A Deadly Virus: Piscine Orthoreovirus (PRV)
In a recent study, Department of Fisheries and Oceans scientist, Dr. Kristi Miller, found that migratory Chinook salmon are at risk of disease from exposure to the high levels of piscine orthoreovirus (PRV) occurring on salmon farms. PRV causes red blood cells in Chinook salmon to rupture, spreading toxins that damage the kidney and liver, weakening the wild salmon.
Early in 2019, Canada’s Federal Court overturned the Department of Fisheries and Oceans (DFO) policy permitting fish farms to transfer salmon farm hatchery smolts to ocean net pens without screening for PRV. Justice Cecily Strickland ruled that DFO is failing to consider the health of wild salmon and violating the Fisheries Act by not meeting “the precautionary principle” for protection. Strickland gave DFO four months to undertake a risk assessment and come up with a new policy to ensure that farmed salmon are not transferring PRV to wild salmon. At the deadline on June 4, Jonathan Wilkinson, the Minister of Fisheries and Oceans, announced that DFO will finally require testing PRV for all salmon farms.
Currently there are 130 salmon farms in B.C. with 20 located in Clayoquot Sound. But salmon farms are not the only possible source of PRV transmission. After inspecting the fish processing plants in 2018, the B.C. Ministry of Environment’s laboratory results confirmed the presence of PRV. Of the 109 fish processing plants in B.C., 28 have provincial permits under B.C.’s Environmental Management Act to release “bloodwater” effluent into ocean waters, including Lions Gate in Tofino.
