Response of mercury in an Adirondack (NY, USA) forest stream to watershed lime application

Environmental Science: Processes and Impacts
By: , and 

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Abstract

Surface waters in Europe and North America previously impacted by acid deposition are recovering in conjunction with declining precursor emissions since the 1980s. Lime has been applied to some impacted watersheds to accelerate recovery. The response to liming can be considered a proxy for future recovery from acid deposition. Increases in dissolved organic carbon concentrations have been observed in surface waters in response to increased pH associated with recovery from acid deposition. Although not previously described, recovery-related increases in dissolved organic carbon could drive increases in mercury concentrations and loads because of the affinity of mercury for dissolved organic matter. We used a before–after impact-response approach to describe the response of stream mercury cycling to the application of lime to the watershed of a small stream in the Adirondack Mountains of New York, USA. Dissolved organic carbon, total mercury and methylmercury concentrations increased significantly in streamwater within two weeks of treatment, to previously unobserved oncentrations. After six months, post-treatment before–after impact-control (BACI) tests indicate that mean dissolved organic carbon concentrations and total mercury to dissolved organic carbon ratios remained significantly higher and limed site fluxes of methylmercury were lower than those at the reference stream. This pattern suggests total mercury is leaching at elevated levels from the limed watershed, but limitations in production and transport to the stream channel likely resulted in increases in methylmercury concentration that were of limited duration.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Response of mercury in an Adirondack (NY, USA) forest stream to watershed lime application
Series title Environmental Science: Processes and Impacts
DOI 10.1039/c7em00520b
Volume 20
Issue 4
Year Published 2018
Language English
Publisher The Royal Society of Chemistry
Contributing office(s) New York Water Science Center
Description 14 p.
First page 607
Last page 620
Country United States
State New York
Other Geospatial Honnedaga Lake