Fish-farming Tilapia in B.C.

Christopher Pollon
April 2, 2010
BC Business

Critics liken many B.C. marine salmon farms to modern factory farms and feedlots on land: maximizing the number of animals in a pen enhances profitability but also creates unnatural conditions where disease and parasites can thrive.

By far the biggest problem associated with B.C. salmon farms has been sea lice, which are small, naturally occurring ocean parasites that latch on to the skin of fish and feed on their fluids. While they do not usually harm adult salmon, the number of sea lice can be magnified by the density of the farmed fish, and such concentrations have been implicated in the demise of wild juvenile salmon migrating in proximity to fish farms.

Open-net cages have been blamed for the escape of at least 1.5 million farmed Atlantic salmon into the wild since B.C. salmon farming began in the 1980s. University of Victoria ecologist John Volpe has documented the presence of Atlantic salmon in at least 80 B.C. rivers to date and has confirmed that they have successfully reproduced in three rivers on the northeast coast of Vancouver Island.

“We’re now putting millions of non-native Atlantic salmon, year-round, in near-shore marine waters, and there is just no way to avoid interactions with wild fish,” says Craig Orr, an ecologist and executive director of Coquitlam-based environmental group Watershed Watch Salmon Society. “We do not believe that a system that allows the passage of parasites, disease, feces and uneaten food, back and forth into the marine environment from the salmon farms, is a sustainable way to farm.”

Orr says B.C. salmon farms must make a transition to “closed containment,” which entails separating the fish from the marine environment, whether in ocean tanks or taking them out of the water altogether, as in the case of tilapia farming.

Marine Harvest Canada, a division of the Norway-based Marine Harvest ASA, the world’s largest salmon aquaculture company and B.C.’s biggest, is appealing to the federal and provincial governments for money to do just that. In co-operation with a coalition of environmental groups known as the Coastal Alliance for Aquaculture Reform – including Orr’s Watershed Watch and the David Suzuki Foundation – Marine Harvest is working on designing and securing funding for a closed-containment pilot project this year.

Read the full story in BC Business