Long-term Survey and Assessment of Large-River Fishes in Illinois, 2018

This report presents a summary of those data collected during segment 30 (2018-2019) of the Long-term Survey and Assessment of Large-River Fishes in Illinois (LTEF), an annual survey by members of the Illinois Natural History Survey, with funds administered by the U.S. Fish and Wildlife Service and the Illinois Department of Natural Resources. Sampling for the LTEF program was conducted on: six reaches of the Illinois River Waterway and four segments or pools of the Mississippi River. In all segments of the LTEF program, all fish species collected were accurately identified, tallied, measured, and weighed. The catch rates of sportfish species were calculated as the number of individuals collected per hour (CPUEN ± standard error). Structural indices [Proportional Size Distribution (PSD) and Relative Weight (Wr)] were also calculated for several species of interest to regional managers. Catch rates and species varied among all sampling locations and sampling periods. Gizzard Shad and Emerald Shiners comprised the majority of the individuals caught, and Silver Carp and Common Carp accounted for the greatest proportion of the biomass collected in most sampling areas of the survey. Future analysis of CPUEN and PSD trends in sportfish populations sampled by the program may indicate inter-annual recruitment patterns or/and long-term trends in Illinois sportfish populations.U.S. Fish and Wildlife ServiceIllinois Department of Natural Resources, Division of Fisheriesunpublishednot peer reviewedOpe