The reason the fish farms have higher carcinogens is because of the feed given to the farmed salmon. It is largely made of trash fish, that is boiled down and concentrated. This is basically the "fatty" part of the fish that has a higher concentration of the carcinogens...from the oceans. The study also noted that it varies depending on where the fish were farmed. The ones from the UK, had much higher levels of dioxins, etc, than BC. What I was wondering is whether the samples of the fish were taken consistently from the belly or from the meat of the fish? I think the fish farms could go a long way to helping their cause by using better feed....