ISA, also known as Infectious Salmon Anemia, is an influenza-like virus that can cause mortality in Atlantic salmon. First identified in Norway fish farms in 1984, ISA is an infection that has appeared in fish farms around the world. In 2007, it devastated 70% of farmed Atlantic salmon in Chile, and has been the cause of mortalities in Scotland and Norway as well. ISA has been known to be most damaging to Atlantic salmon, and while it has been detected in two of 48 sockeye salmon tested at Rivers Inlet on the West Coast, the effects on sockeye are unknown, but could be potentially fatal.
SFU professor Rick Routledge discovered the virus in two of 48 sockeye smolts collected as part of a long-term study he led on the collapse of Rivers Inlet sockeye.
According to Routledge, the only plausible source for the European strain of ISA virus that he found is contaminated eggs transported from Atlantic salmon farms to Pacific farms. Forty million Atlantic salmon eggs have been introduced into B.C. since 1986.
“ISA is a deadly exotic disease which could have devastating impacts on wild salmon and the many species that depend on them throughout much of British Columbia and beyond,” stated Routledge in a press release. “The combined impacts of this influenza-like virus and the recently identified parvovirus that can suppress the immune system could be particularly deadly.” [Read more].
The recent Cohen inquiry revealed that ISA symptoms have been reported in B.C. farmed salmon since 2006.