Deciding to go for Farmed or Wild? Another choice you have to make at the market. Farmed fish has less protein, more fat and less flavour than wild caught fish. Most likely to contain residues of antibiotics and pesticides. Not to mention the high levels of cortisol, the stress hormone produced by the fish that are tightly crowded together in the fish farm pens and not allowed to be free in the open waters.
Farmed fish produced in large quantities are Salmon (also labeled as "Atlantic Salmon") Tilapia and Catfish. With the high rate of demand for fish - they are bred on a large scale making it cheaper and easily available. China is the largest provider of farmed fish varieties in the world.
Wild fish is more nutritious and tastes much better without the health threat related with consuming the residue of carcinogens found in high levels of fat. Wild fish is usually more expensive than the farmed varieties as they are caught in their natural environments, their diets are usually of a higher-quality and more diverse than farmed fish. Meaning, they are not fed antibiotics. Try to shop for wild fish whenever you can. If not - organic farm raised varieties would be the next best option.