Yet another sea lice study out in B.C.
The current issue of the North American Journal of Fisheries Management contains the latest in a series of publications authored by long-standing industry critics Alexandra Morton, Rick Routledge and Martin Krkosek. Titled "Sea Louse Infestation in Wild Juvenile Salmon and Pacific Herring Associated with Fish Farms off the East-Central Coast of Vancouver Island, British Columbia", the study, carried out in 2005 and 2006 in an area just north of Campbell River, claims that wild salmon and herring "exposed to salmon farms" were infected with more sea lice than those in the peripheral category.
Although the study states that "Sea louse abundance on Sockeye salmon and Pacific herring followed the same trends, but sample sizes were too low to support formal statistical analysis", the authors still conclude that "These results suggest that the association of salmon farms with sea lice infestations in wild juvenile fish in Pacific Canada now extends beyond juvenile Pink and Chum salmon in the Broughton Archipelago. Canada's most abundant and economically valuable salmon populations (Fraser River Sockeye salmon- author's note), as well as British Columbia's most valuable Pacific herring stock, migrate through the Discovery Islands, hence, parasite transmission from farm to wild fish in this region may have important economic and ecological implications".
No monitoring data from government researchers are available from this geographical area. Salmon farms located within the study area kept the sea lice numbers below government established maximum levels through the study period. The area is also known for its strong currents, and it is estimated that sea lice eggs shed from farmed salmon will drift significant distances before developing to the copepodid stage when juvenile sea lice can attach themselves to fish. Particle tracking research in the Broughton Archipelago predicted that sea lice released in the vicinity of two farms located deep in the archipelago are carried 10 km to 40 km from the farms before they become infective.
