Fish to help gauge health of DuPage River
By Linda Girardi For The Courier-News June 1, 2012 12:44PM
Rod Emmons, a resource technician with the Illinois Department of Natural Resources, nets a couple bass as the Forest Preserve District of DuPage County released 100 4-6 lbs. smallmouth bass in the west branch of the DuPage River at Warrenville Grove Forest Preserve in Warrenville on Wednesday, May 30, 2012. | Steven Buyansky~Sun-Times Media
Updated: June 6, 2012 10:49PM
Olive green fish with dark spots and mottled salt-and-pepper bellies will help biologists determine the health of the West Branch of the DuPage River.
The Forest Preserve District of DuPage County is partnering with the Illinois Department of Natural Resources and Illinois Natural History Survey for a research and monitoring project of sport fish in the river. As part of the project, 100 hefty-sized smallmouth bass were released last Wednesday in areas of the river within the Warrenville Grove Forest Preserve and West DuPage Woods Forest Preserve.
The robust fish swam a short distance and began fanning their fins as if to get acquainted with their new habitat. Some fish swam straight to deeper parts of the river.
The restocking of the freshwater fish comes after a multi-year, $180 million federal environmental cleanup and $25 million restoration of natural streambeds, channels and banks of an eight-mile stretch along Kress Creek and the West Branch of the DuPage River to the McDowell Grove Forest Preserve in Naperville.
The West Branch of the DuPage River was one of four National Priorities List sites that had been contaminated with industrial radioactive thorium.
Years of cleanup work have left the river in much better shape.
At the site of the former Warrenville Grove dam there are now cobbles, rocks and a cascading stream with a backdrop of old forest trees.
“We essentially raised the riverbed and connected the river to the floodplain with plantings,” said Scott Meister, Natural Resources Management coordinator for the forest preserve district. “During times of heavy rain, instead of the river racing through and scouring out the bottom, the water will flow into the floodplain, eliminating erosion and providing better habitat.”
Meister said the removal of the 1930s-era Warrenville Grove and McDowell Grove dams will allow the river to regain a natural course and make it possible for fish to swim upstream.
“Our hope is for the restoration of the river to last for centuries,” Meister said.
In the swim
The release of the bass last Wednesday is an important step in judging how well the restoration work on the river is going. The researchers and biologists from the three agencies involved now will assess the river’s return through the lives of the fish.
Good fishing and a healthy stream go hand-in-hand, said Jeff Stein, fisheries ecologist for the Illinois Natural History Survey.
“We want to see how the fish population reacts to the restoration of the river,” Stein said. “We will be able to assess the population and what parts of the river they prefer.”
Stein said the bass will be easily identifiable by researchers and anglers by their external white or green identification tags. The tags will help provide information about travel patterns and habitat use, and allow for a means to gauge the population. The researchers will collect the data over several years to document how the fish are doing.
Local anglers also will play a role in the project. Researchers will rely on them reporting when a fish with a tag has been caught. The fishermen should call the number on the fish’s tag and then give the tag number and color, date of capture, location and length of the fish to the Illinois Department of Natural Resources.
Anglers are encouraged to release the tagged fish back into the river.
“We are striving for the restoration of the sport fish population — we want to see adult smallmouth bass living, feeding and reproducing in this part of the river,” Stein said.
Stein said a healthy river has a clean habitat, with proper water flow and temperature, as well as a sufficient food supply for fish to thrive.
“A healthy river system will support good sport fishing,” the researcher said.
The researchers said they hope to see the return of sensitive fish, such as the smallmouth bass, thriving with the 25 other species of fish now in the river.