The federal department Fisheries and Oceans Canada (DFO) describes sea lice as a naturally occurring parasite commonly affecting several species of fish in oceans all over the world.

The DFO cites a stack of scientific reports supporting its conclusion that “they graze on the mucous and skin of fish, and usually have little impact on their health and survival” (dfo-mpo.gc.ca; select “Aquaculture” under “Subjects,” then “Sea Lice” under “More Info On”; for supporting reference sources, Google “dfo publications” and “salmon aquaculture”).

Environmentalists, however, disagree with this benign definition. In September 2007, 18 scientists supporting an opposing view signed an open letter to Prime Minister Stephen Harper and Premier Gordon Campbell. “We are convinced by the published scientific evidence that the debate is over; sea lice breeding on farmed salmon are threatening B.C.’s wild Pacific salmon,” the letter states. “There is now extensive peer-reviewed science that sea lice spread from farm to wild salmon and kill juvenile wild salmon.”

The Broughton Archipelago, near Telegraph Cove on Vancouver Island, is ground zero in the controversy. There are numerous salmon farms in the area, and sea lice have been identified on farmed and wild salmon species. Environmentalists believe sea lice from farmed fish are responsible for high mortality levels over the years of pink salmon in this area and that the wild fish are subject to lice infestations as they swim by the farms.

In December 2007, a study led by Martin Krkosek of the University of Alberta was published in Science magazine, citing evidence that sea-lice infestations spreading from farmed salmon in the area threaten the extinction of wild stocks of nearby pink salmon.

DFO research to date contradicts that conclusion, claiming that since 1987, when fish farms were introduced, pink salmon runs in the Broughton have in fact been higher than the 50-year average.

The DFO claims on its website that “research during the past three years does not support the notion that juvenile salmon travel through specific ‘migration corridors’ in the Broughton Archipelago on their way out to the ocean. DFO research shows evidence that sea lice levels are not affecting pink and chum salmon stocks in the Broughton Archipelago.”

Scientific research is ongoing, with a number of projects moving forward under the auspices of the B.C. Pacific Salmon Forum, a provincial government initiative established in 2004. A $3-million, two-year program funded by government and private-sector stakeholders will run through 2008. The status of the forum’s research, complete with the latest reports and updates, can be found at pacificsalmonforum.ca.

Back to Hook, line and sinker by Don Whiteley