Shellfish decision: Rare mussel holds up repairs to Newburg Road bridge in Belvidere

Ben Stanley
Staff writer

Posted Jan. 7, 2016 at 4:52 PM
Updated Jan 7, 2016 at 7:35 PM

BELVIDERE — For the second time since 2013, a rare mollusk has delayed bridge repairs in Boone County.

The Belvidere Public Works Department's plan to repair concrete, add guard rails and replace expansion joints on the Newburg Road bridge 5 miles west of downtown will have to wait until 2017 while the Illinois Department of Natural Resources determines whether a colony of black sandshell mussels need to be removed from the Kishwaukee River.

"It’s just a delay," said Public Works Director Brent Anderson. "That whole process has to take place during the summer months … so we’re going to lose this construction season."

Anderson estimated the repairs will cost $500,000.

Black sandshell mussels are classified by the DNR as a threatened species in Illinois rivers. Native mussels like the black sandshell are natural water filters for river systems, filtering out diatoms and green algae. Their shells and even their waste are vital to river ecosystems.

"It affects water clarity when they die," said mussel expert Lisie Kitchel, a DNR conservation biologist. "These guys are really the kidneys, or filters, of the whole river system."

Mussels, particularly black sandshells, are very sensitive to water quality. They are one of the first species to go when rivers become polluted and one of the last to return when water quality improves.

Kitchel said the black sandshell population in northern Illinois is rebounding, but slowly.

"The fish come back first, then the insects ... and eventually the crayfish and last are the mussels," Kitchel said. "For rare species it takes longer to recover."

Kitchel said that until mussel populations rebound, a river system hasn’t returned to full health.

This isn't the first time a rare mussel has halted bridge repairs. In February 2012, a portion of a beam on the Orth Road bridge in Timberlane collapsed. While local officials intended to repair the bridge in 2013, the project was delayed for more than a year while state officials searched a small creek beneath the bridge for spike mussels.

Ben Stanley: 815-987-1369; bstanley@rrstar.com; @ben_j_stanley

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