. >> gupta: that's a strong statement, but it's one alexandra morton, a prominent environmental activistrying to prove for the past two decades. the idea of farming is something that most people are familiar with, cows and chickens and things like that. why should salmon farming be different? >> morton: these are not farms, these are feed lots. they're growing as many animals as possible, as fast as possible, in as small a space as possible. >> gupta: what worries her is what happened five years ago, when salmon farms in chile made news. >> in chile's northern patagonia, the salmon are dying. >> gupta: a highly communicable, and deadly, virus called and deadly, virus called infectious salmon anemia, or i.s.a., broke out on the farms in chile, and wiped out most of the farmed salmon there. >> morton: the story in chile's interesting because the virus, they think, got in there ten years before it actually went viral. and they were kind of fooling around with it-- "maybe it's here, maybe it's not. no, it's not here." and then, wham-mo, the thing just ignited. >> gupta: how bad did it get in