Invasive Species

Invasive plants, animals and disease-causing microorganisms are taking a toll on Wisconsin lakes, rivers, and landscapes – as well as our economy and recreation opportunities. Invasive species can alter ecological relationships among native species and can affect ecosystem function, structure, and economic value. The DNR has been working with citizens and partners to develop ways to prevent and control invasive species. On September 1, 2009, the Invasive Species Identification, Classification and Control rule (also known as Chapter NR 40) went into effect. This comprehensive invasive species law helps us prevent new invaders from getting to Wisconsin in the first place and allows the DNR to move more rapidly to contain new invasives before they are established.

The Newest Invader: Red Swamp Crayfish

Red swamp crayfish, an aggressive, southern crayfish that can decrease native populations of fish, frogs and crayfish, has been found in Wisconsin for the first time in a Washington County pond.

• Taking on the Red Invader [VIDEO Length 3:10]
• Invasive Red Crawfish [VIDEO Length 4:10]

• Fact Sheet: Important information about the Nov. 12 treatment for red swamp crayfish [PDF 303KB]
• Fact Sheet: Red swamp crayfish [PDF 1.09MB]
• Press release: Officials ask citizens to be on the lookout for invasive crayfish
• Press release: New invasive crayfish found in Wisconsin

People who think they have seen or caught the red swamp crayfish in southeastern Wisconsin can contact Heidi Bunk, (262) 574-2130. Elsewhere in the state, people can contact Laura Herman with the University of Wisconsin-Extension (715) 365-8998 or call the DNR hotline, 1-800-TIP-WDNR.