Another reason NOT to buy farm raised ocean fish.
Salmon farming is just as bad for the environment (if not worse) than wild catching the fish, in my opinion. It is done by netting off big sections of natural water near coastlines and filling the area up with fish. Those fish are so overcrowded that they are putting more ammonia into the water system than it can handle--a far worse problem than the issue of farms leaching nitrogen fertilizers into the water, the fish farms are putting a much higher concentration into the environment! Being overcrowded, the fish are more prone to disease and parasites. The netting that keeps them in (at least, is supposed to keep them in) does not keep wild salmon fry from swimming into the area, picking up diseases they have no resistance to because they don't have to deal with it in the wild, and then swimming back out into the wild population, which can then be decimated by disease and parasites brought from the farm.