Twin Ports Freshwater Folk: Mercury Cycling in the St. Louis River: How New Tools are Deciphering Legacy Mercury Contamination

Twin Ports Freshwater Folk: Mercury Cycling in the St. Louis River: How New Tools are Deciphering Legacy Mercury Contamination
12/7/22, 11:30 am - 12/7/22, 1:00 pm

Registration:

Please register in advance to attend this free event. Subscribe to the Twin Ports Freshwater Folk (TPFF) email list for news and updates.

Description:

Mercury (Hg) contamination within the St. Louis River estuary (SLRE) is of long-term concern because fish Hg concentrations are elevated above human health and wildlife guidelines.

In this presentation, Sarah Janssen, research chemist for the Upper Midwest Water Science Center of the U.S. Geological Survey will discuss Hg concentrations in SLRE sediments are higher than those observed elsewhere in the region, and game fish Hg concentrations in the estuary are double that of Lake Superior. It is unclear to what extent industrial Hg, from legacy contamination, within the SLRE contributes to these high Hg concentrations in fish. To understand the relative contributions of legacy versus contemporary Hg contributions (e.g., atmospheric deposition or land runoff), we used Hg stable isotopes to identify these Hg sources within the SLRE. Using these new tools allows us to assess the contribution of different mercury sources and determine how they impact fish tissue mercury levels.

TPFF webinars are for people in the Twin Ports communities of Duluth, Minnesota and Superior, Wisconsin, and anyone engaged in freshwater research, policy, or management. TPFF meetings are the first Wednesday of every month and include networking and informal discussion followed by a presentation(s) on a freshwater topic.

Event Schedule:

11:30 a.m. Meet-and-greet breakout sessions

12:00 p.m. Announcements by attendees

12:05 p.m. Seminar(s)

12:45 p.m. Moderated question and answer

1:00 p.m. Adjourn

Guest Speakers:

Sarah Janssen, research chemist, Upper Midwest Water Science Center, U.S. Geological Survey, sjanssen@usgs.gov.

Contact:

Minnesota Sea Grant Research and Fellowship Coordinator, Alex Frie, afrie@umn.edu.

Image credit: Sarah Janssen