Why does the water in the St. Louis River estuary sometimes look chocolate-brown, coffee-colored, crystal clear or bright green?

Community members are invited to learn more at 6 p.m. Wednesday, April 8, during The River Talks: Why is the Water Green? program at the Lake Superior Estuarium, 3 Marina Drive on Barker’s Island. This event is free and open to the community.

Hannah Nicklay and Addi Knoll of the Lake Superior National Estuarine Research Reserve will offer a behind-the-scenes look at how the health of this vital freshwater ecosystem is monitored. Reserve staff use a combination of high-tech sensors, laboratory analysis and long-term data to understand changing conditions in the estuary.

During the event, attendees will get hands-on experience with water quality sensors, learn what monitoring data reveals about overall water health, and hear the latest research on algal blooms in the estuary.

This program concludes the current season of The River Talks, a free public learning series sponsored by the Lake Superior National Estuarine Research Reserve.