Recent Trends of Nonindigenous Aquatic Species in the Temperate Regions of North America

Lakes with Zebra Mussels

•Michigan 183 (44)

•Indiana 42 (13)

•Wisconsin 37 (13)

•Ohio 27 (20)

•New York 22 (15)

•Illinois 13 (3)

•Vermont 4 (3)

•Pennsylvania 4 (4)

•Connecticut 2 (1)

•Minnesota 1 (1)

•Virginia 1 (1)

From 1990 through early 2003, 336 lakes have been detected with zebra mussels.

Here is the breakdown by states. The number in parentheses is the number of counties. As you can see Michigan lead by far, but they have a volunteer monitoring program that is finding most of these lakes. I am not aware of similar program in the other states. In states like New York and Ohio it appears that the zms are more widespread. That’s just over 1 lake per county. Not true for Michigan, Indiana, and Wisconsin. They are multiple lakes per county, but then these states probably have a higher concentration of lakes per county.