A Simon Fraser University fish-population statistician and a fisheries biologist at the Watershed Watch Salmon Society said they found evidence of the piscine reovirus (PRV) in cutthroat trout caught in Cultus Lake, in the Fraser Valley region of the province.
Analysis of the virus identified its genetic sequencing as 99 percent identical to strains that are widespread in Norwegian salmon farms and can kill up to 20 percent of infected fish.
The discovery of PRV in freshwater sport fish indicates the virus could be prevalent in British Columbia, researchers say.
"If PRV has been found in a Cultus Lake sport fish it could be contributing to the failure of the lake's sockeye population to return in abundance," SFU Professor Rick Routledge said.
PRV is the second virus commonly associated with salmon farming that scientists have found in wild Pacific salmon and trout, a Simon Fraser release said Thursday.
Researchers in many countries have raised concerns about the spread of PRV from farms to wild salmon.