A recent study by the Pacific Salmon Foundation reveals that viral heart disease, specifically heart and skeletal muscle inflammation (HSMI), is more common in open-net salmon farms in British Columbia than previously acknowledged. The research identified HSMI in five out of seven open-net pen salmon farms located in the Broughton Archipelago, near Vancouver Island. The study also highlights the potential transmission of the disease-causing virus, piscine orthoreovirus (PRV), to wild fish in the surrounding waters.
Lead author Emiliano Di Cicco emphasized that the prevalence of the disease is higher than previously believed. Previous research conducted in 2017 found HSMI in one out of four farms, indicating a more widespread issue. The study detected HSMI in nearly seven percent of the 749 salmon examined by independent pathologists across the farms.
While the role of PRV in causing HSMI was once uncertain, recent experiments by Norwegian researchers confirmed the link in 2017. The virus can lead to various health issues in Pacific salmon, including anemia, heart inflammation, liver and kidney damage, and jaundice. Di Cicco urged the Department of Fisheries and Oceans (DFO) in British Columbia to reclassify PRV as pathogenic and align disease diagnosis criteria with international standards.
DFO responded that they would review the study findings for future consideration. The agency emphasized that detecting a virus in farmed fish does not automatically imply negative impacts on wild salmon populations. The diagnostic criteria for HSMI were developed in collaboration with scientific experts to ensure scientific rigor and global alignment.
The study was conducted in collaboration with the Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis First Nations. Indigenous leaders expressed concerns about the impact of open-net pen salmon farms on salmon populations, highlighting the cultural and ecological significance of salmon to their communities. They stressed the importance of supporting salmon for the well-being of both the ecosystem and Indigenous peoples in British Columbia.