New Sightings in Wisconsin

From April 30, 1991 (update #7)

STURGEON BAY - A single, 1-inch (25 mm) zebra mussel was found attached to a rock in 12 feet (3.65 m) of water here April 28 by Bruce Lutz, one of 16 volunteer divers from a commercial dive team at the Inland Seas Diving Academy, Neenah, who spent the afternoon searching the waters of Sturgeon Bay. The discovery followed a morning workshop in zebra mussel identification techniques conducted by Zebra Mussel Watch Coordinator Clifford Kraft and Assistant Coordinator Jory Jonas on the University of Wisconsin-Green Bay campus. Both Kraft and Jonas were on hand when the mussel was brought to shore, confirming the first sighting of a mussel living in the waters of Sturgeon Bay. Mussels were regularly observed during 1990 attached to ships at two local shipyards.

KEWAUNEE - Thirteen zebra mussels were found April 20 in the circulating water system of the Kewaunee nuclear power plant by Wisconsin Public Service Corporation employees making an inspection of the system while the plant was shut down for refueling. Twelve of the mussels were found in a low-flow, dead-end area of the water system. A single isolated mussel was found in the circulating water system at another location in the plant. The sightings were made by plant personnel recently trained in mussel identification by Zebra Mussel Watch Assistant Coordinator Jory Jonas, who was called to the plant to confirm the sighting. The plant's intake piping and service water system were also thoroughly inspected during this scheduled shutdown.

RACINE - Ten mussels were found April 14 in a 54-inch (137 cm) intake near a shore well at the Racine Water Utility, according to Superintendent Herb Schmidt. The mussels were found during a temporary plant shutdown in which the inspected intake was dewatered to allow Schmidt and other plant personnel to get a firsthand look. The mussels were 0.3-0.9 inches (8-23 mm) in length.

SHEBOYGAN Two 0.7-inch (20 mm) zebra mussels were found on a pump housing at Wisconsin Power & Light's Edgewater Generating Station here in late April, according to Production Engineer Dan Everson. This is the same facility at which three zebra mussels were found in two sightings last fall.

MANITOWOC - Two zebra mussels were found in a condenser of the Manitowoc Public Utilities southside power plant Feb. 21 while one generator was down for routine maintenance. One of the mussels was 1.2 inches (30 mm) in length - at the large end of the reported size range for zebra mussels. It was located in a chamber that could only be reached by passing through tubes smaller than its diameter, indicating that it grew while in the power plant. Two other condensers serviced at the same time showed no signs of zebra mussels. Plant workers reported that the condenser had been last serviced three years ago.

SUPERIOR - Four buoys from the Superior-Duluth harbor were reported as having "light" zebra mussel infestation in a U.S. Coast Guard summary report on positive zebra mussel sightings from navigation buoys decommissioned during winter 1990. The summary also included buoys from Lake Erie, Saginaw Bay, the Detroit River and the Niagara River. The summary was prepared by the commander of the Ninth Coast Guard District in Cleveland.

ID: 19910430-2.

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.