Internal tools used by Fisheries and Oceans Canada (DFO) to determine if infectious agents should be regulated as diseases are scientifically flawed and overlook threats to wild fish populations, according to a new, peer-reviewed evaluation by a UBC Institute for the Oceans and Fisheries (IOF) researcher.
The perspective article assessed the internal tools used by DFO to assess whether two infectious agents commonly found on salmon farms, Piscine orthoreovirus (PRV) and Tenacibaculum maritimum, are deemed pathogenic and therefore must be regulated as ‘disease agents’. The analysis by Dr. Gideon Mordecai, research associate in IOF, raises doubt over the suitability of DFO’s disease assessment forms to reliably inform decision making. It identifies key flaws that led DFO to conclude that T. maritimum is unlikely to cause disease in wild fish, and that PRV is not an infectious disease agent – despite credible scientific evidence to the contrary.
“DFO has long faced criticism for disregarding scientific evidence on the disease risks that open-net pen aquaculture poses to wild salmon. This paper exposes the mechanics behind that failure ¬– revealing how their disease assessment framework consistently downplays or ignores credible science.” says Dr. Mordecai. “The assessments cite a lack of evidence of disease impacts, while omitting a large body of evidence which links these pathogens to disease in Pacific salmon. As a result, the forms incorrectly conclude that these pathogens are unlikely to cause disease in wild fish populations.”
The study also highlights significant transparency concerns. Although the disease assessment forms are described by DFO as “public documents”, up-to-date versions of the forms are not readily made available for public scrutiny. Internal government communications obtained through access to information requests reveal that decisions about whether to release these forms were influenced by the anticipated criticism and critique from conservation organisations.
“Science and good policy rely on scrutiny. If assessments that determine disease risks to wild fish are being withheld to avoid public or expert feedback, then that undermines trust and the credibility of the entire process,” said Dr. Mordecai. “It is precisely that criticism and critique which ensures accuracy. My hope is that DFO will release up-to-date versions of these forms to their public website, so that scientific oversights can be corrected and recent research properly incorporated.”
Image by Kevin Phillips from Pixabay
“To put the health of wild Pacific salmon first, we need a regulatory system grounded in credible, transparent science,” says Dr. William Bugg, a postdoctoral scientist with the Pacific Salmon Foundation, who was not involved with the analysis. “Through more than a decade of research on potential pathogen transmission from farmed to wild salmon in British Columbia, we’ve published dozens of peer-reviewed papers linking open-net pen Atlantic salmon farms to risks for wild salmon populations. This research should be at the forefront of decision-making processes.”
On Monday, September 29, 2025, the First Nations Wild Salmon Alliance held a media conference to put pressure on the Federal government to finish the Open Net Pen Transition Planning process. Dr. Mordecai participated as a panel member, and described ongoing issues with the quality of the science advice regarding fish farm associated pathogens. He recommended establishing an Independent Fisheries Science Advisory Body, insulated from political and industry pressures, to ensure that the transition plan is informed by robust science advice moving forward. A full version of the presentation is now available.
Canada’s framework for assessing the pathogenicity of infectious agents within fisheries and aquaculture was published in FACETS.
- Op-ed by Dr. Mordecai: Opinion: DFO’s flawed science leaves wild salmon vulnerable to disease, Vancouver Sun, September 29, 2025
- B.C. First Nations want meeting with Carney about salmon, need for open-net farm ban. CTV News, September 29, 2025
Tags: Aboriginal fisheries, Chinook salmon, First Nations Wild Salmon Alliance, fish farms, Fisheries and Oceans Canada, Gideon Mordecai, Indigenous fisheries, IOF Research Associates, Pacific Ocean, Pacific Salmon Foundation, Piscine orthoreovirus (PRV), salmon, salmon lice, viruses