Editor's Note

From September 10, 1991 (update #10)

Zebra mussels proliferated with vigor in Wisconsin waters of Lakes Michigan since the last Zebra Mussel Update on July 24. Beginning in late July, Zebra Mussel Watch personnel recorded a northerly movement of zebra mussel reproduction during August, starting with sightings of veligers and recently settled post-veligers just above the Illinois border at Kenosha and Racine, and ultimately as far north as Manitowoc. Watch personnel also found the first veligers in Green Bay, Lake Michigan, along with recently settled post-veligers. In Lake Superior, only a few isolated veligers and recently settled post-veligers were observed in Superior Harbor by Watch personnel in August. From July 19 to Aug. 30, zebra mussel larvae (veligers) were detected in nearly 25 percent of 65 harbor and 69 water intake samples in Lake Michigan, and post-veligers were found on about a fourth of the substrate samplers in that lake. During that same period, veligers were found in Lake Superior in 3 of 21 harbor samples and 1 of 9 water intake samples, and post-veligers were found on 2 of 20 substrate samples from Lake Superior.

ID: 19910910-1.

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.