Water Resources Research Act Program

Details for Project ID 2011NY161B

NITROGEN (N) AVAILABILITY AS DRIVER OF METHYLMERCURY PRODUCTION IN FORESTED SOILS AND STREAM SEDIMENTS

Institute: New York
Year Established: 2011 Start Date: 2011-06-01 End Date: 2013-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $40,392

Principal Investigators: Philippe Vidon

Abstract: Atmospheric deposition of nitrogen (N), sulfur (S) and mercury (Hg) is ubiquitous in the Northeastern United States and has a major impact on forest lands and water quality of this region (Mitchell et al., 2009). Many years of research in the Adirondacks and other northeastern forests have shown that soil and lake acidification is directly related to N and S atmospheric deposition (Mitchell et al., 2009). Forest production is also often limited by N availability, and increases in N atmospheric deposition have been shown to have deleterious environmental impacts. Atmospheric deposition of mercury (Hg) has been linked to increased level of Hg in fish, and mercury contamination is the most common cause of fish consumption advisories and was responsible in part for 80% of all state advisories in 2006 (USEPA, 2007). There is also evidence in the literature that significant interactions exist between the N, S and Hg cycles in many environments (see related work section). However, it is not known whether N concentrations resulting from atmospheric deposition of N in the Northeast have a significant impact on Hg dynamics in forested ecosystems. It is critical to answer this question in order to understand how forested ecosystems of the Northeast will respond to changes in the rates of N, S and Hg atmospheric deposition in the coming years, along with changes in climate (precipitation regime, temperature, snow cover). Based on our current understanding of the relationships between N, S and Hg cycling (see related work section), we hypothesize that the addition of N via atmospheric deposition may limit S reduction and ultimately methylmercury (MeHg) production. Ultimately, we believe that increase in N level in forested ecosystems of the Northeast will impact Hg dynamics in watersheds, and ultimately MeHg availability and potential toxicity at the ecosystem level.