In late August, 173 volunteers waded in or trekked along the shorelines of over 100 rivers and lakes across Wisconsin, embarking on a search for aquatic invasive species as part of River Alliance’s Snapshot Day. River Alliance hosted the very first Snapshot Day in 2014, in partnership with the Wisconsin Department of Natural Resources. The event was organized to detect invasive species entering Wisconsin rivers through pathways related to human access, with bridges being a key focus.

Since then the program has grown to include a partnership with UW-Extension and expanded its focus to include lakes and other sites. Volunteers and local partners join up to help prevent the spread of invasive species that harm rivers, lakes and wetlands. The statewide “citizen-science” approach helps maximize the number of sites being checked.

A total of 153 different sites were visited across Wisconsin during this year’s event, with volunteers helping to identify 20 previously undocumented populations of restricted invasive species. Volunteers also helped confirm the presence of six previously observed, but unverified species.

Data from the event will be added to the DNR’s Surface Water Integrated Monitoring System and will be used to help guide management and prevention efforts. Statewide results will be posted on the River Alliance of Wisconsin website and the Wisconsin DNR’s SWIMS database.