Reservoirs, Lakes, and Rivers

Reservoirs, lakes, and rivers (in low velocity areas) are all subject to infestation by quagga and zebra mussels. Hard substrates at viable depths for mussels, such as rocks, concrete infrastructure, and other organisms, may be significantly fouled. Dock pilings and floats are also targets of fouling, which may weigh down and sink floating docks. Quagga mussels can also inhabit soft muddy bottom areas. Dead mussels often raft on shorelines, impacting recreationists due to their sharp edges and bad odors.

Reservoirs often have large annual level fluctuations. The level changes can sometimes be used to assist in controlling the amount of mussel infestation through a few days of desiccation during the normal level changes. Floating structures within a reservoir need to be inspected as they will change level with the reservoir and attached mussels can inoculate the reservoir when the levels increase.

Zebra Mussel Shells on the Shore of Lake Winnebago, Wisconsin (photo by Andrew Sabai)