Study Shows Sea Lice Affecting Sockeye and Herring


SeafoodSource staff

Published on
April 2, 2008

A new scientific study has determined that sea lice near salmon farms off the coast of British Columbia are affecting juvenile sockeye salmon and Pacific herring.

The study, published in the April issue of the North American Journal of Fisheries Management, suggests sea lice have "important economic and ecological implications" for more marine species than pink and chum salmon, as previously thought.

Study author Alexandra Morton, a researcher with the Raincoast Research Society in Simoom Sound, B.C., said the results were discovered during testing of 47,000 young wild salmon in 2005 and 2006 near the Discovery Islands. According to the study, which was co-authored by Martin Krkosek of the University of Alberta, older herring are prone to lice but this is the first documentation of lice on herring that have not yet formed scales; infestation leaves the juveniles highly vulnerable.

Sea lice studies have concentrated in recent years on Broughton Archipelago, a region in British Columbia heavily concentrated with salmon farms. Many of Canada's abundant and economically valuable wild salmon and Pacific herring stocks migrate through the area, which is the chief cause of concern.

Late last year, a group of scientists and researchers wrote an open letter to Canadian Prime Minister Stephen Campbell urging him to stop the threat that sea lice from fish farms pose to wild salmon.

The group, including environmental activist David Suzuki and National Geographic Society explorer-in-residence Wade Davis, contends that sea lice from fish farms kill juvenile wild salmon and threaten the future of the species. They add that because wild salmon moving through fish farm areas are more likely to contract fatal infections, barriers between wild and farmed salmon and containment of fish farms are the only safeguards.

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