Evidence of a heart disease that has devastated commercial fish farms in Norway has been detected in British Columbia.
The Strategic Salmon Health Initiative announced last week that it detected a "potential" Heart and Skeletal Muscle Inflammation (HSMI) in farmed Atlantic salmon samples collected from one B.C. fish farm located on the Johnstone Strait between 2013 and 2014.
The disease, which is not considered a health hazard for humans, did not kill the farmed Atlantic salmon. But the costly bane of Norway's industry would not have been detected if scientists had not been able to follow the life cycle of farm fish from smolts to harvest.
"We don't know how common or distributed the disease might be," said Kristi Miller, a molecular biologist with the Department of Fisheries and Oceans who has been studying salmon health for 23 years.
Although two top fish disease experts confirmed the diagnosis, DFO researchers did not explain why the press release described the cases as a "potential" finding other than the fact that it did not cause any fish deaths.
HSMI first emerged in Norwegian fish farms around 1999.
Ten years later, it expanded geographically and accounted for 150 costly disease outbreaks a year with significant mortality on fish farms. The Norwegian Food Safety Authority made HSMI a reportable disease in 2008. It is not yet a reportable disease in Canada.
The 2015 annual report of Marine Harvest, one of the world's largest seafood companies, rates HSMI as the number three cause of mortality in its fish farms, which operate in Norway, Chile, Scotland, Ireland and British Columbia.
But until now, HSMI had not been detected in any B.C. fish farms or wild fish, although the virus associated with the disease is now common in penned Atlantic salmon and wild fish near fish farms.
According to scientific studies, the movement of infected fish from hatcheries to open nets appears to be one way that HSMI can spread to new locations. Lesions on the heart generally appear five to nine months after smolts have been placed in ocean pens.
Nobody knows what risk the disease may pose to wild salmon migrating by fish farms.
"We can't comment on the risk to wild salmon yet. We are not there yet with the study," said Brian Riddell of the Pacific Salmon Foundation.
Although no HSMI has yet been found in wild salmon, it is unlikely a sockeye or chum made lethargic by the disease would survive long enough in the wild to be captured and tested.
Huge changes on the survival and growth of young wild salmon have been observed in B.C.'s southern waters, and many citizens and experts suspect that fish farms, climate and other environmental issues may all be having an impact.
The Strategic Salmon Health Initiative is a unique scientific collaboration between the DFO, the Pacific Salmon Foundation and Genome British Columbia.
The researchers have collected samples from 26,0000 fish and will now use state-of-the-art disease detection equipment to test them for 45 different microbes that can affect wild and farmed fish in Canadian waters.
'No consensus': salmon farmers
In a statement on the DFO findings, the BC Salmon Farmers Association said "there is no consensus amongst the scientific community about the finding as the fish sampled in this farm showed no clinical signs of disease."
Yet the disclosure has already had an impact on the federal government.
Last week, the DFO backed away from a Federal Court of Appeal case that could make it legal for companies to transfer diseased farmed fish into open-net pens located near migrating wild salmon on B.C.'s coast. The DFO supported the appeal.
But now the DFO has asked and secured a five-month adjournment on the case, which involves B.C. biologist Alexandra Morton. Morton was one of the first researchers to raise concerns about the spread of diseases from fish farms to wild salmon.
The abrupt request, which officials said was due to "new information," reversed the government's earlier attempt to fast-track the appeal through the courts.
The Harper-era case concerns the legalities of transferring fish carrying known or unknown pathogens from freshwater hatcheries to marine pens for farmed fish, and the risks those diseases might pose to wild salmon.
It is well known that fish farms, just like any large feedlot, provide opportunities for the viral transmission of disease due to crowding of susceptible hosts in a small area.
The move took Morton by surprise. "The Harper government would never have backed down like this. I'm very encouraged and do applaud the Department of Fisheries and Oceans on the adjournment," she told The Tyee. "I'm actually baffled. I've never seen a government behave like this."
Morton added that she's "not sure if the government responded to public pressure or if they responded to the science, but there is an enormous amount of both. This is a very positive move."
In the last month more than 15,000 Canadians have sent messages to Fisheries Minister Hunter Tootoo to reconsider the government's position on the case, which was due to be heard on May 26.
Steven Postman, a federal justice lawyer, secured the postponement by informing the federal appeals court that "new information relating to matters raised on the appeals has come to the DFO's attention."
Postman added that the department "needs time to complete the analysis and determine if this information impacts its position on the appeals. The other parties may also want to consider whether their positions are impacted. DFO is conducting a preliminary review of the information and will provide it to the parties in the coming weeks."
That "new information" turned out to be the disease findings made by the Strategic Salmon Health Initiative study.
The appeal aims to overturn a Federal Court ruling last May that DFO must uphold the Fisheries Act and not allow the transfer of diseased Atlantic fish into netted pens in the Pacific Ocean.
The ruling also tasked the department with applying the precautionary principle, given the ease with which viral diseases can spread in the ocean.
The court gave DFO until September 2015 to revise and review licences granted to Marine Harvest and its 70 fish farming operations along Vancouver Island.
Instead, the Harper government and Marine Harvest appealed the decision on the grounds that the judge erred in law and that his decision was "unreasonable."
Marine Harvest, a Norwegian-based multinational, raises nearly one-fifth of the world's farmed salmon in Chile, Scotland, Ireland, Norway and Canada.
If the government eventually drops its appeal and the original decision stands, "and corporations can no longer use infected fish, the whole industry will have to change," Morton said.
Virus at heart of case
The heart of the case concerns the piscine reovirus (PRV), a pathogen associated with the HSMI disease that now plagues farmed salmon in Norway. HSMI impairs a salmon's ability to swim.
The virus was first reported to authorities in B.C. in 2010 after the intensification of fish farming along the B.C. coast.
According to the Journal of Fish Diseases, approximately 80 per cent of farmed fish now test positive for PRV, while an increasing number of wild fish also test positive especially along migration routes near fish farms.
A spokesman for Marine Harvest offered no comment on the case other than highlighting a 2015 press release on the appeal.
It states that, "the fish disease known as Heart and Skeletal Muscle Inflammation has never been detected in Canada, despite extensive testing of farm-raised and wild salmon. In addition, the piscine reovirus is known to be a relatively common and benign fish virus that existed in B.C. before salmon farming."
However, the company did respond to the latest finding by noting in a press release that "to date, samples of Marine Harvest Canada's farm-raised Atlantic salmon have been found negative for HSMI."
Morton, an independent biologist who lives on Malcolm Island, has long argued that the scientific evidence shows a connection between the disease in Norwegian-owned fish farms and the decline in wild salmon.
She sought a judicial review of the matter in 2013 after she discovered that smolts raised at a Marine Harvest hatchery near Sayward had tested positive for PRV. After being delivered to a corporate fish farm off Port Hardy, the fish remained positive for the virus.
She also argued that federal scientists had not done appropriate studies to gauge the potential risk of loading or exposing wild salmon to a "virus we know so little about."
Although the DFO scientists noted that "any role of PRV in the development of HSMI remains unclear," Norwegian pathologists and veterinarians commonly describe it as the central virus associated with significant and serious HSMI disease in Norway's fish farms.
Since 2008, Morton has raised concerns about the impact of industrial fish farms on wild salmon and ocean waters, including sea lice and disease exchanges in the Broughton Archipelago Musgamagw Dzawada'enuxw Territory, an area with the highest density of fish farms in B.C.
Justice Bruce Cohen's $37-million inquiry on the decline of sockeye salmon in the Fraser River recommended in 2012 that the DFO no longer promote fish farms.
Cohen also suggested that the DFO should make maintaining the health of wild salmon its first priority. The former Conservative government did not implement many of Cohen's recommendations.
The clustering of high-density animal feeding operations, whether on land or the sea to raise industrial quantities of protein (everything from pork to shrimp) can amplify bacterial and viral evolution and depress animal immune systems.
Recent studies show that these industrial facilities can generate many different pathways for diseases and parasites to move from crowded feedlots to wild animals. In recent years as fish and shrimp farms have expanded and intensified, explosive epidemics of emerging diseases have saddled the industry with dramatic economic losses.
These outbreaks have also threatened valuable stocks of wild fish and other ocean-going animals. The Strategic Salmon Health Initiative has now added to the evidence of how that may be happening in British Columbia.
Tyee Commenting Guidelines
Comments that violate guidelines risk being deleted, and violations may result in a temporary or permanent user ban. Maintain the spirit of good conversation to stay in the discussion.
*Please note The Tyee is not a forum for spreading misinformation about COVID-19, denying its existence or minimizing its risk to public health.