A recent study by the Pacific Salmon Foundation reveals that viral heart disease, specifically heart and skeletal muscle inflammation (HSMI), is more prevalent in open-net salmon farms in British Columbia than previously acknowledged. The research, published in the Aquaculture journal, identified HSMI in five out of seven open-net pen salmon farms located in the Broughton Archipelago near Vancouver Island.
The study highlights the presence of the disease-causing virus, piscine orthoreovirus (PRV), which has the potential to spread to wild fish in the surrounding waters. Lead author Emiliano Di Cicco emphasized that the incidence of the disease is significantly higher than previously believed.
This finding underscores the ongoing debate surrounding open-net fish farms off the coast of British Columbia, particularly regarding the risk of disease transmission from farmed fish to wild salmon populations. The study, which involved examining 749 salmon across multiple farms, revealed that nearly seven percent exhibited signs of HSMI.
While the role of PRV in causing HSMI was once uncertain, recent experiments by Norwegian researchers have established a clear link. The disease can lead to various health issues in Pacific salmon, including anemia, inflamed hearts, and damaged organs.
Di Cicco is urging the Canadian government, specifically the Department of Fisheries and Oceans (DFO), to reclassify PRV as pathogenic due to its impact on fish health. He also advocates for aligning diagnostic criteria for HSMI with international standards, as current methods may overlook the disease’s prevalence.
In response to the study, DFO stated that it will evaluate the findings and incorporate them into future research efforts. The agency emphasized that its diagnostic criteria for HSMI were developed in collaboration with scientific experts to ensure alignment with global standards.
The B.C. Salmon Farmers Association has yet to comment on the study’s findings. The organization has previously dismissed concerns about PRV as “fearmongering,” describing the virus as common and benign in marine environments. Industry groups argue that salmon farming in British Columbia plays a crucial role in the economy, providing jobs and accounting for the majority of Canada’s salmon production.
The study was conducted in partnership with several First Nations groups, including Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis. Indigenous leaders expressed gratitude for the scientific validation of their concerns regarding the impact of salmon farming on wild populations, emphasizing the cultural significance of salmon in their communities.