The DuPage County Forest Preserve is monitoring a barrier along the south bank of the Des Plaines River meant to keep out destructive Asian carp, but may also pose problems for other wildlife.
A person using Centennial Trail in Waterfall Glen Forest Preserve near Darien noticed a common snapping turtle with a claw caught in the barrier fence, forest officials said. The barrier was built in 2010 by the U.S. Army Corps of Engineers to reduce the risk of Asian carp being swept from the Des Plaines River and I&M Canal into the Chicago Sanitary and Ship Canal during heavy rains and flooding -- part of an overall project to keep the carp out of Lake Michigan.
John Oldenburg, director of natural resources for the forest preserve, said forest police responded quickly to the report of the turtle.
"The turtle was alive, released and relatively unharmed," Oldenburg said. He added that officers walked a mile and did find other snapping turtles near the barrier but not caught in any way. They also did not spot any of the Illinois-endangered Blanding's turtles that live in Waterfall Glen, nor any of the seven other non-threatened species that live in the forest preserve.
The Des Plaines River barricade consists of concrete barriers and a specially fabricated wire mesh that allows water to flow through but prevents the passage of fish. The barricade extends approximately 13 miles from Romeoville to Willow Springs.
The barrier also includes 20 gates for turtle crossings that were installed approximately 500 feet apart along the Des Plaines Bypass Barrier within the Will County portion last fall, said Sarah Gross, a spokeswoman for the U.S. Army Corps of Engineers.
"(This was) primarily in concern to the Blanding's turtle migration," she said in an email. "Locations of these gates are based on historic migration trends and data, for example, extensive radio-telemetry studies, provided by the Illinois Natural History Survey and the Illinois Department of Natural Resources."
She added that the department also routinely monitors these sites to evaluate whether adjustments need to be made based on migration patterns. And the gates are left open unless there is a threat of flooding.
This was the first time DuPage forest officials found any animal caught in the barrier on its property, Oldenburg said. He added that it might be an isolated instance, but officials are closely monitoring the area to see if any other problems occur.
"We realize there is some biological cost to protecting the Great Lakes and a $5 billion economy," he said. "But if there is a problem, we are going to work toward a solution."