Enhanced Detection of Black Carp in the Lower Illinois River

This report presents a summary of data collected from the 2020-2021 segment of the Enhanced detection of Black Carp in the lower Illinois River, a survey conducted by members of the Illinois Natural History Survey (INHS), with funds administered by the Great Lakes Restoration Initiative (GLRI) and the Illinois Department of Natural Resources (IDNR). Sampling for this project used small and large baited hoop nets, paired side-by-side. This sampling occurred on the La Grange Reach of the Illinois River, the Mississippi River from the Mel Price Lock and Dam downstream approximately 8 river miles, and Horseshoe lake (Alexander County, IL), an Oxbow Lake of the Mississippi River. All fish captured on the Illinois River were identified to species, enumerated, and total length measured to the nearest 10 mm. From September 15-October 31, all fish >100 mm were measured to the nearest mm and weighed to the nearest g. On the Mississippi River and Horseshoe Lake, all fish were identified and enumerated. At all three locations, the bait type used in each hoop net was recorded and associated with the fish caught in each net. Illinois River We sampled the Illinois River from June 15-October 31, 2020, using 105 paired hoop nets baited with clam or cottonseed-based bait. Our most common catches were Bluegill, Channel Catfish, Common Carp, and Freshwater Drum. No Black Carp were captured in the Illinois River during this sampling. Mississippi River We sampled the Mississippi River below the Mel Price Lock and Dam in August 2020 using 67 paired hoop nets baited with clams, cottonseed, soybean, and non-baited nets. Common Carp, Channel Catfish, Flathead Catfish, and Freshwater Drum were our most common catches. One Black Carp was captured in a large hoop net, baited with clams. This effort was in response to several (>20) Black Carp being captured by a commercial fisherman the previous weeks, for the purpose of determining efficacy of various baits for use in hoop nets. Horseshoe Lake We sampled Horseshoe Lake (Alexander County, IL) in May 2021 using 80 paired hoop nets baited with clams, cottonseed, soybean, and non-baited nets. Bluegill, Channel Catfish, and White Crappie were our most common catches. Zero Black Carp were captured using hoop nets, although we did capture one using gill nets upon completion of hoop net sampling. This effort was conducted in response to previous commercial captures of Black Carp in Horseshoe Lake, for the purpose of determining efficacy of various baits for use in hoop nets.