The Professors’ Letter and The Risks of Salmon Farming

by Ray Grigg

As the BC salmon farming industry applies to expand its operations in BC, a warning letter by eight of Canada’s leading university academics on salmon’s viral diseases and pathogens casts serious doubt on the wisdom of such an expansion.

Their letter, written to the BC government by professors from the Universities of Alberta, Toronto and Simon Fraser, is a “critique” of a March 16, 2015, paper, “Information Regarding Concerns about Farmed Salmon – Wild Salmon Interactions”, submitted by the province’s fish pathologist, Dr. Gary Marty, to Ministers Thompson and Letnik. The professors express “deep concern” that the risk to wild salmon from net-pen salmon farming is considerably greater than Dr. Marty’s estimation of minimal, and that his paper provides unjustifiable assurances concerning the safety to wild salmon.

Dr. Marty is a chief provincial advisor on matters pertaining to salmon virus and pathologies, and is an important source of the information that the salmon farming industry uses to justify its practices. When the credibility of his recommendations is questioned by such an authoritative group of critics, public concern should be roused and governments should carefully review their regulation of the industry.

In criticizing Dr. Marty’s underestimation of risk, the professors write that, “By ignoring a large body of research that contradicts many of his claims, Dr. Marty presents a biased and overly certain view of the risk posed by salmon aquaculture to wild salmon. Many studies indicate that salmon aquaculture is associated with elevated mortality of wild salmon.”

Among the faults in Dr. Marty’s methods, the professors claim, “It is illogical to draw conclusions about the effects of disease in wild salmon based solely on the effects of disease in farmed salmon. Farmed salmon do not have to migrate, avoid predators, or compete for scarce food, unlike their wild counterparts. Published scientific evidence shows that… disease also compromises their ability to grow, to compete and to avoid predators. Farm-amplified sea lice alone cause an average of 39% loss of wild salmon returning to rivers every year in Europe. …Mortality of wild salmon in British Columbia due to sea lice from farmed salmon is estimated to have been even higher in some years.”

The professors document numerous examples of Dr. Marty’s “misrepresentations or misinterpretations” of studies, and his “selective use of the published literature” to reach unfounded conclusions that minimize the “risk of disease spread from farmed salmon to wild salmon.”

Their letter is a scathing response to Dr. Marty but also, by implication, to the pro-farming position of both provincial and federal governments, to their agencies, and to the misleading assurances assiduously advanced by the industry.

To his credit, Dr. Marty has a long history of credible research and valuable contributions to the health of wild and farmed salmon. The cause of his alleged oversights, errors and faulty conclusions in this particular paper is mysterious. An obvious explanation is that policy is leading science, rather than vice versa. If such is the case, then salmon farming is putting at risk the wild salmon crucial to the West Coast marine ecology.