Pacific sockeye salmon. (Photo: YouTube/PacificWildLive)
BC salmon may have exhibited virus for decades
Friday, December 16, 2011, 23:20 (GMT + 9)
Wild salmon in British Columbia (BC) waters have been found to carry what a federal scientist believes may be a new strain of the infectious salmon anemia (ISA) virus, which has afflicted fish farms in eastern Canada, Chile and Europe.
This the first time ISA has been found in Pacific sockeye, as before it had only been identified in Atlantic salmon, the Cohen Commission was informed.
First reported in October by Simon Fraser University researchers, this discovery has been refuted by the Canadian Food Inspection Agency (CFIA), which a month later reported that retesting the same samples failed to yield the same results.
However, the government said public agencies will generate a new surveillance plan to monitor fish diseases, The Canadian Press reports.
This time, the virus was found in BC sockeye and pink salmon tested at a Department of Fisheries and Oceans (DFO) lab, Vancouver Observer reports.
The potentially lethal virus has two dominant strains, Canadian and European, which have decimated Atlantic salmon in Scottish, Norwegian, Chilean and New Brunswick (NB) for decades.
Aquaculture opponents argue ISA proves the industry is harming wild salmon in BC.
Kristi Miller, head molecular geneticist at a DFO lab in Nanaimo, BC, said the pink and sockeye salmon tested for the salmon “flu” at her lab showed an ISA version 95 per cent similar to known strains.
“You can’t know things that you don’t have a (genetic) sequence for. And there is always a possibility that you will develop [a test] that will pick up other variants you don’t know about,” she testified before the Commission. “And I believe that’s what has happened here.”
Retesting 1986 salmon samples also revealed an ISA-like virus with a similar level of variation to fish tested in 2011, she stated.
The advanced variance of the virus found in the 1986 samples may “suggest it’s been here longer than that,” she added.
"I clearly believe that there is a virus here that is very similar to ISA virus in Europe, but we really do need to get a fuller sequence to get more information about how similar it is," said Miller. "Also, we have not established that it causes disease."
Pacific salmon may be immune to the virus, researchers noted.
Nellie Gagné, a scientist who operates a federal fisheries lab in Moncton, NB, said ISA strains have existed naturally for “thousands of years and they have evolved with their host.” To verify ISA’s presence in BC, she explained, more testing is required.
Moreover, Are Nylund, a Norwegian professor at the University of Bergen, who also testified, questioned Miller’s lab techniques and doubted their accuracy. He said there is currently “no hard evidence” to support the claim that ISA is in BC.
“Many indications it could be present in Pacific salmon but no hard evidence,” he stated.
The Commission is due to hear two more days of evidence on ISA before it issues a final report next June.
- Additional in-depth test results show no signs of ISA in BC
- Research finding ISA a decade ago was 'covered up'
By Natalia Real