#21 (June, 1994)

New Sighting
Inland Lake Sighting
Ontario Sightings
Fish Tags Covered with Mussels
Michigan Inland Lake Monitoring Planned
War of the Sponges
Quagga Found in the Ohio River
More Cold Veliger Reports
Mussels Depleting Oxygen in Rivers?

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.