Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Carl P. J. Mitchell; Brian A. Branfireun; Randall K. Kolka
    Date: 2009
    Source: Water Resources Research. 45(2):W02406.
    Publication Series: Scientific Journal (JRNL)
    Station: Northern Research Station
    PDF: View PDF  (1.26 MB)

    Description

    Peatlands are important environments for the transformation of atmospherically deposited inorganic mercury into the bioaccumulative form, methylmercury (MeHg), which may accumulate in downstream aquatic biota, particularly in fish. In recent research, it was suggested that MeHg production and/or accumulation ‘‘hot spots’’ at the upland-peatland interface were the result of upland fluxes of sulfate and labile dissolved organic carbon (DOC) into the peatland margin. Along the upland-peatland interface, spatial heterogeneity of "hot spots" was thought to be a result of variations in upland hydrologic interaction with the peatland margin. This hypothesis was tested in this study. Pore water MeHg, sulfate, and dissolved organic carbon (DOC) concentrations were compared in peatland plots at the base of both topographically concave and linear upland subcatcments in Minnesota. Subcatchment contributing areas were 3-8 times larger in the peatland plots adjacent to areas of concave upland topography. Peat pore water MeHg concentrations were significantly higher in these plots. Fluxes of water, sulfate, and dissolved organic carbon (DOC) from the upland hillslope into the peatland margin were also generally much larger than those from below areas of concave upland topography. Taken together, these results suggest that watershed geomorphology plays an important role in controlling chemical fluxes into peatland margins and consequently MeHg production and accumulation. It may thus be possible to delineate areas of high MeHg production and/or accumulation in certain watersheds by using high-resolution topographic data. The resulting MeHg "hot spots" may be important for locally foraging biota and for downstream loading, especially in the spring and fall.

    Publication Notes

    • Check the Northern Research Station web site to request a printed copy of this publication.
    • Our on-line publications are scanned and captured using Adobe Acrobat.
    • During the capture process some typographical errors may occur.
    • Please contact Sharon Hobrla, shobrla@fs.fed.us if you notice any errors which make this publication unusable.
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Mitchell, Carl P. J.; Branfireun, Brian A.; Kolka, Randall K. 2009. Methylmercury dynamics at the upland-peatland interface: Topographic and hydrogeochemical controls. Water Resources Research. 45(2):W02406.

    Cited

    Google Scholar

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page