Ecological Impacts

From October, 1995 (Update #25)

Data on fish abundance and growth rates has shown no conclusive trends related to the presence of zebra mussels, according to The Lake Erie Fisheries Report, prepared by the Ontario Ministy of Natural Resources for the Great Lake Fishery Commission's Lake Erie Committee meeting last March. According to the report, the mean 1994 chlorophyll-a concentrations in the Canadian waters of Lake Erie increased to pre-invasion levels due to large blooms of blue-green algae (especially Microcystis aeruginosa) which persisted from August to October. Similar blooms have been observed in mussel-infested Saginaw Bay, Lake Huron, and Oneida Lake. A decline in zooplankton has been observed every year since 1989 compared with zooplankton data collected in 1971, 1972 and 1988. The decline is due mainly to reduced numbers of rotifers and copepod nauplii.

ID: 199510-5.

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.