SFU salmon study needs more analysis
The Daily News October 18, 2011
While the report from Simon Fraser University regarding a flu-like virus that is affecting the Atlantic salmon in fish farms and now found in wild sockeye salmon from B.C.'s Rivers Inlet is unsettling, it bears further scrutiny.
According to SFU researchers, these sockeye have tested positive for a potentially devastating virus called infectious salmon anemia and it has never been found before in the North Pacific.
ISA can be fatal to Atlantic salmon, especially those confined in fish farms. Its effect on wild sockeye is unknown.
Opponents to the fish farming industry were quick to jump on the study to paint aquaculture as the villain, spreading potentially deadly viruses to wild salmon.
The virus detected in sockeye smolts by Canada's ISA reference lab at the Atlantic Veterinary College in P.E.I. is the European strain of ISA, the same virus that devastated fish farms in Chile four years ago.
Despite more than 4,700 tissue tests for ISA being conducted on B.C. farmed salmon during the past eight years, not one has come back positive for the virus. And only two of the 48 sockeye
that were sent to P.E.I. were found to have the virus. That was enough to prompt wild salmon supporter Alexandra Morton to raise the alarm about ISA.
She has raised concerns about the possible presence of the virus in B.C. fish farms after seeing Ministry of Agriculture and Lands disease reports describing "classic" ISA-like lesions in farmed salmon. An investigation by the Canadian Food Inspection Agency found no risk of ISA at the sites identified by Morton, who dismissed the inquiry as "little more than a phone call."
Like the flu in humans, ISA can exist in a relatively benign form and then mutate into a more deadly version of itself, said SFU researcher Rick Routledge.
The juvenile fish that tested positive were migrating down Rivers Inlet. The smolts likely contracted the disease from adult spawners.
"That means the virus has been around for several years," he said. "The only plausible source of this virus is fish farms."
DNA testing on the virus could help determine its source, he said.
Cooler heads must prevail. There may be other sources of this deadly virus and it is still unknown if it will be as deadly to native Pacific salmon as it has been to other salmon stocks.
While usually found in Atlantic salmon, ISA has been found in herring. The virus devastated fish farms in Chile in 2007 and 2008, killing millions of fish and resulting in the closure of both fish farms and processing plants. Fish farms in Scotland and Norway have also suffered lethal outbreaks.
The discovery of this virus in Pacific salmon is worrisome but it would be wrong to jump to the conclusion that it was introduced by farmed Atlantic Salmon.
Yes, they are a possible cause for the introduction of ISA but herring could just as likely be the cause.
These are early days and opponents of fish farms are quick to jump on anything they can to criticize a growing industry on Vancouver Island that employs thousands of people.
If a definitive link between fish farms and ISA in Pacific salmon stocks can be determined, then Atlantic salmon should be banned from B.C. waters, until each fish has been studied to see if it carries the virus.
People shouldn't let alarmists or industry opponents' convince them that aquaculture is killing wild salmon in B.C.
It may well be but the science to prove that fact still doesn't exist.
