Higher levels of mercury in North American fish – Queen’s study

Tuesday August 08, 2006, According to a recent Queen’s University study, mercury levels in fish are higher in North American lakes than in African lakes despite similar natural factors that contribute to mercury contamination on both continents.


Industrial processes introduce mercury as a contaminant to aquatic ecosystems in addition to the mercury that occurs naturally in the environment.

The study results, presented this week at the international Mercury 2006 conference at the Sea Grant Institute at the University of Wisconsin-Madison, suggest that although factors affecting the rate at which mercury concentration increases as it moves up the food chain are relatively consistent in the lakes studied, the mercury concentrations in fish are different in temperate than in tropical lakes.

“In times of increasing human population density and intensifying demands on our natural resources, aquatic ecosystems remain among our most precious global assets,” says lead researcher Linda Campbell, Canada Research Chair in Aquatic Ecosystem Health, and an assistant professor in both the Department of Biology and School of Environmental Studies at Queen’s.

“Human impact on the environmental and how we sustain the environment as a result will become increasingly important socially, economically and politically for the future. In order to effectively protect our aquatic ecosystems, we must first understand both the degree of contamination and where it comes from,” she adds.

Dr. Campbell has compared mercury contamination and food chain interactions across latitudes, lake sizes and climates, using databases for different sized lakes that support different food chains in tropical, temperate and arctic areas assembled over the last 10 years, and a review of other biological factors that cause mercury levels to increase

Higher ratios of methylmercury in fish tissue have led to consumption advisories world-wide in recent years. Studies have shown food chain length in lakes to be a good indicator of mercury concentrations, with the highest concentration appearing in top predators, which are usually food fish.

Dr. Campbell supervises a lab with 17 student researchers active in various aspects of aquatic ecosystem research in Canada and across the globe.

Aquatic Ecosystem Health Laboratory

For more information or to arrange a telephone interview, please contact Sarah Withrow, 613 533-3280, withrows@post.queensu.ca or Molly Kehoe, 613 533-2877, kehoem@post.queensu.ca, News and Media Services


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Sarah Withrow

News and Media Services

Queen’s University

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