Scientists dispute findings of provincial report that minimizes risk of aquaculture to wild salmon
A group of scientists is challenging a B.C. government report that plays down the risks of aquaculture to wild Pacific salmon.
In a written critique, the scientists say the report by Gary Marty, a fish pathologist at the provincial Animal Health Centre in Abbotsford, leads to a biased conclusion that farmed salmon pose minimal disease risks to wild salmon in B.C.
“A more complete and balanced assessment of the scientific literature reveals abundant evidence that salmon aquaculture does pose a disease risk to wild salmon, although there is ongoing debate about the extent of that risk,” the critique states.
The eight scientists — from B.C., Alberta, and Ontario and specializing in salmon and infectious diseases — are concerned the report could be used by the province to justify an expansion of salmon farming on the coast.
In response, Agriculture Minister Norm Letnick said in a written statement Friday he is “confident that Dr. Marty is able to present scientific evidence on this issue in an unbiased and professional manner with due consideration of all information; indeed, this is a requirement of his position and professional accreditation.”
Letnick said that Marty is playing a role in ongoing research on fish health to “increase our understanding of possible interactions between salmon aquaculture and wild populations.” Salmon farm applications are subject to extensive review by federal and provincial governments, he said, adding B.C. is committed to the responsible management of fisheries, including a sustainable aquaculture industry.
Marty’s report, dated March 16, 2015, is entitled, Information Regarding Concerns about Farmed Salmon – Wild Salmon Interactions.
He concludes that diseases in B.C. farmed Atlantic salmon “pose no more than a minimal risk of serious harm to the health of migrating wild salmon” and that less than one per cent of Atlantic salmon die of diseases that might be infectious to wild Pacific salmon.
Among the other 99 per cent of farmed salmon, 90 per cent survive and nine per cent die of other causes.
Marty added the escape of farmed salmon also poses minimal risks, noting there have been 170 deliberate releases of Atlantic salmon over the years in North American waters in attempts to establish reproducing populations, and all failed.
Four of the researchers who signed the critique are with Simon Fraser University: Lawrence Dill, professor emeritus, department of biological sciences; Brendan Connors, senior systems ecologist, ESSA Technologies, and adjunct professor, department of biological sciences; Richard Routledge, professor, department of statistics and actuarial science; and John Reynolds, professor and Tom Buell B.C. Leadership Chair in Aquatic Conservation, department of biological sciences.
In an interview, Dill said there is research ongoing, including by the federal fisheries department and Pacific Salmon Foundation, to establish the disease risk that Atlantic salmon pose to wild Pacific salmon and that it is premature to conclude the risk is minimal. He urged the province not to approve any expansion of salmon farming until those studies have been concluded, perhaps in two or three years.
There is “considerable evidence, both in B.C. and otherwise, that sea lice, for example, have a major effect on wild fish,” said Dill, adding that the cause of death of most fish in fish farms is not determined.
He added that the scientists have written to Premier Christy Clark and three of her cabinet ministers but none have responded.
Marty is on holidays but emailed The Sun to say that he is working on a detailed response to the critique that won’t be ready until July.
He noted that his report was a brief summary for a general audience and not a comprehensive literature review for a peer-reviewed scientific journal.
He agreed with the scientists that his report “incorrectly states a secondary conclusion of one scientific paper” but emphasized that “does not alter my conclusion that diseases in B.C. farmed Atlantic salmon pose no more than a minimal risk of serious harm to the health of migrating wild salmon.”
He said his conclusions are based on more than two decades of diagnostic veterinary pathology on thousands of wild and farmed salmon and trout, and that his report contained “606 reasons that informed my conclusion.”
Marty added that infectious disease spreads less readily in dispersed populations such as wild salmon and that information about the cause of death for farmed salmon has been routinely reported by fish farmers and reported publicly for the past decade.