Salmon
The first genetically modified animal to be approved for food use (in 2015) was a salmon, where a growth hormone-regulating gene was modified to enable it to grow year-round, instead of just during the spring and summer.
There is very little in the way of independent studies on the potential health risks of these GMO salmon, the FDA choosing to rely on the producer for any safety information. There is also some concern about transparency into what information the FDA does have, as it apparently will not disclose some information during public review.
Farmed Versus Wild-Caught
As a very general rule, if you want to avoid GMO fish, it's probably easiest to go for the wild-caught variety. However, keep in mind that there are some differences: wild-caught salmon tends to be leaner and a bit more difficult to prepare.
Also, not all farmed salmon is genetically modified, but you often have to do some investigation to find out. The quality can also vary quite a bit depending on the producer and the techniques used. If you want the plump, high-nutrition product that a salmon farm can produce but without the GMO modifications, you can still find a few places. Some that I've personally discovered are the fisheries at the Faroe Islands.
My wife had been ordering Faroe Island salmon from qvc.com for a while; I can personally vouch for the quality when prepared for a meal. While researching information for these web pages, I became concerned that maybe we were supporting bioengineered fish farming; I couldn't find any references to the GMO status of these products. So I contacted the Faroe Fish Farmers Association with my questions and here was their response:
See also: