HR: 0800h
AN: H41E-0336 INVITED     [Abstracts]
TI: Transport and transformation of mercury through soils from contrasting watersheds: Implications for resource management
AU: * Babiarz, C L
EM: babiarz@cae.wisc.edu
AF: University of Wisconsin-Madison, Environmental Chemistry and Technology Program 660 North Park Street, Madison, WI 53706 United States
AU: Hurley, J P
EM: Hurley@aqua.wisc.edu
AF: University of Wisconsin-Madison, Environmental Chemistry and Technology Program 660 North Park Street, Madison, WI 53706 United States
AU: Krabbenhoft, D P
EM: dpkrabbe@usgs.gov
AF: United States Geological Survey, Water Resources Division, Middleton, WI 53562 United States
AU: Stoor, R
EM: stoor@lbgmad.com
AF: University of Wisconsin-Madison, Environmental Chemistry and Technology Program 660 North Park Street, Madison, WI 53706 United States
AU: Manolopoulos, H
EM: manolopoulos@facstaff.wisc.edu
AF: University of Wisconsin-Madison, Environmental Chemistry and Technology Program 660 North Park Street, Madison, WI 53706 United States
AU: Meyer, M
EM: mhmeyer2@wisc.edu
AF: University of Wisconsin-Madison, Environmental Chemistry and Technology Program 660 North Park Street, Madison, WI 53706 United States
AU: Shafer, M
EM: mmshafer@facstaff.wisc.edu
AF: University of Wisconsin-Madison, Environmental Chemistry and Technology Program 660 North Park Street, Madison, WI 53706 United States
AB: Watersheds exert a strong influence on Hg cycling, and several studies have shown that characteristics such as soil type, glacial deposits, land use, and land cover control the fate and transport of Hg. Our ongoing research on several Northern Temperate rivers, suggest that more complex influences govern the formation, transport and partitioning of MeHg than previously understood. For instance, forested systems have been considered net sinks for MeHg, mainly delivered via direct atmospheric precipitation. However, forested systems can be a net source of MeHg if both subsurface deposits are highly conductive and proper redox conditions exist, or if discharge to a receiving stream passes through a microbially active hyporheic zone. Particle and colloidal partitioning of MeHg strongly influences bioavailability, and is dependent on surficial deposit types, dissolved organic carbon composition, and the susceptibility of the watershed to erosion. Similarly, inputs to watersheds are predicted to be highly dependent on atmospheric speciation and partitioning of Hg. In the Mercury Experiment To Assess Atmospheric Loading In Canada and the United States (METAALICUS), newly deposited Hg is differentiated from the standing pool using stable isotope amendments. The results will provide the first direct evidence of a watershed response to changing atmospheric inputs of mercury, and will inform pending controls on mercury emissions. Newly deposited mercury is initially retained on the watershed, and subsequent release is dependant on aging and complex soil-solute interactions. Mercury fate assessment models and management scenarios should incorporate these diverse watershed processes.
DE: 1806 Chemistry of fresh water
DE: 1832 Groundwater transport
DE: 1860 Runoff and streamflow
DE: 1890 Wetlands
DE: 1065 Trace elements (3670)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting