A recent study by the Pacific Salmon Foundation reveals that viral heart disease, specifically heart and skeletal muscle inflammation (HSMI), is more prevalent in open-net salmon farms in British Columbia’s Broughton Archipelago than previously acknowledged. The study, published in the journal Aquaculture, identified HSMI in five out of seven open-net pen salmon farms in the region. The virus responsible for the disease, piscine orthoreovirus (PRV), was found to have the potential to spread to wild fish in the surrounding waters.
Lead author Emiliano Di Cicco emphasized that the incidence of the disease is higher than previously believed based on their research findings. While previous studies in 2017 indicated HSMI in only one out of four farms, the current study demonstrates a more widespread presence of the disease.
The Department of Fisheries and Oceans (DFO) has been urged to reclassify PRV as a pathogenic virus, as it can lead to anemia, inflamed hearts, damaged organs, and jaundice in Pacific salmon. Di Cicco also highlighted the need for standardized diagnostic criteria for HSMI to align with global standards, as differing criteria may result in underdiagnosis of the disease.
DFO has acknowledged the study and stated that detecting a virus in farmed fish does not automatically imply adverse effects on wild salmon populations. The agency emphasized that its diagnostic criteria for HSMI have been developed in collaboration with scientific experts to ensure scientific rigor and alignment with international standards.
The study was conducted in collaboration with the Mamalilikulla, ʼNa̱mǥis, and Ḵwiḵwa̱sut’inux̱w Ha̱xwa’mis First Nations. Indigenous leaders from these communities have expressed concerns about the impact of open-net pen salmon farms on wild salmon populations and the environment, emphasizing the cultural and ecological significance of salmon to their communities.