Juvenile Salmon Ecology Project
The depletion of marine fisheries has been an impetus to expand seafood production through aquaculture. In BC, salmon farming has grown considerably in response to a decline in salmon stocks and an increase in the global appetite for fish. Despite industry claims, salmon farming merely supplements, rather than substitutes for fishing. Because salmon are carnivores, farming them relies on the capture of finite supplies of wild fish for use in fish feeds.
To date, there are roughly 111 salmon farm tenures throughout BC’s coast, with the heaviest concentration on the south coast. Despite a current suspension on farm expansion on BC’s north coast, the industry is poised to expand further in the south (fish farm expansion map).
As aquaculture is not substituting for wild fisheries, heavy dependence on wild fish inputs is a concern. Documented impacts and current threats to local wild salmon include escapes of farmed Atlantic salmon, disease transfer from farm to wild fish, and sea lice infestations from farm to wild juvenile salmon. Population collapse of local salmon stocks due to farm-induced lice infestations have been recorded.
Host-parasite relationships and salmon farms
Pacific Salmon Forum research (central coast sea lice monitoring)
Field work and analysis conducted during 2007-2008 examined the intensity of sea lice infection on wild juvenile pink and chum salmon in the Bella Bella region of the BC central coast (an area without fish farms) for comparison with intensities of infection from areas that contain fish farms.
The project compared data with active salmon farming regions (Klemtu, Broughton Archipelago, and the northern Georgia Strait). Lice levels increased in concert with farm salmon production. Juveniles assessed at sites far from farms in Klemtu hosted similar lice levels to fish examined at Bella Bella, and hosted consistently elevated levels near farms. Lice levels were highest among the northern Georgia Strait (home to 32 salmon farms; see Final Report on central coast sea lice). This manuscript is in review.
Fraser sockeye early marine ecology project
This project investigates the marine ecology of Fraser River sockeye smolts. Fraser sockeye are Canada’s largest and most lucrative salmon runs. Our objective is to ascertain if, and if so what degree, salmon farms situated along the Georgia Srait migration route of juvenile sockeye might impair their health.
2009 was the lowest return of sockeye salmon ever recorded, despite favourable ocean conditions and an exceptionally large out-migration of fry during 2007. Our preliminary data from the 2007 outbound migration of the Fraser stocks is raising concern that salmon farms may be enhancing parasitic infections on sockeye smolts. In the Broughton, overwhelming evidence has indicated that such an association has contributed to the decline of pink and chum salmon. This research is advancing the field of aquatic ecology by examining a new host-parasite relationship in an understudied region. Moreover, this project builds on similar work Raincoast has conducted on pink and chum smolts in areas of differing salmon farm density.
Download: Salmon farms in BC
Download: Proposed salmon farm expansion
Download: Final Report to Pacific Salmon Forum on central coast sea lice monitoring