Rada, R. G., Wiener, J. G., Winfrey, M. R., and Powell, D. E., 1989, Recent
increases in atmospheric deposition of mercury to North-Central Wisconsin lakes
inferred from sediment analyses: Archives of Environmental Contamination and
Toxicology, v. 18, no. 1-2, p. 175-181.

Abstract: 

Profiles of total mercury (Hg) concentrations in sediments were examined in 11
lakes in north-central Wisconsin having a broad range of pH (5.1 to 7.8) and
alkalinity (-12 to 768 mu eq/L). Mercury concentrations were greatest in the top 15
cm of the cores and were much lower in the deeper strata. The Hg content in the
most enriched stratum of individual cores ranged from 0.09 to 0.24 mu g/g dry
weight, whereas concentrations in deep, precolonial strata ranged from 0.04 to 0.07
mu g/g. Sediment enrichment factors varied from 0.8 to 2.8 and were not correlated
with lake pH. The data imply that a potentially significant fraction of the high Hg
burdens measured in game fish in certain lakes in north-central Wisconsin
originated from atmospheric sources.

Keywords: 

mercury, lakes, heavy-metals, sedimentation, sediment-analysis, bioaccumulation,
Pisces, USA, Wisconsin, deposition