AIS Webinar Series: Mercury Rising: How Zebra Mussels are Changing Fish Contaminants
Thursday, August 21, 1–2 p.m
Register for the Zoom webinar.
Zebra mussels are invasive species that can reshape entire lake ecosystems, with surprising and far-reaching effects. Researchers have discovered that zebra mussels—well-known for clogging pipes and outcompeting native species—may also be quietly increasing mercury levels in popular game fish like walleye and yellow perch. Mercury is a potent neurotoxin that threatens both aquatic life and human health. In lakes invaded by zebra mussels, fish were up to 72% higher in mercury—reaching risky levels at smaller sizes compared to lakes without zebra mussels.
In this webinar, University of Minnesota fisheries ecologist Dr. Gretchen Hansen will explain how zebra mussels are altering where fish feed, how mercury moves through the food web, and what that means for anglers and communities across Minnesota. She'll also share what’s happening now—a new, collaborative effort with state and tribal agencies to build predictive models and create mercury risk maps to help monitor, manage, and potentially mitigate these emerging threats.
Speakers
Dr. Gretchen Hansen is a fisheries ecologist and Associate Professor in the Department of Fisheries, Wildlife, and Conservation Biology at the University of Minnesota. Her research focuses on how environmental stressors—like invasive species and climate change—shape freshwater ecosystems and fish populations. Dr. Hansen works closely with state, federal, and tribal partners to develop research that can identify patterns of change and inform natural resource management decisions. Whether in the classroom, the field, or on a Webinar, she’s passionate about using science to protect the lakes and fisheries that are integral to Minnesota's identity.
We encourage you to join the webinar about 5 minutes early to ensure your links work properly and that you do not have any technical or audio issues.
