Statewide Snapshot Day

Snapshot Day was Saturday, August 21, 2021


A group of volunteers gather for a photo in a wooded area near Madison's Cherokee Marsh
A group of Snapshot Day volunteers gather for a photo in a wooded area near Madison’s Cherokee Marsh.

Twenty two events welcomed 105 participants who monitored 128 sites for aquatic invasive species.

Volunteers found 103 reports of 17 different species of aquatic invaders, including 24 new populations reported. The top three most common reports were of purple loosestrife, Eurasian watermilfoil and curly leaf pondweed.

Thank you to all of the volunteers and site coordinators for making the 8th annual Snapshot Day so successful!

The next Snapshot Day will be on August 20, 2022.

About Snapshot Day

A woman holds up a Snapshot Day poster
A volunteer smiles while holding up a Snapshot Day poster.
Snapshot Day is Wisconsin’s largest community science event for monitoring aquatic invasive species and contributes a huge amount of data for the Wisconsin Department of Natural Resources database.
The event has led to the early detection of new invasive species or new waterbodies impacted, and has helped to inform future management plans. This event is made possible by a partnership among River Alliance of Wisconsin, Wisconsin DNR, UW Extension, and dozens of local partners that help to host sites across the state.
To see the kinds of activities that happen on Snapshot Day, here is a great story map from the 2019 event about the volunteers’ activities.


2021 Snapshot Day overview
2021 Snapshot Day monitoring protocols for volunteers

Snapshot Day is coordinated in partnership with Wisconsin Department of Natural Resources, University of Wisconsin-Madison Division of Extension, over 20 partners, and volunteers like YOU!