These two salmon are the same age, but one is genetically-engineered to grow twice as fast. (Aquabounty)

The U.S. Congress has voted to block the approval of genetically-modified salmon produced in part on Prince Edward Island, but the vote is not expected to stop sale of the fish.

AquaBounty, a U.S.-based company, is nearing the end of what has been a 15-year process to have its salmon approved for sale as food in the States. The salmon is engineered to grow twice as fast as normal salmon. The eggs would be produced on P.E.I., and the fish would be reared in Panama.

Last week, that process appeared to hit a snag when 10 members of the House of Representatives managed to place an amendment in a draft bill that would stop the review by the Food and Drug Administration. Aqua Bounty CEO Ron Stotish told CBC News Tuesday he's astonished a handful of people can sidetrack a 15-year science-based review.

"This is really more of a public relations ploy and an attempt to generate negative publicity," said Stotish.

Stotish and other experts don't believe this amendment will affect the process in the end. The FDA decision could come before the bill is passed, or the amendment might not survive the final vote.

The Atlantic Salmon Federation's Andy Goode expects politicking over the genetically modified fish will continue.

"This is just really the shot across the bow, so to speak, in this debate," said Goode.

The P.E.I.-based environmental group Earth Action believes the fish are a risk to environment, and co-founder Sharon Labchuk was happy to hear of the company's frustrations.

"It's taking a lot longer than Aqua Bounty bargained for, and I don't think they've seen the end it yet, even if this bill isn't as successful as the proponents would like it to be," said Labchuk.

AquaBounty stock took a big bounce on news of the vote, falling almost 50 per cent, but it had regained almost all of what it lost by Tuesday.