A recent study by the Pacific Salmon Foundation has revealed 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 out of seven open-net pen salmon farms located in the Broughton Archipelago, an island group near Vancouver Island.

The study highlights the transmission of the disease-causing virus, piscine orthoreovirus (PRV), from farmed salmon to wild fish in the surrounding waters. Lead author Emiliano Di Cicco emphasized that the occurrence of HSMI is significantly higher than previously believed, based on their findings.

Previous research in 2017 by Di Cicco and colleagues had identified the disease in one out of four farms studied at that time, indicating a broader issue than initially recognized. The study also points out the potential impact of PRV on Pacific salmon, causing anemia, inflamed hearts, liver and kidney damage, and jaundice.

Di Cicco called for the reclassification of PRV as a pathogenic virus by the Department of Fisheries and Oceans (DFO) in British Columbia, emphasizing the need for standardized diagnostic criteria aligned with global standards. While DFO stated it would review the study’s findings, the B.C. Salmon Farmers Association did not immediately respond to requests for comment.

Collaborating with local First Nations communities, the study underscores the critical role of salmon in indigenous coastal cultures and the urgent need to address the risks posed by open-net pen salmon farms to wild salmon populations and ecosystems. Leaders from the First Nations expressed gratitude for the scientific validation of their concerns and reiterated the importance of safeguarding salmon and the environment for future generations.