University at Albany Institute
for Health and the Environment

Several small, peer-reviewed pilot studies on farmed salmon

The results from several small peer-reviewed studies of farmed salmon have been inconclusive because they examined just a handful of fish samples - no more than 14 - from just a few locations. Nevertheless, these studies pointed to potentially significant differences in health risk between farmed and wild salmon:

  1. A study by Easton et al. in Chemosphere examined four farmed and four wild salmon purchased in British Columbia. It reports higher levels of PCBs, some organochlorine pesticides, and PBDEs (flame retardants) in the farmed salmon. The study found that contaminant levels in farmed salmon could be as much as ten times those in wild salmon. The study also suggested that the commercial salmon feed consumed by the farmed fish was responsible for the elevated contaminant levels. Differences between farmed and wild salmon were not notably different for other contaminants such as toxaphene and methylmercury. (M. D. L. Easton, D. Luszniak and E. Von der Geest, Preliminary examination of contaminant loadings in farmed salmon, wild salmon and commercial salmon feed. Chemosphere 46, 1053-1074 (2002).)

  2. A study by Jacobs et al. in Environmental Science & Technology found relatively high concentrations of PCBs and moderate concentrations of organochlorine pesticides and PBDEs in 13 samples of farmed Scottish and European salmon. (M. Jacobs; A. Covaci, and P. Schepens, Investigation of selected persistent organic pollutants in farmed atlantic salmon (Salmo salar), salmon aquaculture feed, and fish oil components of the feed. Environmental Science and Technology 36, 2797-2805 (2002).)

  3. Another study by Jacobs et al. in the journal Chemosphere found relatively high concentrations of dioxins and PCBs in 10 samples of farmed and wild Scottish salmon. The study concluded that high levels of farmed salmon consumption could lead to intakes of contaminants above tolerable daily and weekly levels when combined with intakes from the typical UK diet. (M. Jacobs, J. Ferrario, and C. Byrne, Investigation of polychlorinated dibenzo-p-dioxins, dibenzo-p-furans (sic) and selected coplanar biphenyls in Scottish farmed Atlantic salmon (Salmo salar). Chemosphere 47, 183-191 (2002).)

Information from the study's authors