Salmon sea-lice problem widespread: study

December 15, 2010

Document Tools

Print This Article

E-mail This Page

Font Size
S      M      L      XL

Related Links

SFU fish biologist John Reynolds has co-authored new research in the Canadian Journal of Fisheries and Aquatic Sciences (CJFAS) indicating B.C. salmon farms are transferring parasitic sea lice to wild salmon over a much greater area than previously thought.

The study finds that open-net-pen salmon farms are the primary source of parasitic sea lice on wild juvenile pink and chum salmon across wide swaths of coastal B.C., not just in the Broughton Archipelago.

Scientists have long connected salmon farms to sea lice on wild salmon in the Broughton Archipelago on the northeastern side of Queen Charlotte Strait, a key migratory route to the open ocean.

The new study reaffirms the connection but also establishes a link between fish farms and lice-infested wild salmon throughout Georgia Strait heading south and in Finlayson Arm on the Central Coast.

Several studies have shown that sea lice can be fatal to small juvenile salmon.

“Our research underscores the value of moving open-net-pen salmon farms out of migration routes of wild salmon, and ultimately into land-based closed containment systems,” notes Reynolds.

The study found that among wild juvenile salmon in most regions not exposed to fish farms, less than five per cent had sea lice. In contrast, 30 to 40 per cent of salmon near fish farms had the parasite.

Areas with the most fish farms, such as Georgia Strait, had the highest wild-fish lice-infection rates. Areas with no fish farms such as Bella Bella had the lowest rates.

Reynolds and his co-authors, biologists Michael Price and Alexandra Morton, note the highest sea-lice infestation of wild juveniles is in the Discovery Islands, a region with the highest farm-salmon production and through which Fraser River wild sockeye migrate.

To view the CJFAS article, “Evidence of farm-induced parasite infestations on wild juvenile salmon in multiple regions of coastal British Columbia, Canada”, visit:


Commenting is closed
Comment Guidelines
Search SFU News Online