs official for the U.S. Fish and Wildlife Service, one of two federal agencies that protects endangered salmon and their habitat. “We’re watching it, but I don’t know if that means much.”

So far, no fish-farm companies have expressed interest in genetically modified fish. As Vivian Krause, an aquaculture specialist for the fish-farming giant Nutreco, puts it: “We have enough public-relations problems as it is.”

So there’s no need to worry. Maybe.

“Remember, the aquaculture industry is in no way interested in this technology,” says Devlin of Fisheries and Oceans Canada. Then, with a slight pause and a grin he adds: “Not today.”

Rebecca Clarren writes from Portland, Oregon.

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