Deadly Norwegian disease found in BC’s farmed salmon is a game-changer


Deadly Norwegian disease found in BC's farmed salmon

The discovery of Heart and Skeletal Muscle Inflammation (HSMI) in BC’s farmed salmon has been couched in cautious and evasive terms by the industry and government. HSMI “might” have been found. It’s “yet another piece in the complex puzzle of salmon health on the Pacific Coast,” noted the former Minister of Fisheries, Hunter Tootoo.

Jeremy Dunn, executive director of the B.C. Salmon Farmers Association, also downplayed the significance of the announcement:

[quote]The findings announced by the SSHI [Strategic Salmon Health Initiative] regarding a potential diagnosis of Heart and Skeletal Muscle Inflammation in fish from one Atlantic salmon farm in B.C. are important. However, there is no consensus amongst the scientific community about the finding as the fish sampled in this farm showed no clinical signs of the disease.[/quote]

But the finding of HSMI is extremely significant. Understanding why requires some additional information.

Virus causes disease

HSMI is related to piscine reovirus (PRV) as HIV (human immunodeficiency virus) is related to AIDS (acquired immune deficiency syndrome). Salmon don’t get HSMI unless they have PRV. Just as HIV is asymptomatic, PRV is also asymptomatic — which explains why it is not technically called a “disease”. In its early stages, HSMI may also exhibit no “clinical signs of disease”. But it can be fatal.

HSMI is the symptomatic stage of PRV. As the degree of PRV infection increases, heart muscles are damaged, organs are impaired and muscles are compromised. Eventually fish are so debilitated by a weakened heart, malfunctioning organs and inflamed muscles that they are unable to swim.

HSMI is now the third largest cause of mortality for salmon farming in Norway. But this is the industry’s problem. The real environmental concern is the spread of PRV and HSMI to wild salmon.

A BC-raised farmed Atlantic salmon with signs of HSMI (Alexandra Morton)
A BC-raised farmed Atlantic salmon with signs of HSMI (Alexandra Morton)

Virus can spread quickly

PRV is extremely infectious. First identified in Norway in 1999, it spread quickly to 417 farms, and in 2010 was identified by Norwegian scientists as the cause of HSMI. On July 9, 2010, the scientific journal, PLOS One, published “Heart and Skeletal Muscle Inflammation of Farmed Salmon is Associated with Infection with Novel Reovirus” (Gustavo Palacios, W. Ian Lipkin, et al.), linking HSMI with this “novel” piscine reovirus. PRV eventually spread to BC, probably by infected eggs imported to salmon farms from Norway.

As early as 2008 reports from BC’s veterinarian pathology lab showed “congestion and hemorrhage in the stratum compactum of the heart” in farmed salmon, symptoms consistent with HSMI. Estimates are that most farmed salmon in BC now have PRV — not a serious problem if their fish don’t die of HSMI.

Wild salmon at risk

But the situation is very different for wild salmon. The PRV imported from Norway is now thought to be spreading to BC’s wild fish. As early as 2011, Dr. Kristi Miller found PRV in Fraser River sockeye. A year later, 13 of 15 Cultus Lake cutthroat trout were found with PRV. Norwegian scientists are of the opinion that HSMI may never be discovered in wild salmon because the fish would be too debilitated by the disease to survive predators and the challenging conditions of oceans and rivers.

The combination of PRV’s ubiquitous presence in salmon farms, its extreme virulence, and the fatal symptoms of HSMI could have devastating consequences for wild salmon populations.


About Ray Grigg

Ray Grigg is in his ninth year as a weekly environmental columnist for the Campbell River Courier-Islander on BC's Vancouver Island. Before this column, titled Shades of Green - now appearing on as well - Ray wrote a bi-weekly environmental column for five years. He is the author of seven internationally published books on Oriental philosophy, specifically Zen and Taoism. His academic background is in English literature, psychology, cultural history, and philosophy. He has travelled to some 45 countries around the globe.

14 thoughts on “Deadly Norwegian disease found in BC’s farmed salmon is a game-changer

  1. “Max” a fisherman from the prairies I believe the B.C.coast is one of the greatest natural fisheries in the world and it is now becoming extinct due to the side affects from fish farming.How can the people in control be so blind that they refuse to believe the destruction of the natural fisheries and that they are causing it?

  2. I well remember our government having the Norwegian fisheries representatives here to discuss the impacts of fish farms in their country before allowing them in ours. We were told unequivocally that if allowed fish farms,they would kill our native salmon stocks.
    Politicians are at best just corrupt front men for big business & lining their & friends pockets.Theres no room for honest people in court,cases are won by the best liars & their lawyers.Its all a very sick and corrupt game folks,screw what’s left of the natural world, it’s all about greed,power and money with expensive spin doctors to distract the brain dead public

  3. This just shows how toothless the legal/political system is in Canada– The Cohen Commission Identified the reasons for the decline of the salmon in BC– supplied the recommendations for stopping the proliferation of PRV/ HSMI . No Excuses Now Both the Federal Liberal and provincial Lieberal Lite( Neo Conservatives) have the proof to ban FishFarms in BC and DFO just extended the Farm licenses to 6 SIX YEARS from ONE.

    1. As the first Canadian Science researcher to be convicted of doing the science that I was given a written agreement to do, by a national committee I have witnessed the corruption first hand ,it is so deep that it is hard to imagine .New trial was ordered based on the lies of the provincial Director of Aquaculture and the aquaculture registrar .I was assaulted and my business premise’s searched by armed contractors who had no judicial authority and no search warrant ,prosecutor states that I gave minimal resistance ,mmmm to a man that is armed ,go figure .Province refuses new trial ,not in the public interest to bare the corruption that is so deep

  4. Easy-Peasy… get rid of the Liebrals. Then ban fish feedlots in the ocean. If they want to continue business they have to do it in land-based tanks, each with a sewage treatment system so the waste isn’t just flushed down the drain and into the river. If they don’t want to do it OUR way they can go back to Norway. They come here to do what Norway will no longer allow them to do there!

    1. The liberals were just elected last October. The courts ruled in 2009 fish farms are under federal jurisdiction.

      1. You need to look a bit further ,feedlot salmon started in NB ,and the team that took it to BC was mainly formed here and it was way before 2009

  5. Fish farms should never have been allowed especially for a fish species that is foreign to these waters and known to be more aggressive than our local stocks
    Eliminate the farms altogether, that might start to help our fisheries to recover from all the other calamities we’ve done to our natural resources in this Province.
    We have to stop thinking about the big dollars and look to the future. What will we leave for generations to come.

  6. Makes me weep….I grew up sport fishing…big schools of herring, needlefish, hake, shark..salmon everywhere…bit by bit B.C. waters become more and more barren…

    Run of river, habitat destruction, salmon diseases origination in penned up farmed fish..

    BC Liberals can’t destroy the wild salmon fast enough…and it’s true, once all BC.s wild salmon are gone…no need to protect rivers, or eagles, and we won’t have to worry about bears being shot, they’ll slowly die off…..salmon sustains our bears, eagles, and the forest itself…break the chain, all collapses..

    Makes me weep Rafe…I can barely force myself to read these BC salmon related articles..

    Good Day

  7. Greeaaaaaaat !
    Just what the wild salmon need along with the stresses of habitat loss, ocean acidification, lice, ocean warming……..lets see how Christy spins this into a “good” thing.

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