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Research about Illinois River

Source-linked reports with geographic coverage including Illinois River.

At least 19 recordsLinked to original sources
USGS2026

Understanding co-invading species’ ecological strategies and interactions with causal inference and simple dynamic models: Bighead (Hypophthalmichthys nobilis) and Silver carp (H. molitrix) in the Illinois River, USA

Species interactions among multiple invasive species can present hidden challenges for management and eradication efforts. Bighead and Silver carp ( Hypophthalmichthys nobilis and H. molitrix , respectively) are closely related species that have co-invaded the Mississippi River and many of its tributaries, including the Illinois River. We used a combination of causal inference and dynamic models to test for interspecific interactions in a 10-year data set of hydroacoustic density data from the Illinois River. The results suggest that Bighead and Silver carp are exploiting different ecological strategies; where Bighead carp shows fast initial growth but low equilibrium density and Silver carp had a lower low-density growth rate but larger equilibrium population density. Further, we found evidence for a positive interspecific effect of Silver carp on Bighead carp. The mechanism leading to the observed positive interactions is unknown, but could be an effect of ecological facilitation, differential responses to harvest of both species, or hybridization and introgression. Finally, while these results provide valuable information in the ecological strategies and relationships between these species, simulations of the resulting models suggest that the magnitude of the positive interaction is likely too small to be exploited for innovative multispecies management interventions.

Illinois↗
USGS2026

Seasonal environmental conditions and river morphology shape summer phytoplankton communities

1. Phytoplankton form the base of large river food webs but there are limited studies on the nature and drivers of communities over longer time scales. Further, climate change is projected to favor taxa associated with harmful algal blooms, but our knowledge of the timing, locations, and drivers of cyanobacteria in rivers lags that of lakes and marine environments. 2. We used a summer phytoplankton community dataset collected from 2010-2020 across main channel, side channel and backwater areas in the La Grange reach of the Illinois River to assess: 1) How much do summer phytoplankton communities across diverse aquatic areas within a large river vary from year to year?, 2) What environmental conditions are associated with that variation?, and 3) Do cyanobacteria respond differently than the full phytoplankton community? 3. We found greater differences in phytoplankton communities across years than among aquatic areas. Further, we showed that annual variation in phytoplankton communities was synchronous among taxa in the same aquatic area, rather than specific to each taxonomic group or taxa-area combination. After accounting for this spatial variation in annual dynamics, phytoplankton reflected river conditions across seasons, responding positively to summer total phosphorus and invasive carp abundance and negatively to winter discharge and spring silica to nitrogen ratio. Annual variation in cyanobacteria was similarly distinct among main channel, side channel and backwater areas but was best explained by the ratio of summer air temperature to discharge, representing conditions that favored growth over transport. 4. These results show that annual variation in summer phytoplankton and cyanobacterial communities both reflected the spatial diversity of the river landscape and responded to conditions that occurred at different spatial and temporal scales. Further, in this highly modified river basin, we showed that a mix of anthropogenic pressures including eutrophication, invasive species, and potential changes to winter and spring conditions affected the phytoplankton communities present in the summer. Thus, when evaluating long-term change and the potential for harmful algal blooms in rivers it is important to consider spatial diversity of phytoplankton communities, how their sensitivity to environmental change may vary across the river landscape, and the suite of human modifications acting on those communities.

Illinois↗
USGS2025

Spatial variation of eDNA detection across an invasion gradient for invasive species monitoring programs

Spatial and temporal distribution data provide critical information for invasive species management. For example, distribution data can help managers with early detections and guiding other response actions. Environmental DNA (eDNA)-based sampling exists as one tool for monitoring invasive species. As part of bigheaded carp Hypophthalmichthys spp. monitoring efforts in the Illinois River, USA, we compared eDNA-based sampling results at multiple habitats across an invasion gradient in 2015. Greater densities of carp occurred downriver in the Illinois River and lower densities occurred upriver. We sampled from five locations along this gradient and from three habitat types (backwater, main channel, and shoreline) within each location. We sampled each location in April and June. A priori , we hypothesized that more eDNA detections would occur downriver, where higher densities of carp occur; that more eDNA detections would occur in backwater habitats compared to areas of the river with more fish movement; and that more eDNA detections would occur in April, because bigheaded carps are thought to use our sampling areas more during the spring. We compared the proportion of samples positive across this gradient, the habitat type, and the two sampling time periods. The most downriver location had the highest proportion of samples with eDNA detections, the backwater habitats had the highest proportion of samples with eDNA detections, and April had more positive detections than June. Our results highlight the importance of sampling across multiple habitat types and across time to gain a clear understanding of distribution when using eDNA-based sampling. Thus, being cognizant of the interactions between seasonal habitat use and eDNA-based detections is important for managers who rely upon eDNA-based monitoring.

