Physical controls on total and methylmercury concentrations in streams and lakes of the northeastern USA
Ecotoxicology
By: J. B. Shanley, N.C. Kamman, T.A. Clair, and A. Chalmers
Links
- More information: Publisher Index Page (via DOI)
- Download citation as: RIS | Dublin Core
Abstract
The physical factors controlling total mercury (HgT) and methylmercury (MeHg) concentrations in lakes and streams of northeastern USA were assessed in a regional data set containing 693 HgT and 385 corresponding MeHg concentrations in surface waters. Multiple regression models using watershed characteristics and climatic variables explained 38% or less of the variance in HgT and MeHg. Land cover percentages and soil permeability generally provided modest predictive power. Percent wetlands alone explained 19% of the variance in MeHg in streams at low-flow, and it was the only significant (p < 0.02) predictor for MeHg in lakes, albeit explaining only 7% of the variance. When stream discharge was added as a variable it became the dominant predictor for HgT in streams, improving the model r 2 from 0.19 to 0.38. Stream discharge improved the MeHg model more modestly, from r 2 of 0.25 to 0.33. Methylation efficiency (MeHg/HgT) was modeled well (r 2 of 0.78) when a seasonal term was incorporated (sine wave with annual period). Physical models explained 18% of the variance in fish Hg concentrations in 134 lakes and 55% in 20 reservoirs. Our results highlight the important role of seasonality and short-term hydrologic changes to the delivery of Hg to water bodies. ?? 2005 Springer Science+Business Media, Inc.
Suggested Citation
Shanley, J.B., Kamman, N., Clair, T., Chalmers, A., 2005, Physical controls on total and methylmercury concentrations in streams and lakes of the northeastern USA: Ecotoxicology, v. 14, no. 1-2, p. 125-134, https://doi.org/10.1007/s10646-004-6264-z.
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Physical controls on total and methylmercury concentrations in streams and lakes of the northeastern USA |
| Series title | Ecotoxicology |
| DOI | 10.1007/s10646-004-6264-z |
| Volume | 14 |
| Issue | 1-2 |
| Year Published | 2005 |
| Language | English |
| Larger Work Type | Article |
| Larger Work Subtype | Journal Article |
| Larger Work Title | Ecotoxicology |
| First page | 125 |
| Last page | 134 |