|Abstract Title:||Assessing Methylmercury Concentrations in Invertebrates inhabiting Constructed Artificial Wetlands|
|Presenter Name:||Kristina Morales|
|Company/Institution:||University of North Carolina at Greensboro|
|Session:||Mercury in Freshwater Ecosystems|
Abstract Information :
As ubiquitous features of the urban landscape, wetlands have been recognized for their importance as habitats for many organisms and for a plethora of ecosystem services they can provide, making them popular ecosystems for construction and restoration projects. Yet, despite the growing abundance of constructed wetlands, there have not been many studies aimed at understanding and characterizing the biogeochemical cycling of Hg in these ecosystems. A consequence of insufficient monitoring is that little is known about the production, distribution, and transfer of toxic MeHg in these systems. Previous studies show increased MeHg concentrations in and around artificial wetlands, potentially contaminating aquatic systems and nearby riparian food webs. Our previous study investigated THg and MeHg concentrations (as well as presence of organic material) in water and sediment samples collected from 2017 to 2020, finding seasonal trends and distinct differences in MeHg production between two wetlands on the urban campus of the University of North Carolina at Greensboro. This project investigates the presence of MeHg in invertebrates inhabiting these two wetlands and the surrounding terrestrial forest to quantify the lateral movement of MeHg. Samples of aquatic and terrestrial macroinvertebrates were collected and freeze dried from the wetlands and surrounding forest area using light traps, pitfall traps, and direct sampling. The MeHg content of these samples will be measured by using cold vapor atomic fluorescence spectroscopy (CVAFS). Subsamples were also analyzed for stable carbon (13C) and nitrogen (15N) isotope ratios to characterize energy sources and trophic positions, respectively. We believe the results of this study will inform future management and construction practices of artificial wetlands. The results will provide data on the potential of constructed wetlands to facilitate elevated MeHg concentrations in urban watersheds.