Gilmour, C. C., Smithsonian Environmental Rese, Edgewater, MD, USA, gilmourc@si.edu
Heyes, A. ., U. Maryland, Chesapeake Biological Lab., Solomons, MD, USA, heyes@cbl.umces.ued
Mitchell, C. P., Smithsonian Environmental Research Ctr, Edgewater, MD, USA, mitchellc@si.edu
Krabbenhoft, D. P., USGS, Middleton, WI, USA, dpkrabbe@usgs.gov
Orem, W. ., USGS, Reston, VA, USA, borem@usgs.gov
Aiken, G. ., USGS, Boulder,CO, USA, graiken@usgs.gov
Mason, R. P., U.Connecticut, Avery Point, CT, USA, robert.mason@uconn.edu

A CROSS-ECOSYSTEM SYNTHESIS OF THE BIOGEOCHEMICAL CONTROLS ON MERCURY METHYLATION

Over the past decade, we have examined the biogeochemical controls on net methylmercury production across a number of ecosystems, including coastal zones, estuaries, salt and freshwater marshes, and lacustrine systems. We will present a cross-system compilation of the main drivers of net mercury methylation – mercury concentration, sulfate, sulfide, general microbial activity and organic matter - on the MeHg content of sediments and wetland soils. A general model for the control of net Hg methylation in surfaces sediments and wetland soils will be presented that includes microbial activity and sediment geochemistry. Data to be presented will include new information from high sulfate and sulfide coastal sediments and soils in Chesapeake Bay and the mid-Atlantic continental shelf and slope. By compiling these data, we can begin to predict the magnitude of net MeHg production across different aquatic ecosystems, and the sensitivity of different types of ecosystems to changing mercury inputs.

Oral presentation

Presentation is given by student: No
Session #:187
Date: 03-07-2008
Time: 08:15