Genetically Modified Salmon Can Cross-breed and Pass on GM Material

If a genetically modified salmon were to breed with a brown trout in the wild, can it pass along its genetically modified traits? According to new research from Canadian scientists, the answer is yes.

Atlantic salmon generally mate with their own species, but the fish is capable of cross-breeding with the closely related brown trout. In a controlled experiment that mated transgenic salmon with non-genetically modified trout, about 40 percent of the hybrid offspring exhibited the genetically modified characteristic of the parent salmon.

A new study highlighted the potential risks of GM salmon escaping farms and passing their genetically modified material along the food chain.

The GM-hybrid fish grew faster than wild salmon, wild trout or wild cross-breeds of the two fish, according to Darek Moreau, from the Memorial University of Newfoundland, who spoke with the BBC. Moreau said the GM-hybrid fish could out-compete the GM salmon and wild salmon, taking the majority of the food during a mock up-stream test in the lab, significantly stunting the growth potential of the wild fish.

Researchers said the finding highlighted the ecological consequences of genetically modified fish escaping into the wild.   

AquaBounty, an American biotech company that created the GM salmon and is getting close to having their product become the first GM animal approved for human consumption, said the real risk of the salmon escaping is low and that all the fish the company is producing are sterile and kept in tanks on land.

AquaBounty created its transgenic salmon (marketed as AquAdvantage salmon) by modifying farmed Atlantic salmon with a growth-hormone gene from the Chinook salmon and a piece of DNA from the ocean pout, an eel-like creature in the ray-finned fish family.

"AquAdvantage salmon cannot escape or reproduce in the wild and pose no threat to wild salmon populations," the company writes on its website. The GM fish eggs are produced in Canada, then transported to a secure facility in Panama where they are grown to maturity.

Writing for the Huffington Post, Jocelyn C. Zuckermann said that AquaBounty acknowledges its sterilization procedure is not 100 percent effective, and that even with a failure rate of 0.1 percent, when fish are being farmed by the millions, there is always the potential for things to not go according to plan.

"Huge numbers of fertile fish could escape and interbreed with the already endangered Atlantic salmon, compromising its fitness and threatening its ultimate survival," she wrote.

Ron Stotish, CEO of AquaBounty Technologies Inc, said a 1995 study concluded that hybrids of Atlantic salmon and brown trout are born sterile.

"If this holds true, such a hybrid would pose little ecological threat as the fish would not reproduce," Stoish said, according to the BBC.

Stoish downplayed the new Canadian study and insisted there is no real risk posed to wild fish by his transgenic salmon.

"AquaBounty has stipulated that we will market only sterile, all female AquAdvantage salmon - with specific tests being performed on every commercial batch of fish to assure our product meets our specifications," he said.

"Overall, the study seems to present no new evidence for any added environmental risk associated with the AquAdvantage salmon."