A company based in the United States and Newfoundland is seeking approval to supply Canadian diners with genetically modified salmon that grow twice as fast as normal fish.

Aqua Bounty Technologies has spent four years navigating the regulatory process in the U.S., but is still waiting to hear from that country's Food and Drug Administration.

Now Canada will be the second country where Aqua Bounty will ask for permission to sell GM salmon for humans to eat.

The fish, being raised in tanks at the company's facility in Prince Edward Island, carry a gene from another fish, called ocean pout.

That gene makes the salmon produce growth hormone year-round, resulting in fish that get to market in half the time.

The changes to the salmon's gene structure are minor, said Elliot Entis of Aqua Bounty.

"It's kind of like tuning up a car," he said. "The only thing that we've done is taken a car that gets maybe 20 kilometres or 10 kilometres to the litre and now it gets 40 kilometres to the litre."

Concerns about wild salmon populations

Other people have concerns about the fish, though.

Biologist Jeff Hutchings was a member of the Royal Society of Canada expert panel on biotechnology.

"If those fish were to escape and reproductively or ecologically interact with wild populations, then there could be some severe detrimental effects to those wild populations," he said.

Nadege Adam, a biotech campaigner working for the Council of Canadians lobby group, said consumers will never accept genetically modified salmon.

"We want to uphold the precautionary principle, which is: When in doubt, show us proof that it's not harmful," said Adam. "The consumers do not have the burden of proof here. The industry does."

Ottawa says it will evaluate all risks, both to human health and the environment, before deciding on Aqua Bounty's application. That process could take years.