Activist-Linked Study Manufactures Salmon Farming Scare in British Columbia

A bacterial disease found in captive Chinook is being used to implicate ocean salmon farms, despite no proof of a marine aquaculture source or harm to wild populations.

Analysis
Fabian Dawson
SeaWestNews

Another activist-linked study has arrived loaded with “could” and “may” warnings, to stoke fear and steer the public toward a salmon farming connection the research couldn’t prove.

The study was released by the Pacific Salmon Foundation (PSF), whose opposition to marine salmon aquaculture mirrors the position advanced by anti-fish farming campaigners in British Columbia.

It adds to a growing collection of PSF-linked findings that critics say have exaggerated theoretical risks, blurred the line between pathogen detection and disease, and been challenged by fish pathologists, veterinarians and government science reviews.

The latest paper reports that Tenacibaculum dicentrarchi, a naturally occurring marine bacterium found in coastal waters, was linked to disease in wild-caught, captive Chinook salmon during an unrelated catch-and-release study.

It does not show the bacteria came from a salmon farm.

It does not document transmission from farmed Atlantic salmon.

And it does not demonstrate any population-level impact on wild salmon.

The authors also admit the disease may have taken hold because the fishes’ protective mucus coating, which helps guard against infection, may have been damaged during the study.

Yet the PSF media release surrounds a narrow finding of bacterial disease in handled and captive Chinook with references to ocean salmon farms and federal disease assessments, manufacturing a link the study failed to prove.

The study comes as Ottawa weighs whether to proceed with an activist-induced Trudeau-era policy that would remove marine salmon farms from British Columbia waters after June 2029.

That decision threatens thousands of jobs, more than $1 billion in annual economic activity and agreements between salmon farming companies and coastal First Nations.

The PSF study follows a detailed critique of an earlier study used to portray Tenacibaculum as a major farm-related threat to wild salmon  by veteran fish pathologist Dr. Gary Marty, a research associate with the UC Davis School of Veterinary Medicine.

That 2022 paper, involving researchers connected to the Pacific Salmon Foundation, estimated that exposure to farm-origin T. maritimum could kill between 6.5 and 56.1 per cent of migrating Fraser River sockeye smolts.

The estimate generated alarming headlines and became part of the case advanced against salmon farming.

Dr. Marty found the mortality claim rested largely on mathematical modelling and laboratory PCR detections, which can identify traces of bacterial genetic material but cannot, on their own, prove a fish was infected, became sick or died from the organism.

He examined related data from the same research group and found that 52 of 2,280 sockeye initially tested positive. After applying detection limits and accounting for potential false positives, only three fish remained confidently PCR-positive.

Dr. Marty’s broader peer-reviewed review of more than  two decades of real-world data concluded there is no good evidence that pathogens from B.C. salmon farms have caused long-term declines in wild Pacific salmon populations.

It found that removing marine salmon farms would be unlikely to produce any measurable improvement in wild salmon productivity. That conclusion aligns with repeated federal science assessments finding no more than minimal population-level risk from the farms.

This is not the first time a limited pathogen finding has been inflated into a warning about salmon farming.

Earlier laboratory work examined whether T. maritimum could transfer to coho through prolonged cohabitation with farmed Atlantic salmon.

About 80 coho were exposed. Only four showed disease signs, and those fish were already in poor condition.

Joseph Nowlan, the researcher who led the trial, told  SeaWestNews that activists were focusing on the few fish that became sick while ignoring the overwhelming majority that remained healthy.

“The presence of the bacteria isn’t an absolute indicator of whether an animal is susceptible to disease,” he said.

Similar criticism has followed PSF-linked research that used molecular detections to claim increased infection risks near salmon farms.

The recurring pattern is clear.

A bacterium is detected.

A theoretical risk is raised.

Ocean salmon farms are inserted into the media release.

The gaps between exposure, disease, source and population harm are left for the public to overlook.

This new PSF study makes a useful contribution to fish pathology. The findings should prompt further work into natural exposure, handling stress, disease development and transmission in free-swimming fish.

Instead, the PSF places ocean salmon farms at the centre of its public narrative without identifying a farm source.

It is yet another example of activist ideology grafted onto a limited scientific finding and injected into the political debate over salmon farming,   where fear has too often outrun the facts.

Main image shows a Chinook salmon caught in the Barkley Sound for research. Photo: UBC Forestry & Environmental Stewardship’s Pacific Salmon Ecology and Conservation Lab