Attempt to Detect a Salmon Viral Pathogen from Seawater Collected in British Columbia

Wild Pacific salmon populations are subject to multiple anthropogenic stressors leading to marked declines in British Columbia. One important stressor may be disease, and disease linkages between Atlantic salmon aquaculture and wild Pacific salmon populations. Macroparasite transmission between farmed Atlantic salmon and wild Pacific salmon has been studied extensively in British Columbia. The potential for viral transmission and the abundance of viral pathogens in the marine environment has not been rigorously assessed. We collected water samples from 62 fish farm sites in B.C., where roughly half were active farms and half were inactive. Presence of the salmon viral pathogen piscine reovirus (PRV) was analyzed using quantitative PCR. PCR detection of common picorna-like virus was used to test for amplifiable material. Ultimately, the methods failed to detect PRV, most likely due to sample degradation linked to the relative instability of RNA.M.Sc