Increased fishing quality of Chicago's waterways following the Clean Water Act

As conditions of Chicago's (Illinois, USA) waterways improved following implementation of the Clean Water Act, interest in recreational use of the waterways continued to grow, but the ability of this system to support quality recreational fishing opportunities remained unclear. We analyzed historical electrofishing data (1985–2020) to determine the status and trends in body-size metrics of fish populations throughout Chicago's waterways. Many species exhibited increases in abundance, size, and diversity of lengths. Despite these increases, the number of quality-sized or larger fish was sparse. While many species increased in abundance, Common Carp (Cyprinus carpio) and Gizzard Shad (Dorosoma cepedianum) declined in abundance during 2001–2020. Improvements to the availability and diversity of key habitats within Chicago's waterways would likely improve target fish demographics further and resultant recreational fishery opportunities.