Project Summary:

The objective of this project is to establish the role of land use and high-flow events in the mobility of mercury (Hg) and methyl-mercury (MeHg) in the Lake Champlain Basin. This research will lead to a scientific journal article of both regional and international interest. Topics include: (1) A Hg and MeHg mass balance for the Lake Champlain basin; (2) Hg methylation potential as a function of upstream land use and hydrologic landscape position; (3) Hg and MeHg dynamics during high-flow events; and (4) Controls on Hg and MeHg transfers from the drainage basin to the Lake. This study combines a synoptic-survey mass-balance approach with targeted intensive watershed investigations of Hg and Me-Hg cycling.

This investigation has encompassed 5 years and will include 5 activities: (1) synoptic sampling of tributary stream sediments; (2) synoptic snowmelt surveys of tributary stream waters; (3) a three-year fixed-site monitoring program for major tributary stream waters; (4) intensive watershed investigations for targeted land uses/land covers; and (5) limited in-lake sampling of littoral waters and sediments. In year 1 (2001), we conducted a one-time sediment survey and a one-time spring snowmelt high-flow stream survey, and selected long-term stream monitoring sites. In year 2, we implemented the fixed-site monitoring program for major inflow tributaries and the outflow from the Lake. In year 3, additional major inflow tributaries were sampled as well as locations within the lake. In 2004, data began to be analyzed. In 2005, data analysis was completed and a draft journal paper prepared. This paper is currently in review and will be submitted to a journal in early 2006. A Lake Champlain Basin Program fact sheet that contains a summary of this study is also planned to be completed.