AUTHORS: Max Monfort, University of Wisconsin La Crosse US Geological Survey Upper Midwest Environmental Science Center; James Wamboldt, US Geological Survey Upper Midwest Environmental Science Center; Matthew Acre, US Geological Survey Columbia Environmental Research Center; Andrew Mueller, US Geological Survey Columbia Environmental Research Center; Dustin Broaddus, US Geological Survey Columbia Environmental Research Center; Jacob Griffin, US Geological Survey Columbia Environmental Research Center; David Schumann, University of Wisconsin La Crosse
ABSTRACT: Grass Carp (Ctenopharyngodon idella) consumption of aquatic macrophytes can alter trophic dynamics when introduced to new aquatic ecosystems. Increased commercial captures and expansion into further reaches of the Upper Mississippi River (UMR) could have negative affects to these aquatic ecosystems. Efforts to control this highly mobile and illusive species in the UMR and Great Lakes Basins are a substantial challenge to managers. A potential bait for Grass Carp has been evaluated at other invasion fronts (e.g., Lake Erie), but its application in the UMR has not yet been fully recognized. We refined methods and utilized 2023 longitudinal movement data to describe the utility of automated bait delivery systems to aggregate Grass Carp in pool 19 of the UMR in 2024. Specifically, our objectives were to: (1) describe Grass Carp movement ecology within the riverscape before, during, and after bait application, and (2) determine Grass Carp movement responses to baiting; use of the baiting area, time occupied at baiting area, and the effective attraction distance from the baiting area. Grass Carp (n = 90) behavior was evaluated in response to the deployment of a novel Grass Carp specific bait via automated bait delivery systems in four distinct habitats using acoustic telemetry arrays from March-November 2024. If successful, these methods could provide an exploratory, yet innovative, Grass Carp management strategy for more efficient removals within the UMR and other invasion fronts.
AUTHORS: Kroboth, P. T., M. E. Colvin, C. L. Broaddus U.S. Geological Survey, Columbia Environmental Research Center, Columbia, MO 65201
ABSTRACT: Black Carp Mylopharongodon piceus were imported into the United States in the 1980s for use in aquaculture. Since then, escapes have occurred and reported wild captures have increased. Black Carp are a concern because of potential impacts on native ecosystems and direct predation on native imperiled mollusks. Based on commercial captures, hoop nets set in mainstem riverine habitats of the Mississippi River during spring and summer are a potential capture method. We assessed commercial fisheries Black Carp catches by kernel density analysis to identify an area of increased catch. Within this area we assessed the seasonality and rate of commercial captures, and tested targeted hoop net effort for Black Carp during 2021 and 2022. We compared Black Carp catch and co-occurring species using non-metric multi-dimensional scaling. We fit Black Carp catch and environmental covariates by general linear models: Poisson, negative binomial, zero-inflated Poisson, zero-inflated negative binomial, hurdle Poisson, and hurdle negative binomial, with the top fitted models selected based on ΔAIC < 2. The model set was refitted for predictions and inference on the model confidence set. Hoop net captures were 63% of commercial records (n=759). The confluence of the Missouri and Mississippi rivers had the greatest density of commercial captures with 39% of hoop net captures in this area, primarily during July-September. Captures were characterized by median water temperature 26.7°C, median river stage 5.02 m, and median day of year 231 (DOY; mid-August). Ordination identified similarity in covariates of Smallmouth Buffalo Ictiobus bubalus and Black Carp catch. Most captures occurred in select outside-bend or secondary-channel habitats. The probability of capturing ≥ 1 Black Carp increased with depth, DOY through September, and declined with increasing current velocity. Results indicated catch was maximized in summer and early fall when stage and current velocity are lower allowing net sets in deeper areas.
