Mercury and Fish

November 6, 2006

WHOI scientists and colleagues at the University of Connecticut have
found the first connection between mercury levels in freshwater fish and
atmospheric mercury pollution, most of which is derived from fossil fuel
combustion.  By comparing results from large databases for both mercury
concentrations in largemouth bass, a widely distributed freshwater fish
species, and atmospheric mercury deposition from monitoring efforts
across the contiguous U.S., the researchers found that mercury levels
are directly related to the flux of mercury from the atmosphere, which
varies five-fold among the states in the analysis. Anthropogenic mercury
emissions, mostly from the combustion of fossil fuels, have been
estimated to have increased atmospheric mercury levels and deposition
about three-fold globally since the Industrial Revolution, suggesting
that concentrations of methylmercury in aquatic systems worldwide may
have been lower in the pre-industrial past.  Future reductions in
anthropogenic mercury emissions to the atmosphere could result in
proportionally lower levels of methylmercury in aquatic organisms like
fish.  Results will be published in the November 15 print issue of the
journal Environmental Science & Technology and are available now in the
online version on the journal.