Editor's Note

From December 17, 1993 (update #19)

Zebra mussels were found throughout the Wisconsin waters of Lake Michigan this summer, most dramatically in a long-expected explosion in the bay of Green Bay in July. By late fall hundreds of zebra mussel sightings had been reported along Wisconsin's Door County shoreline.

There were only a few signs of zebra mussels in Lake Superior this year. A single mussel was found on a substrate sampler retrieved in late October from Superior Duluth Harbor, and low-to-moderate numbers of mussels were observed by divers in November. No zebra mussels were found on 109 other substrate samples, nor were any veligers found in 46 plankton tows collected from the harbor. From late May through mid-November, veligers were detected in 178 of 230 (77%) plankton tows and 94 of 153 (61%) substrate samples collected from Lake Michigan. No zebra mussels were found in the 43 plankton tows taken from Lake Winnebago this summer. So far, there have been no confirmed sightings in Lake Winnebago.

Perhaps the year's biggest news occurred in late August when recently settled zebra mussels were discovered at a Dairyland Power Cooperative hydropower facility on the Chippewa River near Ladysmith. This was the first inland sighting of mussels in Wisconsin other than in the Mississippi River. Follow-up surveys have found no additional zebra mussels at the location.

ID: 19931217-1.

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.