Salmon are not carnivores
"Salmon and other fish-eating fish are pisciverous not carnivorous", according to an article by Dr. Brad Hicks in the latest version of Northern Aquaculture. "And it is more than semantics", Dr. Hicks explains.
"It is important to use the proper terminology because otherwise one is prone to develop a misunderstanding of the salmonid’s trophic level. For many years anti-fish farming crusaders have been demonizing
salmon farming because of the misplaced notion that salmon are top level carnivores (often being compared to tigers, etc.) and that it is not ecologically sound to be farming such animals. However, salmon
actually occupy the same trophic level as farmed terrestrial omnivores and herbivores. And it is as ecologically sound to rear salmon as it is to raise terrestrial omnivores such as chickens and swine, and
terrestrial herbivores such as cattle.
Salmon, tuna and other fish-eating fish are not top level carnivores. These farmed fish are at essentially the same trophic level as other commonly farmed animals. However, because farmed fish are
poikilothermic (cold blooded) and neutrally buoyant (do not require energy to maintain posture) they are some of the most efficient farm animals. Farming fish is a very efficient way to produce foods and
it is not the rearing of top carnivores as some fish farm critics would have policy makers believe".