Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage-specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year-class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment

Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage-specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year-class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment

Upper Mississippi River fish population monitoring and sport fish assessment in west-central Illinois, 2019

This report presents a summary of data collected during segment 06 (2019-2020) of the Upper Mississippi River fish population monitoring and sport fish assessment in west-central Illinois, an annual survey by staff 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 program was conducted on 6 navigational pools of the Upper Mississippi River. All fishes collected were accurately identified, counted, measured, and weighed. The catch rates of several key species were calculated as the number of individuals collected per hour (CPUE ± standard error). Proportional size distribution (PSD) was also calculated for several key species. Catch rates and species varied among all sampling locations and sampling periods. Emerald Shiner and Gizzard Shad comprised most the individuals caught, and Common Carp and Smallmouth Buffalo accounted for the greatest proportion of the biomass collected. Sportfish Catch rates and sizes of popular sportfish species varied greatly among the navigation pools sampled during 2019. Bluegill and Channel Catfish were the most-abundantly collected sportfish species in nearly all areas along the Upper Mississippi River, although Largemouth Bass and Smallmouth Bass also appear to have robust populations. The slow but steady increase in White Bass CPUE since 2012 may warrant further investigation. Our long-term datasets allow us to observe substantial annual variations in the relative abundance and size distribution of many sportfish species, like Smallmouth Bass and White Bass. These observations could serve as a catalyst for future research investigating the effects environmental changes and management policies on the sustainability of Illinois’ sportfish populations. Invasive Species Although the main focus of the F-193-R project is to conduct monitoring to improve our understanding of population dynamics, life histories, and habitat requirements of sportfishes, the program’s sampling strategies are also useful for documenting trends in the relative abundance of non-native species occupying Illinois’ large river ecosystems. Our surveys suggest Common Carp populations are declining across the region since 2009, which may be the harbinger of good things to come for native fish populations that have been negatively affected by Common Carp. Alternatively, Silver Carp populations (below L&D 19) appear to be increasing since 2012, which may counteract any benefits native fish populations may have gained as a consequence of declining Common Carp populations. We advise that researchers be aware that our sampling protocols (e.g., restriction to main-channel habitats) may limit our probability of encountering the greatest densities of invasive species.Illinois Department of Natural Resources, Division of FIsheriesU.S. Fish and Wildlife Service Project F-193-R Segment 06unpublishednot peer reviewedOpe

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

Over 50 years of fish community monitoring in Illinois’ large rivers: The evolution of methods used by the Illinois Natural History Survey’s Long-term Survey and Assessment of Large-River Fishes in Illinois

Federal Aid in Sport Fish Restoration Act (F-101-R), administered by the U.S. Fish and Wildlife Service and Illinois Department of Natural Resourcesis peer reviewedOpe

The long-term Illinois rivers fish population monitoring program 2014

This report presents a summary of those data collected during segment 26(2014-15) of the Long-term Illinois Rivers Fish Population Monitoring Program(LTEF), an annual survey executed 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, six segments or pools of the Mississippi River, and navigable portions of the Iroquois and Kankakee Rives. 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 species of interest to regional managers. Catch rates and species richness varied greatly among all sampling locations and sampling periods. Emerald Shiners and Gizzard Shad 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. The analysis of CPUEN and PSD trends in sportfish populations sampled by the program may indicate inter-annual recruitment patterns in sportfish populations around the state. Both Shovelnose Sturgeon and Blue Catfish were the two species most commonly encountered in the gill net surveys.IDNR Division of Fisheries Project F-101-R, Segment 26unpublishednot peer reviewe

Estimating population size of largemouth bass and black crappie at The Nature Conservancy's Emiquon Preserve prior to reconnection to the Illinois River

Prior to completion of the water control structure at The Nature Conservancy’s Emiquon Nature Preserve (Emiquon), a mark-recapture study was conducted on largemouth bass Micropterus salmoides and black crappie Pomoxis nigromaculatus to estimate the populations of both species. Largemouth bass > 150 mm and black crappie > 100 mm were captured using pulsed-DC electrofishing, fyke nets, and tandem fyke nets and double tagged using T-bar style clear tags. Results of this study show very large populations of both species, with populations of largemouth bass estimated at 21,090 (17,110-27,484) and black crappie estimated at 205,042 (91,198-490,563). Information gained in this study will allow Nature Conservancy managers to make informed decisions on future management actions and allow for potential evaluation of those management actions on two major components of the recreational fishery at Emiquon.Ope

Long-term Survey and Assessment of Large-River Fishes in Illinois, 2017

This report presents a summary of those data collected during segment 29 (2017-18) 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, four segments 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 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/andlong-term trends in Illinois sportfish populations.Federal Aid in Sport Fish Restoration project F-101-Runpublishednot peer reviewe

Long-term Survey and Assessment of Large-River Fishes in Illinois, 2015

This report presents a summary of those data collected during segment 26 (2014-15) of the Long-term Survey and Assessment of Large-River Fishes in Illinois (LTEF), an annual survey executed 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, six segments 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 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 species of interest to regional managers. Catch rates and species richness varied greatly among all sampling locations and sampling periods. Emerald Shiners and Gizzard Shad comprised the majority of the individuals caught, and Silver Carpand Common Carp accounted for the greatest proportion of the biomass collected in most sampling areas of the survey. The analysis of CPUEN and PSD trends in sportfish populations sampled by the program may indicate inter-annual recruitment patterns or long-term trends in sportfish populations around the state. Shovelnose Sturgeon was the species most commonly encountered in the gill net surveys; sampling was substantially reduced during the 2015-2016 winter season relative to previous years due to moderate to major flooding during the majority of the field season.IDNR Division of Fisheries U.S. Fish & Wildlife Service F-101-R, Segment 27unpublishednot peer reviewe