Mercury trends and cycling in northern Wisconsin related to atmospheric and hydrologic processes
| Autor: | Carl J. Watras, Lori S. Tate, Alexander W. Latzka, David Grande |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
chemistry.chemical_element 010501 environmental sciences Aquatic Science Atmospheric sciences 01 natural sciences Mercury (element) Multiple factors chemistry Environmental science Cycling Surface water Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 76:831-846 |
| ISSN: | 1205-7533 0706-652X |
| DOI: | 10.1139/cjfas-2018-0157 |
| Popis: | Atmospheric deposition is the principal source of mercury (Hg) to remote northern landscapes, but its fate depends on multiple factors and internal feedbacks. Here we document long-term trends and cycles of Hg in the air, precipitation, surface water, and fish of northern Wisconsin that span the past three decades, and we investigate relationships to atmospheric processes and other variables, especially the regional water cycle. Consistent with declining emission inventories, there was evidence of declining trends in these time series, but the time series for Hg in some lakes and most fish were dominated by a near-decadal oscillation that tracked the regional oscillation of water levels. Concentrations of important solutes (SO4, dissolved organic carbon) and the acid–base status of lake water also tracked water levels in ways that cannot be attributed to simple dilution or concentration. The explanatory mechanism is analogous to the “reservoir effect” wherein littoral sediments are periodically exposed and reflooded, altering the internal cycles of sulfur, carbon, and mercury. These climatically driven, near-decadal oscillations confound short or sparse time series and complicate relationships among Hg emissions, deposition, and bioaccumulation. |
| Databáze: | OpenAIRE |
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