According to recent science reports,, some farmed salmon may contain high levels of dioxins. Mercury and polychlorinated biphenyl levels may be up to eight times higher in farmed salmon than in wild: salmon. Omega-3 content may also belower in farmed than in wild caught individuals, and in a different proportion to what is found naturally.

Salmon flesh is generally orange to red. in color, although there are some examples of white fleshed wild salmon. The natural color of wild salmon results from pigments found in the fish's diet of krill and other tiny shellfish. Artificial colorants are fed to farmed raised salmon because their prepared diets do not naturally contain pigments.

Chinook salmon, also known as king salmon, is the largest of all Pacific salmon frequently exceeding 30 lbs. Chinook has the highest fat content of all salmon, therefore it is the richest.

Consumingsalmon is considered to be reasonably healthy due to the fish's high protein, high Omega-3 fatty acids, and high vitamin D content. A simple rule of thumb is that the vast majority of Atlantic salmon available on the world market are farmed (greater than 99 percent), whereas the majority of Pacific salmon are wild-caught (greater than 80 percent).