Mercury export from the Yukon River Basin and potential response to a changing climate
We measured mercury (Hg) concentrations and calculated export and yield from the Yukon River Basin (YRB) to quantify Hg flux from a large, permafrost-dominated, high-latitude watershed. Exports of Hg averaged 4400 kg Hg yr-1. The average annual yield for the YRB during the study period was 5.17 μg m-2 yr-1, which is 3–32 times more than Hg yields reported for 8 other major northern hemisphere river basins. The vast majority (90%) of Hg export is associated with particulates. Half of the annual export of Hg occurred during the spring with about 80% of 34 samples exceeding the U.S. EPA Hg standard for adverse chronic effects to biota. Dissolved and particulate organic carbon exports explained 81% and 50%, respectively, of the variance in Hg exports, and both were significantly (p < 0.001) correlated with water discharge. Recent measurements indicate that permafrost contains a substantial reservoir of Hg. Consequently, climate warming will likely accelerate the mobilization of Hg from thawing permafrost increasing the export of organic carbon associated Hg and thus potentially exacerbating the production of bioavailable methylmercury from permafrost-dominated northern river basins.
Citation Information
Publication Year | 2011 |
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Title | Mercury export from the Yukon River Basin and potential response to a changing climate |
DOI | 10.1021/es202068b |
Authors | Paul F. Schuster, Robert G. Striegl, George R. Aiken, David P. Krabbenhoft, John F. DeWild, Kenna D. Butler, Ben Kamark, Mark Dornblaser |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Environmental Science & Technology |
Index ID | 70006305 |
Record Source | USGS Publications Warehouse |
USGS Organization | Branch of Regional Research-Central Region; Mercury Research Laboratory; Toxic Substances Hydrology Program |