SAN FRANCISCO
07/19/2011 02:14 pm ET Updated Sep 18, 2011

Salmon Breeding: Genetically Modified Salmon Can Breed With Wild Species, Study Finds

By Susanne Rust

This article comes to us courtesy of California Watch.

Transgenic salmon may not be as interested in the opposite sex as their wild, robust counterparts – but they do have enough sex drive to alter natural populations.

That’s the conclusion of a team of Canadian scientists who observed the breeding behavior of laboratory-reared, genetically modified salmon and wild salmon for two years.

“It’s possible for genetic modification to enter wild populations through natural sexual reproduction,” Darek Moreau, a researcher in evolutionary ecology at Memorial University in Canada, told the Montreal Gazette.

The researchers say they’re not sure what the evolutionary and ecological ramifications of their results are. However, the study highlights the need to make certain that transgenic fish hatcheries are kept far from wild populations, where they could intermingle with native fish.

The research was published in the journal Evolutionary Applications.

The scientists examined genetically engineered Atlantic salmon that contained the same gene as ones created by AquaBounty Technologies, a Massachusetts-based corporation that is working to commercially harvest the modified salmon.

The AquaBounty salmon contain a growth hormone gene from a Chinook salmon and a genetic "on switch" from a fish known as the ocean pout.

The added genes allow the salmon to continue growing during the winter, a time when they usually wouldn't. The result: a salmon that can grow to market size in 16 to 18 months instead of the usual three years.

Last fall, AquaBounty Technologies overcame a major hurdle when the Food and Drug Administration concluded that the genetically modified fish were safe for human consumption.

This new study now puts the spotlight on the environmental threats posed by transgenic fish, and it suggests that if the fish were to escape, they could breed with natural fish.

AquaBounty was unable to respond to questions by Monday evening. However, the company's website indicates it only “markets” sterile females. The Canadian study looked at males.

But as Charles Margulis, spokesman for the Oakland-based Center for Environmental Health, pointed out, “they need to create males to fertilize the eggs.”

Susanne Rust is an investigative reporter for California Watch, a project of the non-profit Center for Investigative Reporting. Find more California Watch reporting here.