The Costs of Eutrophication from Salmon Farming: Implications for Policy

We examine the ecological and economic costs of environmental impacts caused by coastal cage farming of salmonids, in particular those associated with nutrient releases and their relation to eutrophication and toxic algal blooms. We find that the nutrient releases from a fish farm producing 100 tons of salmon correspond to those of a human settlement of 850-3200 persons. Extrapolating the results to the 200 000 tons of salmonid production by Nordic countries, the release exceeds those of the population of Stockholm, the largest city in Sweden, and even whole states, such as Lithuania. Internalizing the environmental cost of the nutrient release from salmon farms at the level of the firm reveals that the total cost of salmon production exceeds the highest price paid for salmon in the 1980s, the decade when the industry boomed. In addition, there are several other environmental impacts not internalized. It is concluded that, from the viewpoint of Swedish society, salmonid farming, as performed today in coastal waters, is not only ecologically but also economically unsustainable.