Threats: Examples

Japanese knotweed, once established near along a streambank, can quickly spread downstream creating an impenetrable wall, out-shading all native vegetation. This has occurred on the Sheboygan River and on many others statewide.  If detected early, the spread can be prevented.

Reed canary grass is a well established invasive species.  It has dominated thousands of miles of streambank throughout the state degrading natural habitat.  It serves as a example of the potential invasive species have to outcompete native vegetation and dominate the landscape.

The New Zealand mudsnail is a tiny (1/8 inch) snail that has devastated western streams.  They displace native invertebrates that serve as an important food source for fish.  Providing very little nutrition themselves, they have caused fisheries to decline.  They have been found in Lake Michigan and Lake Superior.  It is important that we detect their migration inland quickly when it occurs and educate fishermen and others to help prevent their spread throughout the state.

Bighead Carp and Silver Carp swim close to the surface of the water and jump in response to boat motors. Boaters, anglers, and others recreating on the water risk severe injury if struck by one of these fish. Bighead carp eat plankton and have the potential to deplete zooplankton populations. That in turn will harm native fish such as paddlefish, bigmouth buffalo, and gizzard shad. They were recently discovered in the Mississippi River near La Crosse.