According to CBC News, newly published research indicates that genetically-modified salmon could transfer their genes to wild populations. The study tested the breeding inclination and ability of male GM salmon (breeding females were not available to test) in two different laboratory scenarios, and found that they were willing and able to breed with wild fish. The lead researcher, Derek Moreau, notes that GM males are overall less successful fertilizers than their wild counterparts, but that behavior of his study's fish indicates that GM genes would be able to reach wild populations. The researchers also suggest that the safest way to rear GM salmon and protect wild stocks is to keep them sterile and raise them in contained, land-based facilities. Read much more, here.
Incidentally, AquaBounty, the company whose AquaAdvantage GM salmon is currently under federal review, says on its FAQ page that it will "market only sterile, all female" salmon grown in "physically contained facilities, similar to those used in the commercial trout industry."