Transgenic Atlantic salmon called AquAdvantage grow at twice the rate of their natural counterparts. These fish are the same age. AquaBounty

The AquAdvantage salmon, a genetically modified fish that grows year round and much faster than a natural salmon, has been approved for human consumption for years now (at least in the US). But one consistent hurdle to getting the “FrankenFish” on supermarket shelves is the suspected environmental impact.

Critics speculate that the AquAdvantage salmon, needing as it does so much more food than a natural salmon, could extinguish the food sources in a natural salmon’s habitat. They also worry about the possibility of interbreeding. But the FDA has officially given its mark of environmental approval, thanks to certain precautions AquaBounty, the company behind the fish, has taken. The Daily Mail says, “their fish are all sterile and grown in secure containers on land-based fish farms,” which is not entirely accurate; only 95% of the fish are sterile, and given how many fish could be produced, 5% is not an insignificant number.

Consumer’s Union, run by the folks behind Consumer Reports, is also concerned about the possibility that the fish will aggravate allergies, citing a not-very-thorough allergen study (the FDA tested only six fish, and did find “an increase in allergy-causing potential”). The bigger issue seems to be that the FDA has shown no particular desire to require markets to label AquAdvantage fish as genetically modified. Most non-organic vegetables sold in the US have been genetically modified in some way, as has the feed given to animals, none of which is labeled, but as this is the first genetically modified animal intended for direct consumption, advocacy groups want a clear label to set a precedent for the future.