A study by Illinois researchers provides evidence that the flow of pollutants into the Illinois River decades ago likely drove changes whose effects continue. The Illinois Natural History Survey says it recently found that mussels in the river had larger shells and grew at faster rates during the 20th Century than during the previous 10 centuries.
There are also fewer species. Faster-growing mussels often have shorter life spans, and larger sizes coincide with reduced populations.
In the study, published in the Journal of Science of the Total Environment, researchers point to the 1900 creation of the Chicago Ship and Sanitary Canal as a likely cause. Pollutants flowed down the canal and eliminated most life in the upper Illinois. Conditions are now better but researchers say the mussel changes persist.
