Long-term Survey and Assessment of Large-River Fishes in Illinois, 2016

Abstract

3EXECUTIVE SUMMARYThis report presents a summary of those data collected during segment 28(2016-17) 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, foursegments or pools of the Mississippi River, and navigable portions of the Iroquois and Kankakee Rivers. In all segments of the LTEF program, all fish species collected were accurately identified, tallied, measured, and weighed. The catchrates of sportfishspecies 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 locationsand sampling periods. Emerald Shiners and Gizzard Shad comprised the majority of the individuals caught, andSilverCarpand Common Carp accounted for the greatest proportion of the biomass collected in most sampling areasof the survey. Futureanalysis of CPUENand PSD trends in sportfish populations sampled by the program may indicate inter-annual recruitment patterns or/andlong-term trends in Illinois sportfish populations.