Wisconsin Watch Results Presented

From March 23, 1993 (Update #16)

A summary of the 1992 Wisconsin Zebra Mussel Watch given at the Third International Zebra Mussel Conference focused on four principal findings:

1. Zebra mussels spread to Wisconsin waters of the Great Lakes at a slower rate than anticipated. Larval veliger production increased in 1992 at all Lake Michigan stations, but while settled mussel densities increased in Wisconsin waters of Lake Michigan south of Port Washington, the densities in Green Bay and northern Lake Michigan were similar to those seen in the summer of 1991.

2. Zebra mussels failed to thrive in Superior harbor for the third straight year.

3. Despite the increase in mean veliger densities at all Lake Michigan stations in 1992, colonization by post-veligers was variable in comparison with 1991. Factors that reduced the rate of colonization by zebra mussels in 1992 had less effect on veliger production.

4. The relative timing of peak veliger production and settling on artificial substrates may indicate whether mussels at a given location are produced from local colonies or originate from distant locations.

ID: 19930323-8.

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.