Deep Quarry Lake closed
The Forest Preserve District of DuPage County has confirmed the presence of non-native zebra mussels in Deep Quarry Lake at West Branch Forest Preserve in Bartlett.
As a precautionary measure, the district has suspended all boating on Deep Quarry Lake to help slow the spread of the highly invasive species. It is the first sighting in DuPage County of the species. Don LaBrose, fisheries biologist with the Illinois Office of Natural Resources, expects the 40-acre lake to be closed all  summer.

What are they?
The zebra mussel (Dreissena polymorpha) is a fingernail-sized, striped, non-native mollusk. It has spread across the United States by attaching to watercraft and the inside of bait buckets. Zebra mussels are prolific breeders and can critically harm native mussel populations by interfering with feeding.
Large populations can filter all of the water in a lake in one day, consuming plankton that native species rely on for food. Some native waterfowl and fish feed on zebra mussels but do not consume enough to control populations.

What can be done to stop them?
“The main thing is education,” said LaBrose. “We’ll be putting signs up at other lakes in the area, warning of the spread.”
He said the best thing to do is to wash a boat with hot water or a bleach solution to rid the hull and bilge of the pests, but most boaters don’t do that. Boaters should also dump all bait-bucket water into garbage cans before leaving the area, since juvenile zebra mussels cannot be seen by the naked eye.

What will be done to the lake?
LaBrose said the easiest way to rid the lake of zebra mussels is drain it, but that is too expensive.
“A decision has not been made yet, but we probably will use a more-biological approach, introducing more fish that prey on the mussels,” he said. “Overall, the lake is in good shape, and I wouldn’t want to destroy that ecosystem,” he said.
The DuPage County Forest Preserve District is working with the Illinois Department of Natural Resources and the Illinois Environmental Protection Agency to prevent any further spread of the mussels. Because the lake flows into the West Branch of the DuPage River, the district will place zebra-mussel monitoring stations along the river, as well as in other Forest Preserve lakes.

For information
n Individuals with questions regarding boating permits should contact the Forest Preserve District’s Visitor Services office at (630) 933-7248.
Boaters with valid district permits can still use their watercraft on Mallard Lake at Mallard Lake Forest Preserve in Hanover Park, Silver Lake at Blackwell Forest Preserve in Warrenville and Round Meadow Lake at Hidden Lake Forest Preserve in Glen Ellyn.
n For upcoming events and activities throughout the Forest Preserve District, call (630) 933-7200, or visit www.dupageforest.com.