Total and methylmercury concentrations in ground and surface waters in natural and restored freshwater wetlands in northern New York
Autor: | Mario Montesdeoca, Kyotaek Hwang, Ting Wang, Charles T. Driscoll, David G. Chandler |
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Rok vydání: | 2020 |
Předmět: |
0106 biological sciences
Water flow Health Toxicology and Mutagenesis New York chemistry.chemical_element Fresh Water Wetland 010501 environmental sciences Management Monitoring Policy and Law Toxicology 01 natural sciences chemistry.chemical_compound Nitrate Dissolved organic carbon Ponds Groundwater Methylmercury Ecosystem 0105 earth and related environmental sciences geography geography.geographical_feature_category food and beverages General Medicine Methylmercury Compounds Mercury (element) 010602 entomology Deposition (aerosol physics) chemistry Wetlands Environmental chemistry Environmental science Water Pollutants Chemical Environmental Monitoring |
Zdroj: | Ecotoxicology. 29:1602-1613 |
ISSN: | 1573-3017 0963-9292 |
Popis: | Nearly half of freshwater wetlands have been lost due to human disturbance. In response, wetlands are being restored to retain their ecosystem services. A potentially adverse consequence of wetland function is the production of methylmercury (MeHg). We measured concentrations of mercury (Hg) species and ancillary parameters in groundwaters and surface waters from four natural and 16 restored wetlands in northern New York State, USA to investigate differences in concentrations of Hg species among wetlands. We found no obvious differences in concentrations of total mercury (THg) and methylmercury in pond waters between natural and restored wetlands. High values of %methylmercury were evident in both ground (38.8 ± 27.6%) and surface waters (43.4 ± 25.6%) suggesting these wetland complexes are highly efficient in converting ionic Hg to methylmercury, regardless if restored or natural. High methylation efficiency may be due to observed drying and rewetting cycles. Hg in pond waters is likely derived from direct atmospheric deposition or by mobilization from near-wetland shallow sediments, in addition to groundwater inflows. Water flow of groundwaters from the associated watershed into pond waters resulted in increases in concentrations of THg and methylmercury. Dissolved organic matter likely plays an important role in the supply of Hg to pond waters. Relationships between methylmercury and %methylmercury with sulfate and nitrate in groundwaters may suggest some chemical limitation on Hg methylation at higher concentrations of these anions. Because of the similarity in Hg dynamics for natural and restored wetlands, the most effective strategy to mitigate methylmercury production would be to decrease atmospheric Hg deposition. |
Databáze: | OpenAIRE |
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