Opinion

Is a Virus Ravaging BC's Sockeye?

As pressure mounts to shine more light on the question, the politics get hotter.

By Crawford Kilian, 30 Jun 2011, TheTyee.ca

Spawning Fraser River sockeye salmon.

Stressed: Spawning Fraser River sockeye salmon. Photo by Matt Casselman.

The Cohen Commission has been quietly investigating the collapse of the 2009 Fraser sockeye run, but the reason for it may already be known.

If so, another problem threatens the wild salmon: treating scientific findings as an exercise in political message control.

Sometime in the last week of August, Dr. Kristi Miller is scheduled to testify before the Cohen Commission inquiry into the 18-year decline and, in 2009, collapse of the Fraser sockeye salmon run. Her testimony could provide a genuine explanation for that disaster, but that explanation could also foretell future collapses. And it may also bring into question the policies of the Department of Fisheries and Oceans.

Dr. Miller, a DFO scientist, published an article in the U.S. journal Science last January. She was trying to identify reasons why so many salmon die in the rivers just before spawning -- a phenomenon called prespawn mortality

By tagging some fish, and doing biopsies on them before returning them to the sea or the river, her team was able to create genetic profiles and track the fate of each of these profiles. As she wrote in the abstract of her article, "In ocean-tagged fish, a mortality-related genomic signature was associated with a 13.5-fold greater chance of dying en route."

That same "signature" was correlated with a 50 per cent increase in mortality among fish tagged in rivers, and even those that reached the spawning grounds were almost four times as likely to die without spawning.

The genetic profiles showed that many of the fish had been exposed to some kind of stress, and Miller closed her article by speculating that the stress could be a viral infection of some kind. By implication, the absence of the virus might have enabled millions of fish to reach the spawning grounds.

A likely candidate is the salmon leukemia virus (SLV). Scientists think it is endemic on the coast, and in the early 1990s it was a problem in the fish farms in the Discovery Islands off Campbell River, in the narrowest portion of the Fraser sockeye migratory corridor. But that was when they were raising chinook salmon; while they still farm chinook, they have largely switched to Atlantic salmon and say it's no longer an issue.

'Saying nothing could backfire'

The Miller article had a considerable impact, both scientifically and politically, and led to an interesting exchange at the Cohen Commission on March 17, when Dr. Laura Richards, the regional director of science for DFO was testifying. On page 29 of the transcript of her testimony, Brian Wallace quoted from an email by Dr. Miller:

"Laura does not want me to attend any of the sockeye salmon workshops that are not run by DFO for fear that we will not be able to control the way the disease issue could be construed in the press." (He did not quote the last sentence in her email: "I worry that this approach of saying nothing will backfire.")

Dr. Richards responded: "Well, that's very much a misrepresentation," and went on to say it was a departmental decision, not hers, and that more information was being gathered; hence the reluctance to go public with incomplete data.

When The Tyee wrote to Dr. Miller to ask about this, she replied:

"Unfortunately, I am not given permission to speak with anyone affiliated with the media until after I testify at the Cohen Commission.

"Please be aware, however, that past research on salmon leukemia, often termed plasmacytoid leukemia or marine anemia, had not actually identified a specific viral agent associated with this 'syndrome' (not considered a disease until a disease agent is discovered), hence it is very difficult to determine if the as yet unidentified virus associated with salmon leukemia [is] the same as that purported to associate with our genomic signature, but we are working on this. We have made some inroads, but I am sorry I cannot discuss these at the present time."

So we have powerful evidence that some kind of stressor, probably a virus, is recorded in the genes of millions of sockeye that died prematurely in the 2009 run. We don't know what that virus might be, but SLV is a reasonable candidate.

Another viral hazard

Meanwhile, yet another viral disease has emerged, one that could go through our wild salmon stocks the way smallpox ran through the Americas after the Spanish conquest of Mexico.

This is Infectious Salmon Anemia virus, or ISAV. It is a disease endemic to the streams of Norway and to the Atlantic salmon that spawn there. Norway's own fish farms have battled it since 1984.

Wild Atlantic salmon carry the virus, but only farmed fish seem to contract the clinical disease. An American document says sea lice may be vectors for ISAV, and fish that survive infection can shed the virus for up to a month.

The Norwegian fish-farm industry operates also in Chile, the Maritimes, and British Columbia, and in 1999 ISAV appeared in Chilean fish farms. There, it appeared in farmed coho. Salmon are of course not native to the southern hemisphere; the coho had been imported, along with Atlantic salmon from Norway. They shared the same net-pens. Since then, ISAV has broken out repeatedly in Chile, most recently last December and January.

ISAV has also appeared in Scotland, the Faroe Islands, and New Brunswick. B.C. may have its sorrows with sea lice and salmon leukemia, but as far as we know ISAV is still unknown in our waters.

Importing disaster

Biologist Alexandra Morton has been concerned that the disease might infiltrate into B.C. through imported Atlantic salmon eggs. As she noted in a post on her blog on May 12, she sent former fisheries minister Gail Shea eight letters between September 2009 and April 2011, asking her to protect B.C. from ISAV "by closing the border to Atlantic salmon eggs."

But not all Atlantic salmon eggs are equally hazardous. The outbreaks in Chile must have come from imported eggs, and they afflicted imported coho. Chile has no wild endemic wild salmonids to risk. A similar outbreak in B.C. fish farms could spread to wild salmon populations, which have never been exposed to ISAV. Those not killed outright might still suffer the kind of stress that has killed so many before they can spawn. ISAV also infects herring –- fish essential in the food chain from salmon to humpback whales

Since 2004, Atlantic salmon eggs imported into Canada have come from hatcheries in Iceland, which also has banned salmon farms from their marine waters because their wild fisheries are too important to them to risk. It has never had an outbreak of ISAV.

Complicating the problem of disease threats is the way DFO has handled them. Dr. Kristi Miller feared that official silence on her findings could backfire; it has certainly not been reassuring. Suppressing scientific findings for political reasons is self-defeating and weakens DFO's credibility.

Morton has also criticized DFO's confusing practices: It does not require foreign hatcheries (which might export Atlantic salmon eggs to Canada) to report ISAV. But DFO does have to report any ISAV outbreaks here in Canada.

Morton rejects official assurances that "measures are in place to deal with not only ISAV, but all fish pathogens of concern."

"I can't find any such 'measures,' Morton says. "...I challenge Gail Shea, Randy Kamp, Laura Richards and Andrew Thomson to validate their statement and tell us what measures were/are in place to 'deal with' ISAV as millions of Atlantic salmon eggs poured into British Columbia on their watch."

Transparency or secrecy?

Dr. Kristi Miller is not the only person who can't say what she knows. As a formal participant in the Cohen Commission, Alexandra Morton has obtained considerable information about disease issues, but to do so she had to sign an "undertaking" not to disclose what she's learned. Morton was complaining about this on her blog as long ago as April 30, and the issue has now reached the mainstream media.

The government's position seems to be that releasing scientific data to ignorant, sensation-hungry reporters will only confuse matters -- as if decisions on a major public resource could be made behind closed doors.

But if a disease like ISAV has actually been found in B.C., Canada must report it just like mad cow disease or any other animal illness. If data is being suppressed to spare DFO some embarrassment, DFO faces much worse embarrassment when the news does come out.

Dr. Kristi Miller's testimony in August may help clarify the specific causes of the 2009 Fraser sockeye collapse. But DFO's credibility, never high since the destruction of the cod fishery, is in danger of collapsing like the 2009 Fraser sockeye run.  [Tyee]

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