Aquatic Sciences Meeting, Albuquerque 2001

CS07 Biogeochemical Cycles

Date: Thursday, February 15, 2001, Time: 11:30:00 AM

Location: Cochiti/Taos

Heyes, A, , University of Maryland, Chesapeake Biological Laboratory, Solomons, USA, heyes@cbl.umces.edu

Gilmour, C, C, Academy of Natural Sciences, Estuarine Research Center, St. Leonard, USA, gilmour@acnatsci.org

Mason, R, P, University of Maryland, Chesapeake Biological Laboratory, Solomons, USA, mason@cbl.umces.edu

Connell, D, B, University of Maryland, Chesapeake Biological Laboratory, Solomons, USA, connell@cbl.umces.edu

Rudd, J, W, Freshwater Institute, Winnipeg, Canada, Ruddj@dfo-mpo.gc.ca

METHYLMERCURY PRODUCTION IN BOREAL WETLANDS: USING STABLE ISOTOPES

Wetlands contain large pools of methylmercury (MeHg) and are significant sources to lakes, but little is known about MeHg production within wetlands. METALLICUS is a whole ecosystem study with the aim of separating the contributions of newly deposited Hg from older catchment Hg to MeHg concentrations in fish, and the relative importance of uplands, wetlands and lakes. In the long term, this will be done by applying different Hg isotopes to the three catchment components and tracking their movement. In the short term, we hypothesize that Hg methylation rates in wetland will be dynamic, thus understanding short term rates and controls on Hg methylation is essential for data extrapolation. To assess instantaneous rates, peat collected monthly over the summer was dosed with a Hg isotope and incubated for 4 hr periods. To assess intermediate term methylation rates, litter bags containing peat dosed with Hg isotope were placed in the wetland and retrieved at regular intervals. In this paper we will present the first look at intermediate and long term Hg methylation rates in boreal wetlands using stable isotopes.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks