Zebra Mussel Alert
The barnacle-like zebra mussel poses a multibillion-dollar threat to industrial and public drinking water supplies and may become a costly nuisance to shippers, boaters, commercial fisherman, anglers and beach-goers as well-far more costly in human terms than all previous Great Lakes invaders combined.
Public assistance in reporting zebra mussel sightings at new locations is essential to help its spread to our inland lakes and rivers.
Introduction:
Zebra mussels prefer to settle on hard surfaces when they colonize a water body. Larval zebra mussels (veligers) drift in the water for 3 to 5 weeks before settling & attaching to hard surfaces with their byssal threads. Scientists now estimate that zebra mussels will eventually colonize most of Michigan's inland waters because these lakes reportedly offer mussels the most important environmental conditions (temperature, calcium, pH & food). Michigan Lakes & Streams are interested in learning when adult mussels settle in our inland lakes & streams so they can better understand how to manage this & future invaders.
Tie a 10' length of rope to an ordinary house brick & suspend it as deep as possible but at least 1 foot above the lake bottom. Zebra mussels tend to avoid sunlight. If zebra mussels are present in your lake they will settle on hard surfaces as microscopic larvae & form into adults over the course of the summer. Check the brick surface monthly as Winter approaches. Growth rates vary. Your brick will begin to feel "gritty" when they settle, but young adults will not look much like older adults, which are easily seen with the naked eye. Most adults live 3 to 4 years. Michigan Lakes & Streams at: http://www.mlswa.org/ would appreciate hearing from Michigan lakes whether you find zebra mussels or not. Once they are positively identified in your lake there is no longer a need to drop a brick or monitor.
How to Identify Them
* * Zebra mussels look like small clamswith a yellowish and/or brownish "D"-shaped shell, usually with alternating dark and light bands of color (thus the name "zebra").
* * They can grow up to two inches long, but most are under an inch long. Zebra mussels usually grow in clusters containing numerous individuals (see photo below), and are generally found in shallow (6 to 30 feet deep) algae-rich water.
* * Zebra mussels are the ONLY freshwater mollusk that firmly attaches itself to solid objects, including rocks, boat hulls, etc.
What to Do
* * Note the date and precise location where the mussel or its shell(s) were found.
* * Take the mussel with you (several, if possible) and store in rubbing alcohol (in any case, DON'T throw any back in the water), and
* * IMMEDIATELY call the Michigan Sea Grant Extension Office (517/353-9568) or the Sea Grant agents in western Michigan (616/846-8250), Upper Peninsula (906/228-4830), or eastern Michigan (313/469-6085).
Copyright - University of Wisconsin Sea Grant Institute
