A recent study by the Pacific Salmon Foundation reveals a higher prevalence of viral heart disease in open-net salmon farms in British Columbia than previously acknowledged. The research, published in the journal Aquaculture, identified heart and skeletal muscle inflammation (HSMI) in five out of seven open-net pen salmon farms in the Broughton Archipelago. The study also highlights that the disease-causing virus, piscine orthoreovirus (PRV), can spread to wild fish in the surrounding waters.
Lead author Emiliano Di Cicco emphasized that the occurrence of the disease is more significant than previously believed. Previous research in 2017 found HSMI in one out of four farms, indicating a recurring issue rather than an isolated case.
The Department of Fisheries and Oceans (DFO) will assess the study’s findings for future consideration. The study discovered symptoms of HSMI in nearly seven percent of the 749 examined salmon, suggesting a notable impact on the fish population.
While the DFO currently categorizes PRV as non-pathogenic, Di Cicco urges the reclassification of the virus as pathogenic and alignment of diagnostic criteria with global standards. He argues that the disease is a chronic, low-level condition, requiring a broader approach to diagnosis beyond observable symptoms or significant mortality spikes.
Collaborating with First Nations communities, the study underscores the importance of supporting salmon populations, particularly for coastal Indigenous groups in British Columbia. Leaders from these communities express long-standing concerns about the impact of open-net pen salmon farms on wild salmon populations and the ecosystem, advocating for stronger conservation measures.