Renae Shewan | ALES Graduate Seminar

Date(s) - 11/04/2024
1:00 pm - 2:00 pm
442B Earth Sciences Building, 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 Renae Shewan. This seminar is open to the general public to attend.

Zoom Link:

MSc with Dr. David Olefeldt.

Thesis Topic: Landscape influences on downstream concentrations of mercury, methylmercury, and dissolved organic carbon in permafrost peatland catchments


Thawing permafrost in peatland regions is likely to alter the landcover and hydrology of impacted catchments, which may increase the transport of neurotoxic methylmercury (MeHg), along with mercury (Hg) and dissolved organic carbon (DOC) to inland waters. However, at the catchment scale the influence of permafrost on downstream concentrations remains unclear. Here we sampled 93 streams across the peatland-rich Taiga Plains to determine the influence of landscape characteristics and climate on downstream concentrations of MeHg, Hg, and DOC. We found that higher mean annual air temperature (a proxy for permafrost extent) and wetland influence were important predictors of higher MeHg and DOC concentrations, while Hg was more influenced by turbidity and the hydrologic conditions of the catchments. Our results indicate that continued climate warming may increase concentrations of MeHg, Hg, and DOC in current permafrost regions and may therefore have implications for the health of aquatic systems and food webs.

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