Inside the work of activist-scientists associated with a government funded program that continues to alarm the public about salmon farming in British Columbia.
By Fabian Dawson
A $10 million government-backed program to study the potential effects of microbes on wild and farmed fish is being abused by scientists connected with anti-ocean aquaculture activists, to alarm the public about salmon farming in BC.
The charge made today by the BC Salmon Farmers Association (BCSFA) comes in the wake of a study released last month, which claimed that the benign PRV virus spread from aquaculture operations into wild fish.
The PRV virus was actually detected in a wild-source steelhead trout sampled in 1977 and its discovery predates salmon farming in BC.
Last month’s study orchestrated by some well-known activist-scientists was part of the Strategic Salmon Health Initiative (SSHI) established eight years ago to investigate potential relationships between variability in the survival of juvenile salmon during early ocean migration and the microbes they carry.
“The study highlights yet again the long-standing concerns of the BC salmon farming industry regarding the credibility of research supported by the SSHI,” the BCSFA said in a statement.
“Rather than contributing to a greater understanding of the factors actually impacting the health of BC’s wild salmon populations, the SSHI research team leading this 10-million dollar program (64% of which came from the Federal Government) has simply succeeded in generating alarm and uncertainty.”
A spokesperson for the Department of Fisheries and Oceans Canada (DFO) told SeaWestNews that an international panel of experts met in March 2021 to go over SSHI findings to date and discuss where the research should go moving forward.
Gideon Mordecai, a viral ecologist at the University of British Columbia (UBC), the lead author of the latest study, described the original 1977 detection of PRV in a wild-source steelhead trout as “suspect”.
“These detections are considered putative findings only, and to validate them, a peer-reviewed study would need to sequence archival PRV from 1977 and should include sufficient controls to screen out contaminants,” he told SeaWestNews.
“I also highlight that the genomic epidemiological investigation found evidence for more than one introduction of PRV from Europe to BC.”
BCSFA in their statement today said the authors defend their dismissal of the 1977 positive test by stating that it has not been verified by genetic sequencing. However, in May 2020, researchers at Fisheries and Oceans Canada repeated the positive PRV test in the 1977 sample through sequencing (GenBank).
“Given that one of the lead authors of the study also works at Fisheries Oceans Canada, it is surprising that this researcher was not aware that the positive test had in fact been repeated.
“If this sequenced positive test result is a true positive, then PRV was in BC waters prior to the introduction of Atlantic salmon farming.”
The BCSFA is recommending that the authors submit a correction to Science Advances, where the study was published.
According to consensus by a broad range of fisheries scientists, which debunks the latest study, PRV has long been present in wild salmon in Pacific Northwest waters and all experimental exposures of the BC strain of PRV to Pacific and Atlantic salmon in BC have failed to induce disease or mortality.
Dr. Hugh Mitchell, an aquaculture veterinarian, with more than 30 years of experience, agreed that the latest paper has more to do with activism against fish farms than science.
In a Twitter post, Mitchell states: “First, PRV was found in 1977 AND sequenced from wild-source BC steelhead trout pre-dating Atlantic salmon PNW (Pacific North West) culture. Allegations of being introduced by farmed Atlantic salmon are false.”
“What is disturbing is that the paper’s authors are an isolated group (not representative of the entire Canadian Department of Fisheries and Oceans) who continually focus on activist research against aquaculture and ignore contradicting evidence,” he said.
Another conclusion in the latest study that “evidence strongly supports Atlantic salmon aquaculture as a source of infection in wild Pacific salmon” has also been challenged by the BCSFA.
“To indirectly assess transmission from farmed to wild salmon, the authors state that they investigated the probability of PRV infection for wild Chinook salmon in relation to distance from active aquaculture facilities – and found that PRV-1 infection was closely tied to farm proximity,” said the BCSFA.
“However, by their own admission, the authors did not take account of other factors that might influence PRV-1 prevalence (e.g. different environmental conditions or differences in host condition between regions). Without accounting for the significance of these factors, how could the authors arrive at their conclusion?”
