9:00 am - 10:00 am
South Academic Building (SAB) 150, University of Alberta, Edmonton AB
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Jessica Lagroix. This seminar is open to the general public to attend.
MSc with Dr. David Olefeldt.
Zoom Link: https://ualberta-ca.zoom.us/j/94341229701?pwd%3DjcVWw5Q5OFaaHu0X4NlXtMiRPWgXaA.1
Thesis Topic: Methylmercury transformations in peatland-influenced beaver ponds on the Taiga Plains
Abstract:
Beaver ponds have previously been identified as sources of methylmercury (MeHg); a toxic pollutant of global concern due to its bioaccumulation potential and the associated ecosystem and human health risks. However, their MeHg impact in the peatland-rich Taiga Plains is unknown. Are they sinks or sources of MeHg, and what determines their role in this Hg-rich landscape? This study investigates the biogeochemical processes and conditions driving MeHg changes in these ponds. Overall, beaver ponds acted as sinks for MeHg. Net MeHg decreases were linked to longer residence times and high inflow MeHg concentrations, suggesting that photodemethylation is an important driver of MeHg losses. Seasonal patterns in MeHg changes suggest that upstream peatland processes are important drivers of inputs that shape the in-pond processes governing MeHg transformations. These findings reveal the complex interactions between seasonal dynamics, landscape features, and pond biogeochemistry, which together shape mercury transformations and delivery.
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