Piscine Orthoreovirus (PRV) is a highly contagious virus affecting salmon in BC. A new study, published May 26, 2021, from the University of British Columbia, the Department of Fisheries and Oceans, GenomeBC and Pacific Salmon Foundation shows PRV (piscine orthoreovirus) arrived in BC at the same time as industrial fish farming. It confirms that, during their time in open net pen fish farms, nearly all farmed salmon are infected with PRV.
The study also confirms that endangered wild Chinook salmon from areas near the farms are far more likely to pick up the infection than Chinook in areas without farms. In Chinook salmon, the virus causes kidney and liver damage that can be fatal.
In Norway, PRV has been linked to Heart and Skeletal Muscle Inflammation (HSMI), which causes problems with the heart, liver, spleen, and other internal organs in salmon. HSMI has a mortality rate of 20%. It is a deadly disease that can quickly devastate a salmon population.
PRV is extremely contagious. 95% of farmed salmon in BC test positive for PRV. The dense nature of open net pen fish farms allows PRV to mutate to higher levels of virulence. Most concerning, PRV can be spread through water, making wild Pacific salmon who come in close proximity to open net pen fish farms highly susceptible to the virus. PRV is a powerful example of what happens when viruses are left to replicate in open net pen fish farms.