AUTHORS: Jesse R. Fischer, US Geological Survey; Josey L. Ridgway US Geological Survey
ABSTRACT: Several technologies were recently developed by the U.S. Geological Survey (USGS) to provide managers and researchers with cost-effective solutions to assess, deter, and capture invasive Silver Carp (Hypophthalmichthys molitrix) populations. These tools and techniques were designed to exploit the unique physiological and behavioral characteristics of Silver Carp. Specifically, Silver Carp exhibit strong schooling, jumping, and net-avoidance behaviors that have often created challenges for traditional methods of capture. Research on Silver Carp from a variety of habitats and population densities throughout the Mississippi River Basin has demonstrated a widespread need to create new methods to capture, deter, or control these invasive populations. Nets were developed to target low-to-intermediate densities of invasive carp by eliciting jumping while limiting bycatch. Surface-floating gill nets provide a cost-effective tool for assessing and monitoring invasive carp populations (e.g., population assessment, capturing individuals for telemetry studies). For high density populations, a corral net was designed and tested for concentrating large biomasses of fish with an emphasis on preventing escape and maintaining survival until removal. Both novel nets were designed to be used in conjunction with substrate-to-surface block-nets that can control and direct movements of individuals. Additional tools to be used with these nets include deployable underwater speakers with remote operation capabilities. These mobile acoustic deterrents were created and assessed for modifying invasive carp behavior, such as, stimulating jumping or directing movement towards areas for increased capture. Semi-autonomous watercraft were also designed and extensively field-tested to assist with invasive carp assessment and monitoring using consumer-grade sonar to estimate abundance and biomass and control strategies using remotely operated stimuli (e.g., acoustic, bubbles, lights) to concentrate fish or to elicit jumping for capture objectives. Future work will continue to demonstrate and transfer new technologies to non-USGS partners to accomplish research and management objectives across subbasins within the Mississippi River.
AUTHORS: P. Ryan Jackson, U.S. Geological Survey; Vindhyawasini Prasad, University of Illinois at Urbana-Champaign; Henry F. Doyle, University of Illinois at Urbana-Champaign; Amy E. George, U.S. Geological Survey; Cory D. Suski, University of Illinois at Urbana-Champaign; Benjamin H. Stahlschmidt, U.S. Geological Survey; Jesse R. Fischer, U.S. Geological Survey; Duane C. Chapman, U.S. Geological Survey; Anne M. Herndon, U.S. Geological Survey; Curt G. Byrd, U.S. Geological Survey; Rafael O. Tinoco, University of Illinois at Urbana-Champaign
ABSTRACT: Management of invasive carp populations in North America has long relied on harvest of adult fish. However, to effectively suppress population growth, it may be necessary to harvest invasive carp at multiple life stages, including ichthyoplankton (eggs and larvae). Despite substantial advances in understanding invasive carp reproduction requirements over the past decade, management agencies currently lack the necessary tools to control early life stage invasive carp and reduce recruitment and dispersal. An interdisciplinary team of biologists, hydrologists, and engineers has spent the past three years developing and testing a method for passive capture of invasive carp eggs and larvae drifting downstream in an open channel without disruption to navigation or conveyance. Inspired by microplastic collection systems deployed in Europe, this novel method uses a bubble screen to induce secondary flows in the channel, which redirect invasive carp eggs and larvae to passive collection gears. This presentation will summarize the results of this study to date, discuss new methods for experimentation with preserved eggs and surrogates, discuss the challenges of passive capture of ichthyoplankton in open-river conditions, and present our ongoing research and vision for the future of this emerging technology. Furthermore, insights gained from this study can inform the design of physics-based egg and larval traps, both with and without bubble screens, for monitoring and early detection. The potential for application to passive ichthyoplankton monitoring with improved probability of detection will also be discussed.
