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Macroinvertebrate Update Title Page
Yearly summaries

Zebra Mussels

There was an extensive die-off in zebra mussels in Pools 8 and 13 (Table 2) in 2003 (Figure 5). Large numbers of dead zebra mussels were found in the samples. The few live zebra mussels found were small (<1 cm). Although the die-off was extensive, there were reports over the summer of small zebra mussels on aquatic vegetation, boats, and docks; thus, 2003 may have been a good year for recruitment. The die-off may be part of a demographic shift. Zebra mussels only live 4–5 years and our data from 1999 and 2000 indicate that large year classes of zebra mussels were produced in these pools 4–5 years ago. Thus, this may have been a natural die-off of older zebra mussels. Other potential causes include parasites, water flows, or water temperature changes in fall/winter 2002.

Photo: Jennie Sauer, Upper Midwest Environmental Sciences Center

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Content manager: Jennie Sauer

Page Last Modified: April 17, 2018