New Sightings in Wisconsin

From October 26, 1990 (update #5)

SHEBOYGAN - Two half-inch-long zebra mussels were found Oct. 16 attached to a metal frame in the screen house of Wisconsin Power & Light's Edgewater Generating Station. The intake bringing water into this area is located 1,420 feet offshore at a 10-foot depth. The frame had been pulled out of the water for repair, and an alert mechanic noticed one mussel next to a bolt that he was about to replace. The frame and accompanying screens had already been hosed off prior to this find, making it difficult to determine the extent of mussel infestation. Except for those found attached to ships, this is only the second time zebra mussels have been found growing in Wisconsin waters of Lake Michigan, and it is the farthest north the mussels have been found in the lake.

SUPERIOR - Wisconsin Zebra Mussel Watch scientists continued to find more evidence of infestations in Superior-Duluth harbor. On Sept. 24, five zebra mussels, ranging in size from 0.04 to 0.09 inches, were found on substrate samplers that had been placed in the harbor in May and July. Ten recently settled zebra mussels, ranging in size from 0.03 to 0.08 inches, were found Oct. 5 on samplers placed at the Western Lake Superior Sewerage District.

STURGEON BAY - Once again, adult zebra mussels were found in the sea chest of a commercial ship undergoing inspection while in drydock. In late September, a U.S. Coast Guard inspector reported finding mussels on the Paul H. Townsend, a cement carrier that he noted had been in Lake Erie about five times during the past year. Earlier in the month, large numbers of mussels were found in the sea chest of the Coast Guard vessel Acacia, which is based in Cheboygan, Mich., at the north end of Lake Michigan.

ID: 19901026-2.

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.