Environmental Science

Mecury Biomagnification

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Science  15 Nov 2013:
Vol. 342, Issue 6160, pp. 779
DOI: 10.1126/science.342.6160.779-a

In aquatic ecosystems, mercury is converted to methylmercury, which can be accumulated in top predators at levels millions of times higher than in surface waters. This biomagnification can result in toxic concentrations in fish and fish-eating species. However, mercury concentrations in fish and invertebrates differ widely between ecosystems, and it remains unclear whether biomagnification is only affected by food web processes such as growth rate and species diversity or also by physicochemical variables such as water pH, temperature, and nutrient concentrations. Lavoie et al. have compiled data from 69 studies of marine and freshwater ecosystems around the globe to determine the total mercury and methylmercury tropic magnification slopes, which are key indicators of the biomagnifying potential in food webs. The results show biomagnification to be highly variable among the reviewed sites. It is positively related to latitude and highest in cold, low-productivity ecosystems. A combination of variables related to temperature is likely to be responsible for the latitude effect, but the mechanism remains unclear.

Environ. Sci. Technol. 10.1021/es403103t (2013).

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