researchers have discovered a deadly bacterial disease in wild chinook salmon in the Pacific Ocean off Vancouver Island. Di Cicco says the next step is to determine what causes the disease in wild salmon and figure how the fish become infected. The disease is pretty well known in farmed fish, and it's a pretty severe disease where it can kill fish in a matter of days. as a risk to wild Pacific salmon, while other variants of the bacteria are not even considered in the assessment. Chinook salmon.