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USGS2024

Applying local and global sensitivity analysis to inform bigheaded carp management

Natural resource managers commonly use population-level models to aid in understanding the status of target populations or the potential implications of management actions. Sensitivity analyses, specifically, local sensitivity analysis (LSA) and global sensitivity analysis (GSA), exist as tools to improve understanding of these models, the importance of specific parameters to model outcomes, and the assumptions inherent to population models. However, applied ecology and closely related fields such as fisheries and wildlife management rarely use LSA or GSA. Here, we apply LSA and GSA to the Spatially Explicit Invasive Carp Population model, a population-level model used to simulate and compare management actions on the invasive silver carp Hypophthalmichthys molitrix population in the Illinois River. The spatial structure within the model arises from the navigation “pools” that exist between navigation lock-and-dam in the river and are also the focus of fisheries management in the river. We completed LSA and GSA for two reasons: (1) to compare the importance of model input parameters on simulated model populations and (2) to demonstrate the use of LSA and GSA for population-level models. In our system, the most important sensitivity values generally were detected in Alton Pool. This pool is the farthest downstream and includes a direct connection with the Mississippi River. These results indicate that the population dynamics in Alton Pool are an important driver of the population dynamics throughout the Illinois River. Management outcomes in this system will, therefore, be strongly dependent on the dynamics of Alton Pool.

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USGS2024

Multi-scale effects of behavioral movement deterrents on invasive carp metapopulations

Behavioral deterrents of among-pool movement represent a promising tool for controlling invasive fish populations. To date, much of the research in this area has been focused on the direct effectiveness of different methods of deterrence. However, the effect of these structures on populations in spatially complex habitats is unknown. We combine a metacommunity model with movement data of two invasive species (bighead carp and silver carp) in a large river to assess local and river-wide scale population outcomes of deterrent locations. We calculated (1) which potential deterrent locations are most effective at reducing the growth at the invasion front (2) the river-scale population effects at each location, and (3) what, if any, are the risks imposed by altering the current spatial dynamics. We found that the effects on the population dynamics at the invasion front varied with the location of deterrents, ranging from near zero to effects equal to the reduction in an individual’s movement across the deterrent. The river-scale population growth rate was slightly increased by all potential deterrent placements because the deterrents tended to concentrate more of the river-scale population into pools with the highest recruitment rates. The short-term, transient dynamics followed a strictly decreasing pattern after deterrent placement suggesting no additional short-term risk. These results suggest that deterrents can be an effective and low-risk intervention for the control of invasive carp, although the population level effect will depend on the interaction of the traits and behavior of the species with the physical character and spatial structure of the habitat.

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USGS2024

Comparing maximum likelihood and Bayesian methods for fitting hidden Markov models to multi-state capture-recapture data of invasive carp in the Illinois River

Background Hidden Markov Models (HMMs) are often used to model multi-state capture-recapture data in ecology. However, a variety of HMM modeling approaches and software exist, including both maximum likelihood and Bayesian methods. The diversity of these methods obscures the underlying HMM and can exaggerate minor differences in parameterization. Methods In this paper, we describe a general framework for modelling multi-state capture-recapture data via HMMs using both maximum likelihood and Bayesian methods. We then apply an HMM to invasive silver carp telemetry data from the Illinois River and compare the results estimated by both methods. Results Our analysis demonstrates disadvantages of relying on a single approach and highlights insights obtained from implementing both methods together. While both methods often struggled to converge, our results show biologically informative priors for Bayesian methods and initial values for maximum likelihood methods can guide convergence toward realistic solutions. Incorporating prior knowledge of the system can successfully constrain estimation to biologically realistic movement and detection probabilities when dealing with sparse data. Conclusions Biologically unrealistic estimates may be a sign of poor model convergence. In contrast, consistent convergence behavior across approaches can increase the credibility of a model. Estimates of movement probabilities can strongly influence the predicted population dynamics of a system. Therefore, thoroughly assessing results from HMMs is important when evaluating potential management strategies, particularly for invasive species.

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USGS2024

River control points for algal productivity revealed by transport analysis

Measurement of planktonic chlorophyll- a —a proxy for algal biomass—in rivers may represent local production or algae transported from upstream, confounding understanding of algal bloom development in flowing waters. We modeled 3 years of chlorophyll- a transport through a 394-km portion of the Illinois River and found that although algal biomass is longitudinally widespread, most net production occurs at river control points in the upper reaches (up to 3.7 Mg chlorophyll- a y −1 km −1 ). Up to 69% of the algal biomass in the upper river was a result of within-reach production, with the remainder recruited from headwaters and tributaries. High chlorophyll- a measured farther downstream was largely because of transport from source-area control points, with substantial net losses of algal biomass occurring in the lower river. Modeling the often-overlooked river transport component is necessary to characterize where, when, and why planktonic algae grow and predict how far and fast they move downstream.

