If this issue is of interest to you check out this article, Fish or frankenfish? FDA weighs altered salmon.  Also on my reading list is the book Four Fish: The Future of the Last Wild Food.

UPDATE: Greenwire reports, “Consumer and environmental groups want genetically engineered salmon clearly labeled in the supermarket, but the Food and Drug Administration demurred yesterday, saying that such labeling is outside its rules.  FDA is considering whether to approve the sale of salmon that are engineered to grow to full size in half the time as their normal counterparts.  If approved, the fish would be the first genetically engineered animal to enter the food supply. FDA said its rules do not allow labeling of a food merely because it is genetically engineered, and there needs to be outside reasons such as modified taste, nutrition or safety to warrant the action.”