Model Identifies Vulnerable Inland Wisconsin Lakes

From January, 1995 (update #23)

MADISON, Wis. - A predictive model that identifies the 16 inland Wisconsin lakes most likely to be infested by zebra mussels has been developed by UW- Madison aquatic ecologist Dianna Padilla and research associate Mike Chotkowski. Two of the lakes named in the preliminary findings, Okauchee and Elkhart lakes, have already been found to be infested. Mussels have not yet been found in the other 14 lakes identified as susceptible to invasion, most of which were sampled in a cooperative effort this past summer between the Wisconsin DNR and UW Sea Grant Advisory Services specialists. To determine which lakes in the state are most at risk, Padilla used the results of a 1989-1990 boating survey conducted by the DNR. Padilla based her predictive model on the volume of boating traffic between mussel-infested waters - particularly the Wisconsin coast of Lake Michigan and the bay of Green Bay - and inland Wisconsin lakes. She built on previous research showing that trailered boating traffic is a major means of zebra mussel transport from lake to lake. Zebra mussels can survive for several days attached to boat hulls or weeds, or trapped in live wells or bilge water. "Clearly, the more times boats go back and forth between Lake Michigan and some uninfested lake, the greater the chance of that lake getting infested," Padilla said. Padilla said her method can be applied in other states that have similar boater usage data. "Obviously, the state of Wisconsin and the Department of Natural Resources cannot try and stop zebra mussels everywhere," she said. "But if we can predict and target those lakes most likely to first get invaded, we can focus our efforts on making people aware that they are moving these things around."

The 16 Most Zebra Mussel-Prone Lakes in Wisconsin (This list ranks lakes most frequently cited by boaters who also reported using zebra mussel-infested Lake Michigan. Lakes are listed by decreasing rank of traffic volume).

1. Lake Winnebago* 2. Lake Mendota* 3. Pewaukee Lake* 4. Shawano Lake* 5. Wind Lake 6. Nagawicka Lake* 7. Lake Mary 8. Okauchee Lake** 9. Elkhart Lake** 10. Petenwell Lake 11. Clark Lake* 12. High Falls Reservoir* 13. Harpt Lake* 14. Powers Lake 15. Long Lake* 16. Fox Lake*

* Lakes tested for zebra mussels in 1994 by utility, Wisconsin DNR and UW Sea Grant personnel

** Infestations of zebra mussel larvae and/or adults reported in summer 1994.

ID: 199501-9.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.