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USGS2023

Predation of invasive silver carp by native largemouth bass is size-selective in the Illinois River

Silver carp ( Hypophthalmichthys molitrix ) are a nonnative, planktivorous, and highly invasive species of cyprinid located throughout the Mississippi River Basin. Although they co-occur with largemouth bass ( Micropterus nigricans ), an abundant native predatory fish, their predator–prey relationship is poorly understood. This potential relationship warrants investigation as largemouth bass are large-gaped predators capable of exhibiting top-down control on planktivorous fishes. The objectives of this study were to determine if largemouth bass consume juvenile silver carp, and if there was a relationship between length of largemouth bass and length of silver carp consumed. Largemouth bass were collected from the La Grange Pool of the Illinois River using 60 Hz-pulsed DC electrofishing and their diets were analyzed (n = 389, total length = 70–578 mm). Evidence of silver carp was present in 18% of diets of largemouth bass that consumed fish. Lengths of consumed silver carp were estimated from the dimensions of their recovered chewing pads or pharyngeal teeth in the stomachs of largemouth bass. A significant relationship between length of largemouth bass and length of silver carp consumed ( p < 0.001, F = 34.63, r 2 = 0.61) was observed. Estimated total lengths of silver carp were 34–101 mm and were recovered from diets of largemouth bass that were 94–262 mm total length. These results indicate enhancement of native largemouth bass populations is unlikely to substantially reduce silver carp populations in the Illinois River or in other waterways where these species co-occur.

Illinois↗
USGS2023

Incorporating metapopulation dynamics to inform invasive species management: Evaluating bighead and silver carp control strategies in the Illinois River

1. Invasive species management can benefit from predictive models that incorporate spatially explicit demographics and dispersal to guide resource allocation decisions. 2. We used invasive bigheaded carps ( Hypophthalmichthys spp.) in the Illinois River, USA as a case study to create a spatially explicit model to evaluate the allocation of future management efforts. Specifically, we compared additional harvest (e.g. near the invasion front vs. source populations) and enhanced movement deterrents to meet the management goal of reducing abundance at the invasion front. 3. We found additional harvest in lower river pools (i.e. targeting source populations) more effectively limited population sizes upriver at the invasion front compared to allocating the same harvest levels near the invasion front. Likewise, decreasing passage (i.e. lock and dam structures) at the farthest, feasible downriver location limited invasion front population size more than placing movement deterrents farther upriver. 4. Synthesis and applications. Our work highlights the benefits of adopting a multipronged approach for invasive species management, combining suppression of source populations with disrupting movement between source and sink populations thereby producing compounding benefits for control. Our results also demonstrate the importance of considering metapopulation dynamics for invasive species control programs when achieving long-term management goals.

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USGS2022

Changes in aquatic vegetation cover following lock closure on the Illinois Waterway from 2019 – 2021

Over the summer of 2020, the Illinois Waterway was closed to complete maintenance on lock chambers along the Illinois River. This closure restricted inter-pool vessel traffic along the river and potentially changed habitat characteristics for aquatic vegetation establishment and growth. To assess if patterns of vegetation establishment and growth changed during the closure, peak biomass imagery from 2019 (pre closure) and 2021 (post closure) were compared for a vegetation response. This assessment found locations where aquatic vegetation increased and locations where aquatic vegetation decreased. However, due to unforeseen limitations in vegetation and water sampling, a causal reason for observed changed in vegetation could not be established.

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USGS2018

Using reverse-time egg transport analysis for predicting Asian Carp spawning grounds in the Illinois River

Identifying spawning grounds of Asian carp is important for determining the reproductive front of invasive populations. Ichthyoplankton monitoring along the Illinois Waterway (IWW) has provided information on abundances of Asian carp eggs in the IWW's navigation pools. Post-fertilization times derived from egg development stages and water temperatures can be used to estimate spawning times of Asian carp eggs, but estimating how far these eggs have drifted requires information on river hydraulics. A Fluvial Egg Drift Simulator (FluEgg) program was designed to predict the drift of Asian carp eggs in the riverine environment with egg growth considered. This paper presents a reverse-time particle tracking (RTPT) algorithm for back-casting the spawning location of eggs from their collection site. The RTPT algorithm was implemented as a module in FluEgg. The new version of FluEgg was coupled with an unsteady hydrodynamic model of the IWW to predict the spawning locations for 530 eggs that were collected in June 2015. The results indicate that tailwater sections below the Locks and Dams (L&Ds) in each navigation pool appear to be preferred spawning locations for Silver Carp. From the data analyzed, the most upstream spawning location for the June 2015 spawning period was in the upper Marseilles navigation pool, downstream of the Dresden Island L&D. The RTPT algorithm can efficiently estimate spawning locations for multiple egg samples.

