Get access
Advertisement

Mercury and other trace elements in farmed and wild salmon from british Columbia, Canada

Authors

  • Barry C. Kelly,

    1. Fisheries and Oceans Canada, 9860 West Saanich Road, P.O. Box 6000, Institute of Ocean Sciences, Sidney, British Columbia V8L 4B2
    Search for more papers by this author
  • Michael G. Ikonomou,

    Corresponding author
    1. Fisheries and Oceans Canada, 9860 West Saanich Road, P.O. Box 6000, Institute of Ocean Sciences, Sidney, British Columbia V8L 4B2
    • Fisheries and Oceans Canada, 9860 West Saanich Road, P.O. Box 6000, Institute of Ocean Sciences, Sidney, British Columbia V8L 4B2
    Search for more papers by this author
  • David A. Higgs,

    1. Fisheries and Oceans Canada/University of British Columbia, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, British Columbia V7V 1N6
    Search for more papers by this author
  • Janice Oakes,

    1. Fisheries and Oceans Canada/University of British Columbia, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, British Columbia V7V 1N6
    Search for more papers by this author
  • Cory Dubetz

    1. Fisheries and Oceans Canada, 9860 West Saanich Road, P.O. Box 6000, Institute of Ocean Sciences, Sidney, British Columbia V8L 4B2
    Search for more papers by this author

  • Published on the Web 1/22/2008.

Abstract

The present study reports measured levels of Hg and other trace elements in commercial salmon feed; farmed Atlantic, coho, and chinook salmon (n = 110); and wild coho, chinook, chum, sockeye, and pink salmon (n = 91). Metal concentrations in farmed and wild salmon from British Columbia, Canada, were relatively low and below human health consumption guidelines. Methylmercury in all salmon samples (range, 0.03–0.1 μg/g wet wt) were below the 0.5 μg/g guideline set by Health Canada. Negligible differences in metal concentrations were observed between the various species of farmed and wild salmon. Metal concentrations generally were higher in commercial salmon feed compared to farmed salmon. Mercury showed slight bioaccumulation potential in farmed salmon, with biomagnification factors (BMFs) ranging between 0.8 and 1.9. Other metals, such as Cd, Pb, and Ni, exhibited biodilution, with BMFs of much less than one. The relatively low degree of biomagnification of metals observed in farmed salmon likely resulted from the combination of low gastrointestinal absorption efficiency, negligible transfer to muscle tissue relative to other compartments, and a high degree of growth dilution in these fish. Human dietary exposure calculations indicate intakes of Hg, Cd, Pb, Cu, As, and Ni via farmed and wild British Columbia salmon are a relatively small percentage of total intakes (0.05–32%) compared to other Canadian foodstuffs, such as fruits, vegetables, chicken, and beef (68–99%). Although total dietary exposure of Cd, Pb, and Cu approached provisional tolerable daily intake levels, the contribution from British Columbia salmon was less than 2%. Our findings indicate farmed and wild British Columbia salmon remain a safe source of omega-3 highly unsaturated fatty acid intake for cardioprotective and, possibly, other health benefits.

Get access to the full text of this article

Ancillary