Methylmercury production in two urban artificial wetlands

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Kristina Morales (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Malcolm Schug

Abstract: Artificial wetlands created in urban areas are ecosystems that provide important services for the management of stormwater, pollutants, and erosion as well as have the potential to support rich biodiversity, unfortunately, they can produce a potent bioaccumulative neurotoxin, methylmercury (MeHg). There exists a need to further elucidate the spatial extent, temporal variation, and biotic export of MeHg from artificial wetlands. In North Carolina, specifically, MeHg concentrations for these systems have yet to be investigated. To address this knowledge gap we compared two artificial wetlands constructed the same year on the campus of the University of North Carolina at Greensboro and conducted a 3-year study measuring MeHg in the surface waters, sediments, and key export organisms for these wetlands. We found that following the installation of the two wetlands MeHg concentrations at these two sites have increased (using campus streams to infer baseline conditions). Mean subsurface sediment samples taken at the wooded wetland site (WS) compared to the open site wetland (OS) were higher in respect to THg concentration and MeHg concentrations, indicating the importance of landscape features in the production and accumulation of MeHg. Mean methylmercury concentrations in pooled Neurocordulia larva samples were observed to be significantly higher at the OS wetland compared to WS . This could be attributed to the presence of organic matter and differences in food chain length that occur between the sites. This information regarding mercury cycling in North Carolina urban areas that can advise future management and construction practices and provide a robust preliminary understanding of how continuing to construct artificial wetlands may enhance MeHg concentrations in urban watersheds.

Additional Information

Publication
Dissertation
Language: English
Date: 2022
Keywords
Artificial wetlands, Constructed wetlands, Mercury, Methylmercury, Urban, Wetlands
Subjects
Constructed wetlands $z North Carolina $z Greensboro
Urban ecology (Biology) $z North Carolina $z Greensboro
Wetland ecology $z North Carolina $z Greensboro
Methylmercury

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