...there are over 150 invasive species in the Great Lakes. These range from fish like the alewife, to plants like the purple loosestrife, to mussels like the zebra and quagga.
...zebra mussels are native to the lakes in southeast Russia. They have been transported to the Great Lakes in the ballast water of ships.
...zebra mussels can produce up to 1 million eggs a year. All of the white in the photo here is from dead zebra mussel shells both in the water and piled up in a long windrow. This was just south of Cross Village, Michigan.
This photo shows a mixture of zebra and snail shells along with stones from the shore of Lake Michigan.