Some Ecological Concerns for Net-Pen Culture of Salmon on the Coasts of the Northeast Pacific and Atlantic Oceans, with Special Reference to British Columbia

Abstract

Research data to predict the ecological implications of using fjords in waters on British Columbia for intensive salmon farming are sparse compared to those for similar habitats in Washington, U.S.A.; Scotland; and Norway. Water quality probelms due to changes in dissolved oxygen and nutrients can be overcome if siting criteria supported by good data can be developed. A coastal habitat classification system could help put the siting of fish farms on an ecological basis. The risk of sitting farms in areas where hypernutrification could be a problem may be low relative to other fjord areas, since the British Columbia coast has considerably stronger tidal currents and fewer poorly-flushed basins than Norway and Scotland. The genetic implications of farmed fish interbreeding with wild stocks are difficult to investigate without a parallel study on hatchery-raised salmonids, since the latter currently are more abundant than fish raised on farms. Contaminants from antibiotic residues in sediments and from disea...