Microbial constraints on MeHg production and accumulation in aquatic ecosystems
Methylmercury (MeHg), the toxic bioaccumulative form of mercury, is produced by microorganisms living in anoxic environments. Identifying the processes that lead to MeHg accumulation in freshwater ecosystems is a key step in understanding MeHg accumulation in aquatic food webs. MeHg production is limited by bioavailability constraints on inorganic Hg and the Hg methylation capacity of the microbial community. My focus is primarily on understanding the in situ microbial communities that directly and indirectly mediate the production of MeHg and how their capacity for Hg methylation interacts with factors controlling bioavailability. While I specialize in using meta-omics data, I use a multi-disciplinary approach that also includes biogeochemical field measurements, microbial activity assays, and stable isotope incubations. Below are some of the studies I have published as part of my Ph.D. thesis.