The virus has always been there just like the common cold for...

The virus has always been there just like the common cold for humans. The virus come from pilchard and it becomes transferable as they swim across the salmon cages and tend to manifest more when conditions are less than optimal. A good human example would be flu "outbreak" during the changing of seasons. Just like flu virus in humans, the virus tend to cause elevated mortality in smolts (baby fish) while adult fish would tend to just fight it off just like we get flu. Outbreak and whatnot is just an extremist left wing way to disseminate propaganda. I mean, how many people actually understands marine science or aquaculture?? Not many at all.