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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Publications at this Location » Publication #402001
Research Project: Genetic Improvement of North American Atlantic Salmon and the Eastern Oyster for Aquaculture Production

Location: National Cold Water Marine Aquaculture Center

Title: Surveillance of Piscine Orthoreovirus genotype-1 (PRV-1) in wild Pacific Salmon of British Columbia, Canada: 2011-2020

Author
item TURCOTTE, LENORA - Department Of Fisheries And Oceans Canada
item JOHNSON, STEWART - Department Of Fisheries And Oceans Canada
item BRADSHAW, JULIA - Department Of Fisheries And Oceans Canada

Submitted to: Journal of Fish Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/4/2023
Publication Date: 5/10/2023
Citation: Turcotte, L.D., Johnson, S.C., Bradshaw, J.C. 2023. Surveillance of Piscine Orthoreovirus genotype-1 (PRV-1) in wild Pacific Salmon of British Columbia, Canada: 2011-2020. Journal of Fish Diseases. https://doi.org/10.3390/fishes8050252.
DOI: https://doi.org/10.3390/fishes8050252

Interpretive Summary: To better understand PRV-1 prevalence and transmission pathways in the Northeastern Pacific Ocean, we targeted out-migrating juvenile Pacific Salmon in the Strait of Georgia and Johnstone Strait in British Columbia, Canada, for molecular screening. A total of 4,031 individuals were screened for PRV-1 and we identified an overall virus prevalence of 3.5% from 2011 to 2020. PRV-1 was absent in enhancement facilities and freshwater catchments and predominately found in the marine environment. Detections of PRV-1 varied greatly between species, year and stock of origin, but cumulatively identified that life history and migratory behaviors likely influenced viral prevalence. Specifically, Chinook salmon, which demonstrate long residence time in the Strait of Georgia relative to other species, had the highest PRV-1 prevalence in this study (7.4%). However, varying stock composition and regional detection between year classes within the Strait of Georgia indicated that main sources of infection were likely highly variable between years. These findings enhance our understanding for PRV-1 transmission in the region and more generally between/within salmon species.

Technical Abstract: Piscine orthoreovirus genotype 1 (PRV-1) is an endemic virus to the Northeastern Pacific that infects both wild and farmed salmon. To better understand PRV-1 prevalence and transmission pathways in the region, we targeted out-migrating juvenile Pacific Salmon in the Strait of Georgia and Johnstone Strait in British Columbia, Canada, for PRV-1 molecular screening with an emphasis on Chinook and Coho salmon. A total of 4,031 individuals were screened for PRV-1 and we identified an overall virus prevalence of 3.5% from 2011 to 2020. PRV-1 was absent in enhancement facilities and freshwater catchments and predominately found in the marine environment. Detections of PRV-1 varied greatly between species, year and stock of origin, but cumulatively identified that life history and migratory behaviors likely influenced viral prevalence. Specifically, Chinook salmon, which demonstrate long residence time in the Strait of Georgia relative to other species, had the highest PRV-1 prevalence in this study (7.4%). However, varying stock composition and regional detection between year classes within the Strait of Georgia indicated that main sources of infection were likely highly variable between years. These findings enhance our understanding for PRV-1 transmission in the region and more generally between/within salmon species.