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, identified HSMI in five of seven open-net pen salmon farms located in the Broughton Archipelago near Vancouver Island.
The study highlights that the disease-causing virus, piscine orthoreovirus (PRV), can transmit to wild fish through the surrounding waters. Lead author Emiliano Di Cicco emphasized that the incidence of the disease is significantly higher than initially believed, challenging previous assumptions.
The research, which involved examining 749 salmon across various farms, found that nearly seven percent of the fish displayed signs of HSMI. While there was uncertainty regarding the role of PRV in causing HSMI a decade ago, recent experiments by Norwegian researchers have established a definitive link.
Symptoms of PRV infection in Pacific salmon include anemia, inflamed hearts, liver and kidney damage, and jaundice. Di Cicco is urging the Department of Fisheries and Oceans (DFO) in British Columbia to reclassify PRV as pathogenic and align diagnostic criteria for HSMI with global standards.
DFO responded, stating they would review the study and incorporate its findings into future assessments. The agency emphasized that the diagnostic criteria for HSMI were developed in collaboration with scientific experts to ensure scientific rigor and alignment with global standards.
The study was conducted in collaboration with the Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis First Nations. Indigenous leaders expressed gratitude for the scientific validation of their concerns about the impact of open-net salmon farms on wild salmon populations, emphasizing the cultural and ecological significance of salmon to their communities.
