New version of salmon virus may have started in B.C., expert says

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Will Campbell – December 15, 2011

What may be a new variant of a potentially lethal virus that has decimated fish farms in eastern Canada, Chile and Europe has been found in B.C. wild salmon, an inquiry was told Thursday.

A federal scientist told the Cohen Commission infectious salmon anemia virus was found in B.C. sockeye and pink salmon tested at a Department of Fisheries and Oceans lab in Nanaimo.

That finding echoes a controversial October report by SFU researchers that claimed ISA - a virus previously found only in Atlantic salmon - had for the first time been detected in Pacific sockeye smolts.

The claim has been disputed by the Canadian Food Inspection Agency, which last month said it failed to find the virus after retesting the same samples.

The virus has two dominant strains - Canadian and European – scientists told the Cohen Commission, a federal investigation into the 2009 Fraser River sockeye fishery collapse. ISA is not necessarily lethal.

Those two variants have spread among and killed countless Atlantic salmon in Scottish, Norwegian, Chilean and New Brunswick fish farms since the European virus was first observed off the coast of Norway in 1984.

Fish farm critics say ISA is proof the industry is harming wild salmon in the province.

Kristi Miller, head molecular geneticist at a Department of Fisheries and Oceans lab in Nanaimo, B.C., said pink and sockeye salmon her lab tested for the salmon “flu” had a version of the virus divergent but 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 an assay” -- or test -- “that will pick up other variants you don’t know about,” she told the commission.

“And I believe that’s what has happened here.”

Miller also said her lab retested 1986 salmon samples and found those, too, had an ISA-like virus with a similar level of variation to fish from this year.

The advanced variance of the virus found in the 25-year-old samples may “suggest it’s been here longer than that,” she added.

Miller was one of four salmon virus experts testifying for the inquiry, which extended its hearing schedule to look into the virus.

Nellie Gagné, a scientist who runs a federal fisheries lab in Moncton, N.B., said strains of ISA have existed naturally for “thousands of years and they have evolved with their host.”

More testing needs to be done to establish the presence of ISA in B.C., she added.

Are Nylund, a Norwegian professor testifying via video link, questioned Miller’s lab techniques, saying they may have produced unreliable results.

The University of Bergen researcher said he’s not convinced the virus has hit the province.

He said there is currently “no hard evidence” to support that claim.

“Many indications it could be present in Pacific salmon but not hard evidence.”

The commission will hear two more days of evidence on the salmon virus. A final report is due next June.

Original article on Vancouver Observer website

Comments

Here are a few comments on this article regarding salmon virus:

1. Originally there were two Atlantic Ocean variants of ISA, east Atlantic and west Atlantic - not Canada. The east Atlantic strain was mutated into a virulent form in 1984 in Norwegian fish farms. From there it has spread most places they have set up shop: Note it is from a Kiibenge powerpoint presentation: http://fishfarmnews.blogspot.com/2011/10/isa-infections-world-wide-sine-1984.html.

Chile now has 28 strains of ISA. That is how quickly it mutates in fish farms. Their outbreak caused $2 bilion in losses, perhaps a quarter of a billion dead fish. Now there is no going back from ISA in Chile - where there are no natural Pacific salmon.

2. Other than fish farm imports of eggs/embryoes, other possible sources of the 'original' ISA in BC is the fish farms in Puget Sound that predate BC's, or from the feds attempt to establish Atlantics here in the first half of the 20th century - about 8 million were planted.

3. There has never been ISA in BC. There is only Atlantic Ocean ISA. That is why it is such a big problem if it has been introduced into BC. It could spread all around the Pacific Ocean from California to Korea.

4. I think it is fairer to say that Nylund made the comments about the 'hard' evidence earlier in the testimony than when Miller revealed her ISA results from the mid-80s. His data tables say he thinks it is likely ISA is in BC. What he meant is that they need virus isolates to sequence. Here is what he has stated in the past: Are Nylund, head of the Fish Diseases Group at the University of Bergen, Norway, has stated: “… based on 20 years of experience, I can guarantee that if British Columbia continues to import salmon eggs from the eastern Atlantic infectious salmon diseases, such as ISA, will arrive in Western Canada”.

5. Chinook salmon are killed by marine anemia. This may turn out to be a mutated strain of ISA. It has proven virulent in both Clayoquot Sound and around Quadra Island.

Dennis Reid