Paul Gabriel will defend the thesis "Measuring Volcanic Gaseous Elemental Mercury in Katmai National Park, and the Watershed Dynamics that Regulate Aquatic Uptake" on April 17.

Katmai National Park and Preserve is vast, pristine, and remote. Despite this, water quality monitoring has identified several lakes containing resident fish with mercury concentrations above state and federal guidelines for human consumption. Previous work by the National Park Service has identified the source of mercury to be natural and likely tied to volcanic activity, with lakes closer to volcanism having higher fish mercury levels than those further away. This project builds on past work by sampling volcanic gases for mercury, a first in the state of Alaska. We then built a dispersion curve to estimate atmospheric mercury levels by watershed and estimate local atmospheric transportation of mercury. Mercury loading however is not the entire story, as proper conditions in individual watersheds need to exist for mercury to undergo methylation and enter the food web. We found a relationship between watershed residence time and methylation potential in the lakes of Katmai, allowing us to use water isotopes as a tool to identify methylation potential.

Event location - CPISB 105A
Event date - April 17, 2025
Event start time - 3 p.m.
Event end time - 4 p.m.

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