Twin Ports Freshwater Folk invites you to their May 6 presentation, "Sinking and Suspended Microplastics in Lake Superior’s Water Column” by Liz Minor, professor at the University of Minnesota Duluth's Large Lakes Observatory and Department of Chemistry and Biochemistry.
In-person attendees are invited to the Duluth MPCA conference room for networking, sandwiches, and plenty of fresh water at 11:30 a.m. The online and in-person presentation will begin at noon. Sadly, the Zoom option is sandwich-free.
This event is free and open to the public. Registration is required for in-person and virtual attendance.
When
Wednesday, May 6, 2026
11:30 a.m. to 1:00 p.m. CDT
Location
Duluth MPCA, conference room
525 Lake Ave. S., Suite 400
Duluth, MN 55802
Parking
Attendees should inform the gate attendant at the MPCA lot that they are attending a meeting at the MPCA.
Registration
- In-person registration
- Virtual registration
Event schedule
- 11:30 a.m. Lunch and networking (in-person only)
- 12:00 p.m. Attendee announcements
- 12:05 p.m. Seminar
- 12:45 p.m. Moderated question and answer session
- Adjourning by 1 p.m. at the latest.
Speaker Bio
Liz Minor is a professor in the department of chemistry and biochemistry and at the Large Lakes Observatory at the University of Minnesota Duluth. She received her B.S. in chemistry from the College of William and Mary in Virginia and her Ph.D. in marine chemistry and geochemistry from the Massachusetts Institute of Technology/Woods Hole Oceanographic Institution joint program in oceanography and ocean engineering.
Her research group studies carbon cycling in lake, river, and ocean water columns across seasonal to decadal scales. This includes work on lake acidification and alkalinity trends and studies of organic matter in aquatic systems, with a focus on its alterations by photochemical and microbial processes. Her lab also studies the new anthropogenic organic matter, plastics. Support for her work has come from the U.S. National Science Foundation, the Minnesota Pollution Control Agency, the state of Minnesota Environmental and Natural Resources Trust Fund, Minnesota Sea Grant, the ACS Petroleum Research Fund, and the U.S. National Park System.
Presentation Abstract
Microplastic concentrations (particles per liter) in the surface waters of Lake Superior are similar to average values in the North Atlantic Ocean. Recent research using in situ pumping shows that microplastic particles exist not only at the surface but throughout the lake water column. This study compares microplastics characteristics in sinking particles from sediment trap samples and suspended particles collected by in situ pump across seasons. Suspended plastic particles showed much lower concentrations and trap samples showed greater microplastic particle fluxes when Lake Superior was stratified. Across all seasons, polypropylene and polyethylene, both of which are less dense than freshwater, were roughly half the sinking particles and two-thirds of the suspended particles. The sinking particles had a more diverse collection of denser polymers, including polyurethane and polycarbonate, and a higher proportion of polyamide than was present in the suspended particles. Results show that the density of the plastic polymer does not appear to be a good predictor for inclusion in sinking vs. suspended particles. The higher plastic sinking flux during the stratified season, rather than concurrent with higher total sediment mass flux, indicates a significant role for biofouling and fecal pellet production as transport mechanisms.
About TPFF
Twin Ports Freshwater Folk (TPFF) is an informal gathering of individuals from the Twin Ports who are involved in freshwater research, policy, or regulatory issues. Meetings take place on the first Wednesday of every month and include networking, informal discussion, and a seminar.
Event Sponsors
- Minnesota Sea Grant
- Great Lakes Toxicology and Ecology Division of the U.S. Environmental Protection Agency
- Minnesota Pollution Control Agency
- Large Lakes Observatory at the University of Minnesota Duluth
- Natural Resources Research Institute at the University of Minnesota Duluth
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Contact
Alex Frie, research and fellowship coordinator, Minnesota Sea Grant, University of Minnesota and University of Minnesota Duluth. [email protected].
Image courtesy of Dan Wilfond.