Trace Element Loadings to Sediments of Fourteen Ontario Lakes and Correlations with Concentrations in Fish

Abstract

Present, background, and anthropogenic loading rates of Cu, Ni, Zn, Pb, Cd, Cr, Hg, As, and Se to lake sediments were calculated from 210 Pb dated cores, and present loading rates were compared with concentrations in several fishes. Present loadings of Pb averaged 17 times background loadings and all lakes had statistically significant anthropogenic inputs. The majority of lakes had anthropogenic loadings of Zn, Cd, Hg, and As, which were presently 1.8–2.6 times background loadings. For Ni, Cu, Se, and Cr, only seven, five, two, and one lake(s), respectively, had significant anthropogenic inputs, and the means of present: background loadings for all lakes were not significantly different from 1.0. Enrichment by Zn, Cd, As, and especially Pb was greater closer to industrialized regions, while Hg enrichment was more widespread. Anthropogenic and precipitation loadings for Zn, Pb, Cd, and As were similar, suggesting that anthropogenic inputs are atmospheric and that current atmospheric loadings are mostly anthropogenic. [Hg] and [Cd] in fish were correlated with loadings to sediments, but [Cu] and [Zn] in fish were relatively constant within species, supporting the hypothesis that contaminants in fish would be correlated with inputs to sediments, while trace nutrients in ample supply would be unrelated to loading. [Cr] and [Se] in fish were intermediate in response to loading, but correlation between [Pb] in fish and loadings was not detected.