The BCSFA said the study authors strive to provide support for their conclusion by citing three studies which they say also implicate PRV-1 transmission from farmed Atlantic salmon to wild salmon.
“However, one of the three cited studies has since been corrected – and these corrections make its original conclusions invalid. Another of the studies considered farm-to-farm transmission (i.e. not farmed-to-wild transmission), while the third was unable to establish a clear line of transmission from farmed to wild salmon.
“In an effort to bolster their own questionable conclusion, the authors of the study thus appear to have adopted rather lax citation standards,” said BCSFA.
“Furthermore, any study considering the transmission dynamics between farmed and wild salmon should recognize that all young farmed Atlantic salmon entering the marine environment have been verified PRV-free.
“In other words, farmed Atlantic salmon do not introduce PRV to the marine environment. Rather, they acquire it during their ocean residency.”
A third component of the controversial study claims PRV-1 is now an important infectious agent in critically endangered wild Pacific salmon populations, fueled by aquaculture transmission.
“As a board-certified veterinary pathologist, I disagree with the conclusion that PRV is now an important infectious agent in critically endangered wild Pacific salmon populations,” said Dr. Gary Marty, a veteran fish pathologist with the Animal Health Centre of BC’s Ministry of Agriculture, Food, and Fisheries.
“PRV is a minor infectious agent that occurs in a small proportion of wild Pacific salmon,” Dr. Marty told SeaWestNews.
“Even the thesis cited by the new paper reports only mild PRV-associated microscopic lesions among six of nine wild Chinook salmon examined. The other three fish had no PRV-associated microscopic lesions.
“Mild microscopic lesions are not a threat to wild salmon populations. Instead, mild lesions are part of the normal inflammatory response to infectious agents that wild fish encounter during their migrations,” he said.
The BCSFA said the recent SSHI-backed study is the latest in a series of publications that base conclusions on speculation.
“In a 2017 study, a research group, with clear connections to anti-salmon farming activists, suggested that wild stocks exposed to marine aquaculture sites have much higher rates of PRV infection.
Response to this study by their scientific peers required that they post a correction that rendered the claims made in the original report invalid.
In 2011, this same activist-linked research group published a report entitled Lethal Atlantic virus found in Pacific salmon.
Following this report, Canadian federal and provincial authorities undertook a broad virus surveillance program – and were unable to confirm the report’s claims.
In the aftermath of this issue, then Minister of Fisheries and Oceans Canada, Keith Ashfield, stated “because some have chosen to draw conclusions based on unconfirmed information, this has resulted in British Columbia’s fishing industry and Canada’s reputation being put at risk needlessly.”
The research group was also warned by both the BC Government and Fisheries and Oceans Canada that reckless allegations based on incomplete science can be devastating and unfair to the families that make a living from the sea.
Dr. Ian Gardner, former Canada Excellence Research Chair in Aquatic Epidemiology, who was part of the Strategic Salmon Health Initiative (SSHI) has described the group’s PRV studies as making “broad sweeping statements not supported by strong evidence.”
DFO said the SSHI initiative was to consist of four phases. The first two phases of this initiative were to focus on the identification of microbes currently carried by BC’s wild and farmed salmon – while the latter phases were to investigate the potential effects of identified microbes on the wild and farmed fish. However, the final two phases were never completed.
“As a result of the researchers’ inability to complete their stated task, their publications have largely focused on viral discovery; they have failed to publish any scientific studies that investigate whether the viruses they discovered are actually threatening wild or farmed stocks,” said BCSFA.
Dr. Kenneth Warheit, fish health and genetic specialist for the Washington Department of Fish and Wildlife, said there is not a single study to support the claim by anti-salmon farming activists that PRV from open-water pens will harm wild fish.
“These activist scientists opposed to marine aquaculture have hijacked the study process to confuse the public about salmon farming,” said an aquaculture veteran.
“First they created the falsehood that salmon farming is bad for wild fish, now they are creating the science to back that claim,” he told SeaWestNews.
(File image shows a salmon smolt)