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Landscape controls on total and methyl Hg in the Upper Hudson River basin, New York, USA

Journal of Geophysical Research

By:
, , , , and
DOI: 10.1029/2011JG001812

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Abstract

Approaches are needed to better predict spatial variation in riverine Hg concentrations across heterogeneous landscapes that include mountains, wetlands, and open waters. We applied multivariate linear regression to determine the landscape factors and chemical variables that best account for the spatial variation of total Hg (THg) and methyl Hg (MeHg) concentrations in 27 sub-basins across the 493 km2 upper Hudson River basin in the Adirondack Mountains of New York. THg concentrations varied by sixfold, and those of MeHg by 40-fold in synoptic samples collected at low-to-moderate flow, during spring and summer of 2006 and 2008. Bivariate linear regression relations of THg and MeHg concentrations with either percent wetland area or DOC concentrations were significant but could account for only about 1/3 of the variation in these Hg forms in summer. In contrast, multivariate linear regression relations that included metrics of (1) hydrogeomorphology, (2) riparian/wetland area, and (3) open water, explained about 66% to >90% of spatial variation in each Hg form in spring and summer samples. These metrics reflect the influence of basin morphometry and riparian soils on Hg source and transport, and the role of open water as a Hg sink. Multivariate models based solely on these landscape metrics generally accounted for as much or more of the variation in Hg concentrations than models based on chemical and physical metrics, and show great promise for identifying waters with expected high Hg concentrations in the Adirondack region and similar glaciated riverine ecosystems.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Landscape controls on total and methyl Hg in the Upper Hudson River basin, New York, USA
Series title:
Journal of Geophysical Research
DOI:
10.1029/2011JG001812
Volume
117
Year Published:
2012
Language:
English
Publisher:
American Geophysical Union
Publisher location:
Washington, D.C.
Contributing office(s):
Minnesota Water Science Center, New York Water Science Center, South Carolina Water Science Center
Description:
15 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Geophysical Research
First page:
G01034
Time Range Start:
2006-01-01
Time Range End:
2008-12-31
Country:
United States
State:
New York
Other Geospatial:
Adirondack Mountains