May 14, 2010
Canadian fish farms and activists work against sea lice problem
Joint effort by Canadian firms aims at reducing sea lice problem afflicting salmon.
Salmon farms in Broughton Archipelago are right in the middle of wild-fish migration routes. Aquaculture companies and environmental groups are tentatively working together for the first time here.
Marine Harvest Canada and the Coastal Alliance for Aquaculture Reform initiated an uneasy truce last year, and now fish-farm companies Grieg Seafood and Mainstream Canada have joined an effort to reduce sea lice on farm fish and fallow some farms during out-migration of pink salmon through the archipelago.
The Broughton Archipelago Management Plan shows more can be achieved with a ceasefire than war, said Crawford Revie, Canadian research chairman at the University of Prince Edward Island and a delegate at the international sea lice conference in Victoria.
Pink salmon, which go to sea when they are tiny and lack protective scales, are particularly susceptible to sea lice. After a 97% crash of stocks in 2002, scientist Marty Krkosek of the University of Washington warned some stocks were likely to become extinct unless action was taken.
Last year, Marine Harvest treated Broughton farms with the pesticide Slice before the out-migration of pinks, and farms on one migration corridor were fallowed. This year, another migration corridor is being left fallow.
It is not yet known what the effect will be on pink returns, but levels of lice have dropped, said Craig Orr, executive director of the Watershed Watch Salmon Society and a member of the Coastal Alliance for Aquaculture Reform. "There are indications that the management actions creating a corridor are reducing infection pressures," he said.
Krkosek is monitoring wild fish and Revie is monitoring farm fish. However, Orr warned that Slice treatments and fallowing are temporary solutions and moving farms to closed containment is the permanent solution. "We have to get farms out of the water and get them on land. We must put a wall between the farm fish and the environment," Orr said.
Marine Harvest is working on a closed-containment pilot project, but land-based salmon farms are not yet operating on a commercial scale. Revie warned closed containment presents its own problems. The carbon footprint is larger and closed containment could consign fish to a quality of life similar to that of battery chickens, he said.
Meanwhile, conservation biologist Michael Price, who works with Raincoast Conservation Society and presented a research paper at the conference, wants to see similar migration corridors cleared for sockeye salmon (red salmon) in the Discovery Islands, where the majority of the troubled Fraser stocks out-migrate.
There is little research on the effect of lice on sockeye, which do not go to sea until they are larger, and thus are less susceptible to lice. "But when a small fish is just starting its migration, lice are unlikely to be beneficial and we are talking about an endangered species," he said.
