The mussels have become major problems in the U.S. since they were accidentally introduced in 1988. The fingernail-sized mussels can tolerate a wide range of environmental conditions, and reproduce prodigiously (30,000 to 70,000 per square yard). They can clog intake pipes of water treatment and power plants, as well as boat engine cooling systems, and by filtering plankton from the water, they can significantly increase water clarity and change the ecological structure of a lake's community.

Zebra mussels cling to flat surfaces, so samplers have been developed that offer them choice accomodations in four-level "mussel condos" consisting of four sheets of plexiglas in graduated sizes held together with an eye bolt. Volunteers tie the bolt to a line then lower the sampler into the water. By checking for newcomers to the neighborhood every month, they can get early warning that the mussels have arrived, and an estimate from the numbers of how serious the infestation is.

So far, no commercial firm has the samplers available for sale. Ron Kruger, who teaches woodworking and shop classes at Lanphier High School, heard about the need for the samplers from a neighbor who works at the Illinois EPA, and offered to have his students help out.

The Agency provided the plexiglas, and in a couple of weeks the students got some hands-on experience using the materials to produce 800 graduated sheets -- enough to make 200 samplers. The Agency will provide the plates, bolts and screws to the volunteers in its Volunteer Lake Monitoring Program, and they will assemble the samplers and place them.

In recognition of their contribution to lakes around Illinois, the students and their teacher were presented with a certificate of appreciation from the Illinois EPA.

Students at Lanphier High School in Springfield, Ill., inspect a completed zebra mussel sampler made from plexiglas sheets they cut and drilled as a class project. From left are Derek Birdwell, Nicholas Heitzman, Michael L. Friarson, Woodworking Instructor Ron Kruger, Michael Shoemaker, Thomas King and Jason Flynn. The plates they cut will provide 200 finished samplers.