A recent study by the Pacific Salmon Foundation reveals that viral heart disease, known as 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, detected HSMI in five out of seven open-net pen salmon farms located in the Broughton Archipelago near Vancouver Island’s Port McNeill.
The study also highlighted the potential spread of the disease-causing virus, piscine orthoreovirus (PRV), from farmed fish to wild populations in the surrounding waters. Lead author Emiliano Di Cicco emphasized that the incidence of the disease is significantly higher than initially believed, challenging past assumptions.
The debate surrounding open-net fish farms off British Columbia’s coast has been ongoing, with concerns about disease transmission to wild salmon. Previous research by Di Cicco and colleagues in 2017 identified the disease in one out of four farms, indicating a broader issue than initially recognized.
The study involved examining 749 salmon, of which nearly seven percent displayed signs of HSMI, suggesting a significant prevalence of the disease. While the role of PRV in causing HSMI was previously uncertain, recent experiments by Norwegian researchers established the link, prompting calls for its reclassification as a pathogenic virus by the Department of Fisheries and Oceans (DFO).
Di Cicco urged for standardized diagnostic criteria for HSMI, emphasizing the chronic nature of the disease globally compared to current diagnostic practices in Canada. The DFO responded, stating they would review the study findings and incorporate them into future assessments, highlighting the rigorous scientific collaboration in establishing diagnostic guidelines.
The collaboration with First Nations communities, including Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis, underscores the shared concern for salmon health and ecosystem well-being. Indigenous leaders, such as Rick Johnson and Don Svanik, expressed gratitude for the scientific validation of their long-held beliefs regarding the impact of open-net pen salmon farms on wild salmon populations and emphasized the cultural significance of salmon to their communities.
