There are multiple people who are completely against gmo salmon because it hasn't been around long enough to see what the effects are.
The FDA (Food Drug Association) has approved the sale of the salmon without it being labeled as genetically modified.
Most people don't know if there eating gmo salmon. Or just regular farm grown salmon
The growth hormone from the North Atlantic king salmon was integrated. The North Atlantic king salmon is the largest breed of the Atlantic salmon.
The promoter from the ocean pout a eel like fish promotes the growth gene and basically never shuts it off making the fish never stop growing.
This trait makes the fish grow very rapidly.
Pros and Cons
A few pros are that the fish is leaner and more healthy and doesn't have disease risk. The fish is a lot bigger.
Cons are that we're not yet shire what problems eating them may present. Also there's a possibility that the get into the wild that they may drive out a native species.
GMO salmon was created by scientists at auqua advantage fish.
By the time a wild salmon is born caught and on your plate it can be multiple years. The gmo salmon is about half that time. Also gmo salmon doesn't have a risk of disease wild salmon do.