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USGS2018

Field evaluation of carbon dioxide as a fish deterrent at a water management structure along the Illinois River

Construction of a water management structure (WMS) in the levee surrounding The Nature Conservancy’s Emiquon Preserve (Havana, Illinois, USA) created a new hydrological connection and potential aquatic invasive species pathway between the Illinois River and a large conservation wetland complex. Site managers need a control tool that deters the upstream passage of non-native fishes into the wetland lakes, but does not interfere with normal gate operation and water discharge. This short field study evaluated carbon dioxide (CO 2 ) injected into water as a non-obstructive method to reduce fish abundance near the WMS culverts. We quantified relative fish abundance using underwater sonar with and without injection of CO 2 into culverts during three discharge events: no flow (0 m 3 /s), restricted flow (0.9 m 3 /s), and unrestricted flow (3.2 m 3 /s). Overall, CO 2 reached or exceeded our target concentration of 100 mg/L during no flow and restricted flow, and fish abundance was 70–95% lower at culvert entrances relative to untreated control days. The target CO 2 level was not reached during unrestricted flow and fish abundance was not reduced during CO 2 injection. Atmospheric CO 2 concentrations were inconsequential and unaffected by CO 2 treatments throughout testing. Results from this initial field study provide several considerations for CO 2 as a fish deterrent in natural environments.

Illinois↗
USGS2017

Water guns affect abundance and behavior of bigheaded carp and native fish differently

Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm 3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis , Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus ). Water guns were deployed in a channel that connects the Illinois River to backwater quarry pits that contained a large transient population of bigheaded carp. To evaluate the effect of water guns, mobile side-looking split-beam hydroacoustic surveys were conducted before, during and between replicated water gun firing periods. Water guns did not affect abundance of bigheaded carp, but abundance of native fish detected during the firing treatment was 43 and 34% lower than the control and water guns off treatments, respectively. The proximity of bigheaded carp to the water gun array was similar between the water guns on and water guns off treatments. In contrast, the closest detected native fish were detected farther from the water guns during the water guns on treatment (mean ± SE, 32.38 ± 3.32 m) than during the water guns off treatment (15.04 ± 1.59 m). The water gun array had a greater impact on native fish species than on bigheaded carp. Caution should be taken to the extrapolation of these results to other fish species and to fish exposed to water guns in different environments (e.g., reduced shoreline interaction) or exposure to a larger array of water guns, or for use of water guns for purposes other than a barrier.

Illinois↗
USGS2017

Using pharyngeal teeth and chewing pads to estimate juvenile Silver Carp total length in the La Grange Reach, Illinois River

The Silver Carp Hypophthalmichthys molitrix is an invasive species in the Mississippi River basin; an understanding of their vulnerability to predation as juveniles may inform control by native predators and predator enhancement (e.g., stocking). Digestion of Silver Carp prey recovered from diets makes it difficult to determine the size‐classes that are most vulnerable to predation by native fishes. The objective of this study was to determine whether the sizes of the chewing pad (CP), pharyngeal teeth (PT), and pharyngeal arch (PA)—the Silver Carp structures most often found intact in predator diets—were predictive of the TL of prey Silver Carp. During 2014 and 2015, juvenile Silver Carp ( n = 136; <180 mm) were collected using 60‐Hz pulsed‐DC electrofishing and mini‐fyke nets in the La Grange reach of the Illinois River. We extracted Silver Carp CPs ( n = 136 fish) and PAs with PT intact ( n = 129 fish) and measured CP length (CP L ) and width (CP W ), eight reproducible PT landmarks (PT1 L –PT4 L ; PT1 W –PT4 W ), and four reproducible PA landmarks (PA1–PA4) to the nearest 0.01 µm. Using simple linear regression, we found a strong predictive relationship between measurements of CP, PT, or PA and the TL of Silver Carp. The CP L ( r 2 = 0.94) and CP W ( r 2 = 0.94) had the strongest relationships with Silver Carp TL, followed by PA1 ( r 2 = 0.89) and PT1 L ( r 2 = 0.87). These strong relationships suggest that all three structures could be used in diet analyses to accurately estimate Silver Carp TL and thus further our understanding of predator–prey dynamics for this high‐risk invasive species.

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