USACE Chicago Crews Conduct Electrofishing Survey on Lake Calumet During 2026 Seasonal Intensive Monitoring; No Invasive Carp Found

CHICAGO — As part of the 2026 Spring Seasonal Intensive Monitoring (SIM) effort, U.S. Army Corps of Engineers (USACE) crews conducted specialized electrofishing operations on Lake Calumet during the week of May 11th. Following intensive sampling at 10 locations chosen to maximize detection within high-probability habitats across the lake, crews reported that no bighead or silver carp were captured or observed during the mission. 10 sites were sampled each day by USACE from May 11th through May 14th.

Bighead and silver carp are aggressive invasive species that outcompete native fish for plankton, posing a severe ecological threat and endangering the Great Lakes' $7 billion commercial and recreational fishing industries. To monitor their presence effectively, biologists rely on electrofishing. This standard scientific survey method applies a specialized, pulsed direct current to the water. The electrical field temporarily stuns nearby fish, allowing crews to safely net, identify, measure, and release them back into the ecosystem unharmed.

The SIM is a critical interagency mission conducted twice a year within the Chicago Area Waterway System (CAWS). It serves as a proactive defense to detect the presence of live bighead or silver carp in areas close to Lake Michigan. Unlike fixed-site monitoring, electrofishing sites for this effort are randomized across broad sections of the waterway to ensure an effective sweep of the CAWS, with sampling occurring from as far north as the North Shore Channel and as far south as the Calumet River.
"We are targeting a diverse range of habitats where invasive carp might seek refuge," said Alex Catalano, USACE Chicago Fish Biologist. "Our findings here, combined with those of our partners, are an important part of confirming that our multi-layered defense strategy continues to be effective."

While no bighead or silver carp were found, the survey confirmed the effectiveness of the monitoring equipment by capturing several other varieties of fish. Species observed and identified during the week included smallmouth bass, yellow perch, pumpkinseed, smallmouth buffalo, rock bass, black crappie, common carp, and round goby.

Currently, the invasive carp population front remains approximately 47 miles from Lake Michigan. The CAWS is protected not only by these rigorous sampling efforts but also by the USACE-operated Electric Dispersal Barrier System in the Chicago Sanitary and Ship Canal (CSSC) in Romeoville, Ill., located 37 miles from the lake. The CSSC barrier acts as a vital, non-structural solution to deter invasive species while ensuring no disruptions to commercial and recreational navigation. Building on this operational success, the upcoming Brandon Road Interbasin Project (BINP) will implement additional complex, multi-layered deterrents further downstream, permanently fortifying the Great Lakes against ecological threats.

The 2026 Spring SIM is led by the Illinois Department of Natural Resources (IDNR) in collaboration with USACE and the U.S. Fish and Wildlife Service. These efforts are part of the Invasive Carp Regional Coordinating Committee’s mission, one of the most comprehensive aquatic nuisance species management programs in North America.