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Factors controlling mercury transport in an upland forested catchment

Water, Air, and Soil Pollution

By:
, , and
DOI: 10.1023/A:1005053509133

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Abstract

Total mercury (Hg) deposition and input/output relationships were investigated in an 11-ha deciduous forested catchment in northern Vermont as part of ongoing evaluations of rig cycling and transport in the Lake Champlain basin. Atmospheric Hg deposition (precipitation + modeled vapor phase downward flux) was 425 mg ha-1 during the one-year period March 1994 through February 1995 and 463 mg ha-1 from March 1995 through February 1996. In the same periods, stream export of total Hg was 32 mg ha-1 and 22 mg ha-1, respectively. Thus, there was a net retention of Hg by the catchment of 92% the first year and 95% the second year. In the first year, 16.9 mg ha-1 or about half of the annual stream export, occurred on the single day of peak spring snowmelt in April. In contrast, the maximum daily export in the second year, when peak stream flow was somewhat lower, was 3.5 mg ha-1 during a January thaw. The fate of file Hg retained by this forested catchment is not known. Dissolved (< 0.22 ??m) Hg concentrations in stream water ranged from 0.5-2.6 ng L-1, even when total (unfiltered) concentrations were greater than 10 ng L-1 during high flow events. Total Hg concentrations in stream water were correlated with the total organic fraction of suspended sediment, suggesting the importance of organic material in Hg transport within the catchment. High flow events and transport with organic material may be especially important mechanisms for the movement of Hg through forested ecosystems.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Factors controlling mercury transport in an upland forested catchment
Series title:
Water, Air, and Soil Pollution
DOI:
10.1023/A:1005053509133
Volume
105
Issue:
1-2
Year Published:
1998
Language:
English
Publisher:
Kluwer Academic Publishers
Publisher location:
Dordrecht, Netherlands
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Water, Air, and Soil Pollution
First page:
427
Last page:
438
Number of Pages:
12