Transgenic Fish Show Extraordinary Growth Rates

Robert H. Devlin, a research scientist with Canada’s Department of Fisheries and Oceans and his colleagues are producing coho salmon that average 1,100 percent faster growth than normal.

One fish in his West Vancouver Laboratory grew 37 times faster than normal!< What Devlin and his group do is called transgenics, part of the new wave of scientific research known as molecular biology. Transgenics involves the movement of genetic material from one animal to another.

Devlin took the DNA (the gene) that controls growth hormone production in sockeye salmon and tinkered with the switch that turns it on. Then he copied it. Associate Tim Yesaki injects each fertilized coho egg with two billionths of a liter of Devlin’s “new” gene. After more than 3,000 eggs, Devlin’s gene is expressed about 6.2 percent of the time.

Devlin’s work induces up to 40 times greater production of growth hormone in each fish. The growth acceleration work has been successful in chinook salmon, Atlantic salmon, rainbow trout, and cutthroat trout.

The super-fast-growing fish are fertile and they pass on the increased growth rate capability. Devlin is currently producing 6- to 9- pound cohos in only two years versus the normal four to five years.

But Devlin is far from cavalier about what he does. Security in the laboratory is tight. All fish tanks are indoors inside a chain link enclosure festooned with various electronic monitors. All drains and inflow and outflow pipes are designed as the ultimate fish traps should anything go wrong.

“Personally, I’d be very upset if these fish got out in the wild,” he said with all the concern of the dedicated conservationist and angler he is. “The bottom line is we just don’t know much about these fish yet and it will be awhile before we do. Until then, they’ll remain in indoor tanks under lock and key.”

While it seems logical that fish that grow 11 times faster than normal might outcompete its native counterparts for limited resources, Devlin says they might also be outgrowing their immune systems or swimming abilities, too. That in turn might make them even more vulnerable than wild fish in nature.

“This technology is at least a decade away from use even in the aquaculture industry,” said Devlin.

Meanwhile in Newton, Mass., A-F Protein, Inc. is licensing its transgenic salmon called “Biogrow,” to aquaculture concerns in Scotland, Canada and Chile. A/F’s salmon only grow 400 to 600 percent faster than normal. A-F is also developing transgenic halibut and catfish.