NEWS

Tuesday, October 03, 2006

Study: Fish Farms Kill Wild Salmon

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Community: Vancouver Island

Commercial fish farms must change the way they operate to ensure the survival of wild fish stocks, says an author of a study that found parasites from the farms kill as much as 95 per cent of wild young salmon that pass by them.

The study, published on Monday, Oct. 2 by Martin Krkosek, a PhD candidate at the University of Alberta Centre for Mathematical Biology, received wide attention and media coverage for its sensational finding. Entitled Epizootics of wild fish induced by fish farms (PDF, 1.4 MB), the study supports the major concerns that those fighting fish farms have raised over the past decade in coastal BC, and codemns fish farms and their lobbyists.

In the absence of the fish farms, the juvenile salmon would normally have between three and five months to grow before they would be exposed to sea lice, which are typically carried by adult salmon, Krkosek said. The juvenile salmon would enter the ocean without lice months before the adult salmon return.

But the farms artificially concentrate large numbers of sea lice near salmon migration paths, forcing the juvenile salmon to pass through clouds of the parasites, the study found.

The mortality rates rise from a low of nine percent early on in the spring season to the peak of 95 percent as more juvenile salmon have increasing exposure to rising numbers of sea lice, according the study.

© CBC 2006

Mr. Krkosek was interviewed last night on the CBC current affairs show As It Happens (listen to part 1, Real Player only, and jump forward to 16:25, scroll down to Salmon & Lice for description) to answer questions about the study. The host tried to get him to soften his position, asking whether it was possible that fish farms and wild salmon populations could co-exist. To this, Mr. Krkosek was unequivocal in saying that wherever fish farms had appeared there was a clear pattern, in Europe and on the Atlantic coast, where fish farms led directly to plummeting wild fish populations.