New Invasive Crayfish Found In Wisconsin

“This is exactly what the Natural Resources Board and the Legislature expected us to do with this rule: respond to citizen reports of new invasives, check it out, and if it’s on the prohibited list, get out there as quickly as possible develop a containment and control strategy,” said Department of Natural Resources Secretary Matt Frank.;

“If we can get on it quickly, we have a much better opportunity to eradicate new introductions from the state.”

The red swamp crayfish (pdf; 1.09MB), found by a citizen Aug. 25, 2009, in a Washington County subdivision pond, is prohibited under the new rule that took effect Sept. 1, 2009, and which gives the DNR authority to take fast action to eradicate prohibited species.

The crayfish was confirmed Aug. 26 by Milwaukee Public Museum experts as a red swamp crayfish, a Louisiana native raised by southern aquaculture operations, often sold to school teachers for their classrooms and to restaurants. This marks the first time the crayfish has been documented in Wisconsin, and its arrival is of particular concern because it reproduces prolifically and can move overland, increasing its chances of spreading on its own.

Since the discovery of the crayfish, DNR fish biologist Sue Beyler and aquatic invasive species staff have been setting traps and surveying nearby waters to determine whether it’s a reproducing population and whether the crayfish have spread, important information for eradicating it. They are developing a control plan that will explore options such as trapping and chemical treatment to eradicate the crayfish, and also developing a long-term monitoring plan for area waters.

Signs have been posted around the pond to alert boaters, anglers, and other potential users of the park where the pond is that the invasive species is present and that it’s illegal to move live crayfish from the pond.