New Zealand mudsnails, an invasive snail previously only found in two Dane County locations, have recently been verified in two new streams — Mt. Vernon Creek in Dane County and Rowan Creek in Columbia County.
Mt. Vernon Creek, located in southwest Dane County, is a tributary to the Western Branch of the Sugar River and is a Class 1 trout stream. Rowan Creek in Columbia County near Poynette is a Class 1 and Class 2 trout stream. Stream biologists and volunteers discovered the snails during routine stream sampling.
The New Zealand mudsnail is an NR40 prohibited invasive species, meaning that it is absent from Wisconsin or found in only a few locations. The small snail can establish large populations that can outcompete native stream insects that serve as food for fish and change the nutrient flows in streams. Click on the following two sentences to access the full story.
All of the locations where New Zealand mudsnails have been found in the state are popular for fishing and may also be used by paddlers, trappers and hikers. Anyone can prevent the spread of invasive species by following the Stop Aquatic Hitchhikers guidance.