A recent study by the Pacific Salmon Foundation has revealed 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 study, published in the journal Aquaculture, identified HSMI in five out of seven open-net pen salmon farms located in the Broughton Archipelago near Vancouver Island.
Researchers highlighted that the disease-causing virus, piscine orthoreovirus (PRV), has the potential to spread into the surrounding waters and infect wild fish. Lead author Emiliano Di Cicco emphasized that the incidence of HSMI is significantly higher than previously believed based on their findings.
The study involved examining 749 salmon across the farms, with nearly seven percent displaying signs of HSMI. While the role of PRV in causing HSMI was uncertain a decade ago, recent experiments by Norwegian researchers have firmly established the link, according to Di Cicco.
Affected Pacific salmon can experience anemia, inflamed hearts, damaged livers and kidneys, and jaundice when infected with PRV. Di Cicco urged the Department of Fisheries and Oceans (DFO) in British Columbia to reclassify the virus as pathogenic, aligning with global standards for diagnosing the disease.
DFO stated it would review the study and consider its implications for future actions. The B.C. Salmon Farmers Association, when approached for comment, did not respond immediately. However, the industry group has previously downplayed concerns regarding PRV, labeling them as “fearmongering” and stating that the virus is relatively benign and widespread.
The study was conducted in collaboration with the First Nations groups Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis, reflecting the importance of salmon to Indigenous communities in B.C. Chiefs from these nations expressed gratitude for the scientific confirmation of their long-held concerns about the impact of open-net pen salmon farms on wild salmon populations.
