Date of Award
Doctor of Philosophy
Gary J. Atchison
Ronald G. Rada
I quantified cadmium in surficial sediments of six low-alkalinity seepage lakes in north-central Wisconsin. Dry-weight cadmium concentrations in the sediments (range 0.02-7.17 [mu]g · g[superscript]-1) were strongly correlated with water depth in all six study lakes. However, when cadmium concentrations were expressed on a volumetric basis (range 0.004-0.67 [mu]g · cm[superscript]-3) the positive correlation with water depth was significant for only one of the lakes. Whole-lake burdens of cadmium in sediments of the six lakes ranged from 625 to 5785 g and were strongly correlated with lake surface area, indicating that atmospheric deposition was the primary source of anthropogenic cadmium to the study lakes. Areal burdens of cadmium, which ranged from 62 to 92 g · ha[superscript]-1, were strongly correlated with dissolved organic carbon in the lakes, suggesting that the transport of cadmium to bottom sediments of the study lakes was related to organic material. Bioaccumulation of cadmium by yellow perch (Perca flavescens) was quantified in Little Rock Lake, the site of an experimental pH-manipulation project. To assess the influence of acidification on cadmium bioaccumulation by fish, yellow perch were annually netted from the treatment and reference basins of Little Rock Lake. Between-basin comparisons of cadmium in whole yellow perch indicated that lake pH significantly influenced cadmium bioaccumulation by fish. After 1 year of residence in the lake, mean whole-body concentrations and burdens of cadmium in age-1 yellow perch from the acidified treatment basin (pH 4.9) in April 1990 and 1991 were significantly less than whole-body concentrations and burdens of cadmium in fish from the non-acidified reference basin (pH 6.1). Moreover, mean whole-body concentrations and burdens of cadmium in age-2 and older fish sampled in 1989, after 2 years of acidification to pH 5.2, and in 1991, after 2 years of acidification to pH 4.9, were greater in the reference basin than the treatment basin. Bioaccumulation of cadmium by yellow perch paralleled rates of growth within the Little Rock Lake populations sampled in 1989 and 1991. Estimated cadmium inventories in the yellow perch populations of Little Rock Lake in 1989 were 24 mg in the reference basin and 19 mg in the treatment basin.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
David Emerson Powell
Powell, David Emerson, "Cadmium accumulation in the bottom sediments and fish of seepage lakes in north-central Wisconsin: relation to lake chemistry " (1993). Retrospective Theses and Dissertations. 10261.