New Sighting

From June, 1994 (update #21)

ANN ARBOR, Mich. -- Two zebra mussels were found in late April at Portage Lake by Renee Sherman, a graduate student at the University of Michigan. Sherman found the large mussels -- 20 and 16 mm in length -- attached to rocks while she was surveying the lake bottom for native Unionid mollusks. No veligers were found in a June 1993 plankton sample collected from Portage Lake by Paul Marangelo, a Michigan Sea Grant-supported biologist who helped conduct the 1993 Michigan inland lake monitoring program. (Marangelo also searched for settled zebra mussels attached to macrophytes in Portage Lake, but didn't find any.) Marangelo said he expects more zebra mussels will be found in this lake, which has a public boat landing that receives "moderately heavy" recreational use. Further plankton samples and mussel surveys will be conducted this summer.

ID: 199406-1.

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.