AUTHORS: Janice L. Albers, Jessica C. Stanton, Andrea K. Fritts, U.S. Geological Survey Upper Midwest Environmental Sciences Center; Nicholas Swyers, Matthew D. Sholtis, U.S. Geological Survey Western Fisheries Research Center, Columbia River Research Laboratory; Jon Vallazza, Dan Gibson-Reinemer, U.S. Geological Survey Upper Midwest Environmental Sciences Center; Theodore R. Castro-Santos, U.S. Geological Survey Eastern Ecological Science Center; Christa M. Woodley, U.S. Army Engineer Research and Development Center; Marybeth K. Brey, U.S. Geological Survey Upper Midwest Environmental Sciences Center
ABSTRACT: Invasive bigheaded carps, with their unique hearing specialization, exhibit behavioral responses to underwater acoustic signals. This intriguing behavior has prompted further research into whether these signals could be used to deter invasive carps from moving into sensitive areas or further upstream. Preventing or slowing movements of invasive carps around movement bottlenecks, such as navigation locks and dams, can minimize propagule pressure in upstream locations and provide additional time and opportunity for removal or other management actions while also minimizing impact on native species. Testing of underwater acoustic signals at large, management-relevant scales is a necessary step in determining the feasibility of this tool for long-term management of invasive carps. We evaluated an underwater acoustic deterrent system (uADS) installed in the downstream approach of the navigation lock at Lock and Dam 19 on the Mississippi River near Keokuk, Iowa. We analyzed the movement behaviors of invasive carp (bighead, silver, and grass carp) and various native species, implanted with acoustic transmitters, in relation to the uADS operation status and environmental covariates. Using multiple analytical approaches, we assessed the impact of the uADS on upstream lock passage; the rate that fish enter and exit various zones in the lock approach; and movement behavior around the deterrent. Results from this study will inform managers about the effectiveness of a uADS at preventing upstream lock passage by invasives relative to native fish species, movement behavior of fish as they interact with the deterrent and lock structure, and logistics and maintenance of uADS installations.
AUTHORS: Liam Odell, Kansas Department of Wildlife and Parks; Chris Steffen, Kansas Department of Wildlife and Parks
ABSTRACT: Introduced invasive carp have become established throughout the Missouri River basin. The feeding habits, population densities, and interactions with river users cause significant ecological damage as well as lower the desires to use bodies of water with established invasive carp populations. The Kansas River is a major tributary of the Missouri River and is one of three publicly accessible and navigable waterways in the state of Kansas. Upstream from the Kansas River are several large reservoirs that are highly utilized for outdoor recreation such as fishing, boating, nature watching, etc. The Bowersock Dam serves as a critical control point for the management of invasive carp in the Kansas River system. Only six bighead carp have been documented upstream of this structure. These six bigheads were previously assumed to have passed over the Bowersock Dam during an extreme flood event in 1993 (120,000 cfs). A recently completed study has raised concerns that invasive carp can pass over the Bowersock Dam at much lower flows (25,000 cfs). Kansas Department of Wildlife and Parks will integrate a physical deterrent at the Bowersock Dam to prevent invasive carp from moving over the dam and making their way upstream into reservoirs and the rest of the Kansas River.
AUTHORS: Brett Anderson, Nebraska Cooperative Fish and Wildlife Research Unit, University of Nebraska-Lincoln; Jonathan J. Spurgeon, U.S. Geological Survey, Nebraska Cooperative Fish and Wildlife Research Unit, University of Nebraska-Lincoln.
ABSTRACT: Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis (hereafter bigheaded carp) have invaded tributaries to the Missouri River and Platte River in Nebraska. Herding is a method used to increase the capture efficiency and detection probability of adult bigheaded carp by using active and passive sampling gears simultaneously. Nevertheless, more information is needed about how herding can be applied to mid-order rivers and how it compares to more conventional methods such as electrofishing. During June-July 2023, four herding techniques were assessed regarding their ability to elicit directional movement past an enclosure gate. Herding using an underwater speaker and pulsed-DC electrofishing proved effective at directing bigheaded carp into a capture area. From June-August 2024, herding was conducted on three tributaries to the Missouri River and one tributary to the Platte River to assess the effectiveness of gill-net sets at removing fish from a capture area. Herding and standard electrofishing were assessed based on catch rates, labor hours, and crew sizes. The results of this study will provide managers, researchers, and stakeholders knowledge regarding efficient and cost-effective sampling strategies for invasive bigheaded carp that enable assessments of presence and population status as well as provides control options for population reduction and potential removal.
AUTHORS: Josey L. Ridgway, U.S. Geological Survey; Jesse R. Fischer, U.S. Geological Survey; Jessica M. Howell, U.S. Fish and Wildlife Service; John Schulte, Missouri Department of Conservation; Adam C. Jones, U.S. Geological Survey; Jason M. Goeckler, U.S. Fish and Wildlife Service; Robin D. Calfee, U.S. Geological Survey.
