Rada, R. G., Powell, D. E., and Wiener, J. G., 1993, Whole-lake burdens and spatial
distribution of mercury in surficial sediments in Wisconsin seepage lakes: Canadian
Journal of Fisheries and Aquatic Sciences, v. 50, no. 4, p. 865-873.

Abstract

We quantified total mercury in surficial sediments (uppermost 5 cm) of six small
seepage lakes. Fifty cores were taken from each lake, based on a random sampling
design stratified by water depth. Volumetric concentrations (mass per volume of wet
sediment) more accurately portrayed the depth distribution of mercury in the lakes than
did dry-weight concentrations, which underrepresented the significance of the
shallow-water sediments as a reservoir of potentially available mercury. Estimates of
whole-lake burdens (masses) of mercury in the surficial sediment, which represents the
maximum amount of sedimentary mercury available for methylation, ranged from 45
to 149 g. We hypothesize that the observed variation in areal burdens of mercury was
partly due to variation among lakes in the pH-related efflux of gaseous mercury (Hg
super(0)) from the lakes to the atmosphere.

Keywords

mercury, sediment-pollution, near-surface-layer, distribution, sediment-chemistry,
freshwater-lakes, USA, Wisconsin