A recent study by the Pacific Salmon Foundation revealed that viral heart disease, known as heart and skeletal muscle inflammation (HSMI), is more prevalent in open-net salmon farms in British Columbia than initially acknowledged. The research identified HSMI in five out of seven open-net pen salmon farms located in the Broughton Archipelago, east of Port McNeill on Vancouver Island. The study also highlighted the potential of the disease-causing virus, piscine orthoreovirus (PRV), 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 assumed. This study builds upon their 2017 research, which initially detected the disease in one out of four farms. The findings challenge the existing classification of PRV as non-pathogenic by the Department of Fisheries and Oceans (DFO) in British Columbia and advocate for a reevaluation of its pathogenic status.
The study found that nearly seven percent of the 749 examined salmon showed signs of HSMI, indicating the widespread impact of the disease. While DFO is reviewing the study’s implications, researchers urge for a reassessment of diagnostic criteria for HSMI to align with global standards. The study underscores the need for a more comprehensive approach to disease surveillance in open-net fish farms to protect both farmed and wild salmon populations.
Collaborating with the Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis First Nations, the study underscores the importance of supporting salmon populations, which have historically sustained coastal Indigenous communities in British Columbia. First Nations leaders express concerns over the environmental impact of open-net salmon farms and advocate for their closure to safeguard the ecosystem and preserve cultural heritage.
The study’s findings shed light on the complex relationship between aquaculture practices and wild salmon populations, emphasizing the need for enhanced disease monitoring and conservation efforts to ensure the long-term sustainability of salmon ecosystems in British Columbia.