I happen to work in a meat dept for a grocery store. We have a lot of farm raised fish and shrimp. It is cheaper and more "stustainable" meaning, not over fishing or damaging their eco-system. Though, farm raised fish usually have color added and you dont really know what their being fed or how their raised. I know they did some studies in China and alot of their farm raised fish and shrimp were raised in sewage water (there was a documentary on 60 minutes). Not very pleasent. Atlantic Salmon for example is one of the few farm raised fish, kept in a cage in its natural habitat, just fed with some type of grains.
Farm raised is usually a more mild taste vs wild, has a stronger taste.