MS

thesisThe bioavailable form of mercury, methyl mercury (MHg), has been shown by previous studies to be relatively high in the main body of the Great Salt Lake (GSL). A consumption advisory for several species of waterfowl from the GSL and surrounding wetlands was recently released due to findings of toxic mercury levels in those species. The GSL is a system of vertically and spatially connected "compartments," including shallow and deep brine layers in the main bays, as well as bays on the eastern side where fresh water is delivered from corresponding rivers. It is presently unknown which compartments and locations are predominant in transforming mercury to methyl mercury. One method used to investigate Hg methylation in sediment and water is to spike the sample with inorganic mercury enriched in a minor isotope and observe the evolution of methyl mercury concentrations in response, which was implemented in this study. Sediment and water samples were collected from sites along two east-west trending transects at the north and south ends of Farmington Bay in summer and fall. Water temperature, pH, conductivity, dissolved oxygen, sulfide and sulfate concentrations, and ambient total Hg and MHg concentrations were measured at each site. Total solids content and organic matter were evaluated for the sediment. Subsamples of the sediment and water from each site were spiked with 204Hg2+ and were incubated for 12, 24, 48, and 72 hours