Marine Harvest workers processing farmed Atlantic salmon. | Submitted

Environmental organizations, anti fish farm activists and some First Nations have been calling for the end of salmon farming in B.C. for well over a decade.

The scientific evidence to back up their warnings that salmon farms pose a threat to wild salmon has been scant.

But now the Pacific Salmon Foundation is adding its voice to the call to phase out open-net salmon farms, and a new study by Canadian scientists suggests disease from salmon farms may, in fact, pose a risk to wild stocks.

Last week, the PSF took a stance on the issue, calling on the federal and B.C. governments to shut down open net fish farms and move them closed containment systems.

“The Pacific Salmon Foundation (PSF) believes that British Columbia and Canada must put wild Pacific salmon first and that a move to closed-containment salmon aquaculture is recommended,” the foundation’s board of directors state in a press release.

“We are taking this position now based on the combination of the information in the recent report of the Ministerial Advisory Committee on Finfish Aquaculture; the results of our own research to date; and the chronically-low abundance of most wild Pacific salmon populations today.”

The position comes at a time when the NDP government is reviewing the recommendations of the Minister of Agriculture's Advisory Council on Finfish Aquaculture.

“We’re disappointed in what the Pacific Salmon Foundation has said,” said Shawn Hall, a spokesperson for the BC Salmon Farmers Association (BCSFA).

“We’re currently actively involved in research projects with them into the health of wild salmon, and that work’s not complete. So they’ve come out with a verdict before that research work is done.”

The main concern over salmon farms is the fear that diseases and parasites from open net salmon farms could transmit to wild salmon.

Last year, the Monterey Bay Aquarium’s Seafood Watch bumped the B.C. salmon farming industry’s sustainability rating up from red to yellow, which means it is a “good alternative” to other seafood that may not be as sustainably harvested or produced.

Sea Watch reviewed all the available peer-reviewed literature on salmon diseases, and concluded: “Although a level of concern is warranted, there is currently no evidence that there is any impact from salmon farms to wild salmon. Importantly, there is also no evidence that there is no impact.”

But a new study published by a team of scientists with the Strategic Salmon Health Initiative (SSHI) has now drawn a direct link between a virus found in Atlantic farmed fish – piscine reovirus (PRV) – and two related diseases.

The SSHI project, led by scientist Kristi Miller, is a joint effort between Fisheries and Oceans Canada, Genome BC and the PSF.

The new study – the third so far in a series – builds on an earlier one that found a statistical correlation between PRV and a disease called HSMI (heart, skeletal and muscle inflation), but which did not establish a causal link.

The latest study is more definitive, stating that PRV is a “causative” agent of HSMI in Atlantic salmon. It also concludes that PRV causes a similar disease, as well as jaundice and anemia, in Chinook salmon.

“Viral genome sequencing revealed no consistent differences in PRV-1 variants intimately involved in the development of both diseases, suggesting that migratory Chinook salmon may be at more than a minimal risk of disease from exposure to the high levels of PRV occurring on salmon farms,” the study states.

Brian Riddell, a former DFO scientist and current CEO of the Pacific Salmon Foundation, confirmed that the PSF’s recent position on salmon farming was prompted in part by the SSHI’s recent findings.

“The results of this study are significant because they show – for the first time – strong evidence that the same strain of PRV that causes heart and skeletal muscle inflammation disease (HSMI) in Atlantic salmon is likely to cause disease in at least one species of Pacific salmon,” Riddell said in a press release.

Greg Taylor, a fisheries adviser for Skeena Wild Conservation Trust and Watershed Watch, isn’t convinced that fish farms are the biggest threat to wild salmon. But it’s the one threat that can be removed, he said, so he supports the PSF’s position.

“I still don’t think they are the largest threat relative to habitat loss, climate change, too much hatchery produced fish in the North Pacific, pinniped predation, overfishing, etc.,” Taylor told Business in Vancouver.

“But, they are a significant controllable risk factor. I think this new science adds to the weight of evidence against this industry.”

The PSF is calling for the industry to transition from open-net pens to land-based systems.

“This transition to closed containment will take time but the removal of open net-pen farms along migratory routes of wild Pacific salmon, particularly for those stocks of greatest concern, should occur as soon as possible,” the PSF recommends.

For all intents and purposes, however, that would likely mean the end of salmon farming in B.C., since land-based fish farms have proven uneconomic.

After more than two decades of trying, no land-based salmon farm project has yet been able to turn a profit in B.C. The only one in B.C. that has come close – Kuterra – was developed with significant government subsidies.

The federal government covered roughly half of the $15 million invested in the project, and the Namgis First Nation also subsidized the fish farm until it decided it could no longer afford to do so.

Last year the Namgis signaled it wanted to either sell Kuterra or find other investors. A Kuterra spokesperson confirmed that it now has one private investor that may be interested in taking a stake in the project. Meanwhile, Kuterra is planning to produce one last harvest in June before shutting down for a year for maintenance.

Hall said the PSF’s recommendations for moving all open-net salmon farms to closed containment are not realistic.

“Saying that we should just move all salmon farms to closed containment on land makes a good sound bite, but it’s not viable,” Hall said. “It would effectively shut the industry down.”

Salmon farming in B.C. is a $1.5 billion industry that employs about 6,600 people.

nbennett@biv.com

@nbennett_biv