Zebra mussel infestation leads to boat ban at DuPage County lake

Boating is banned at Deep Quarry Lake in the West Branch Forest Preserve after DuPage County forest officials discovered an infestation of zebra mussels in the water.

The ban will last for at least a year, officials said.

The nonnative mollusks can harm native mussel populations. Prolific breeders, the female zebra mussel can produce between 30,000 to one million eggs per year. A large colony can filter a lake in one day, depriving native species of vital plankton, according to experts.

Some fish and birds eat zebra mussels, but not at a fast enough rate to control populations. The zebra mussel is native to Russia, but experts believe they came over in ballast holds of cargo ships from Europe and infested North American waterways in the 1980s. They also can spread by attaching themselves to the hulls of boats and inside bait buckets, forest preserve officials said.

The zebra mussel infestation was confirmed last month when someone spotted a stick bobbing near the lake's edge that was loaded with the pests. Erik Neidy, the district's manager of natural resources, said further investigation turned up more of the mollusks in the lake.

"Last year, we had a fisherman who sent us a fuzzy picture of what he said were zebra mussels, but we couldn't confirm it," he said.

The West Branch Forest Preserve is south of Army Trail Road near the border of West Chicago and Bartlett. Because the lake feeds into the West Branch of the DuPage River, forest preserve officials have seet up zebra mussel monitoring stations along the river as well as other forest preserve lakes.

Neidy said forest preserve workers have placed plastic plates in Deep Quarry Lake at various depths to determine the level of infestation. The plates are also going in at other forest preserve lakes. Properly permitted boaters still may access Mallard Lake near Bloomingdale, Silver Lake and Herrick Lake near Warrenville as well as Round Meadow Lake near Glen Ellyn.

Neidy said signs warning boaters of the infestation have been posted at all of the district's boating lakes. Some signs warn boaters who may have been out on Deep Quarry Lake already this year to clean their watercraft thoroughly and dry dock it for seven days as a precaution against spreading the pests to other lakes.

Both the state's Department of Natural Resources and Environmental Protection Agency are working in conjunction with the forest preserve to combat the spread of the infestation.