ABSTRACT: Invasive Silver Carp (Hypophthalmichthys molitrix) populations can reach extremely high densities and severely affect biodiversity and ecosystem function. There are currently few sampling or monitoring techniques available to natural resource managers that reliably quantify population responses to management actions. Consumer-grade sonar offers a cost-effective approach for mapping distributions and evaluating density before and after intensive control efforts. Recent advancements in consumer-grade technologies have vastly improved resolution and dependability sufficient for fisheries research and management. We developed cost efficient semiautonomous watercraft for surveying fish and aquatic habitats by combining low-cost, consumer-grade technology (i.e., sit-on-top kayaks, electric trolling motors, side-scan sonar). Semiautonomous watercraft are advantageous for surveys of invasive Silver Carp populations because of GPS-guidance capabilities with consistent tracking and speed, quiet propulsion system to minimize fish disturbance, and the potential to deploy multiple survey vessels for increased survey efficiency, while minimizing the effect of fish movements. We used two semiautonomous watercrafts to conduct repeated surveys on a population of Silver Carp in Creve Coeur Lake, St. Louis, Missouri, USA (130-ha oxbow lake of the Missouri River). Surveys were conducted at night (≥1h after sunset) and were 2-h in duration. We used an image-analysis software to automate fish target detection and size estimation to estimate density and biomass. Fish targets in side-scan sonar imagery were apportioned by size using fish community capture data collected using electrified trawl that was conducted approximately one week after seasonal surveys. Bathymetry data were used to convert counts to fish density (number)/volume (m3) and biomass (kg)/volume (m3). Preliminary estimates suggest Silver Carp biomass was over 228,600kg. Repeated surveys will be used to assess variability among estimates and to determine which season is optimal (e.g., limiting fish-boat avoidance) for standardizing future Silver Carp surveys. Final population estimates will assist in establishing harvest objectives for Creve Coeur Lake.
AUTHORS: Kellie Hanser, U.S. Fish and Wildlife Service; Jessica Howell, jessica_howell@fws.gov; Jason Goeckler, jason_goeckler@fws.gov
ABSTRACT: Silver Carp (Hypophthalmichthys molitrix) relative abundance and demographic information is essential to guide management and control measures. Interconnection across river basins has allowed Silver Carp to establish a reproducing population along the entirety of the free-flowing portion of the Missouri River and its tributaries. Population information is being collected with an electrified dozer trawl to establish baseline invasive carp data in tributary confluences to monitor populations and guide management efforts as they begin to increase. Because Silver Carp are located throughout the Missouri River, tributaries are sampled along a large spatial gradient (river miles 170 – 800) to help track and delineate populations trends across the basin. From 2020 – 2023, a total of 611 transects have been completed collecting over 29,000 individuals from 50 different species. However, most fish sampled are invasive carp with the total number of individuals exceeding 15,000. Data shows that Silver Carp across tributaries are demographically similar, with large older individuals in the higher latitude tributaries. Age data indicates the 2019-year class is still currently dominant across the basin. Annually, the relative abundance, size structure, body conditions, sex ratio, age structure, recruitment, growth, and mortality are analyzed and provided through the Missouri River Basin Invasive Carp Partnership in a collaborative effort to help inform the Silver Carp status for the basin.
AUTHORS: Tammy M. Wilson, U.S. Geological Survey - Columbia Environmental Research Center Michael E Byrne, Department of Natural Resources, University of Missouri, Columbia Thomas W. Bonnot, Department of Natural Resources, University of Missouri, Columbia Robin D Calfee, U.S. Geological Survey - Columbia Environmental Research Center Matthew R Acre U.S. Geological Survey - Columbia Environmental Research Center
ABSTRACT: Grass carp (Ctenopharyngodon idella) are nonnative, herbivorous freshwater fish that represent an invasive, ecological threat in North American waters. They originate from eastern Asia, consume large amounts of aquatic vegetation, and establishment in novel waters can cause significant ecosystem changes. There is particular concern for grass carp establishment within the Lake Erie basin, where multi-jurisdictional grass carp removal efforts have been ongoing since 2017 to reduce Lake Erie's population and the chance of dispersal to the rest of the Great Lakes. However, effectiveness of removal efforts has yet to be quantified. Grass carp in Lake Erie are data-limited as catch numbers are < 100 per year. Therefore, we used multiple length-based stock assessment methods to evaluate if removal efforts were sufficient to reduce population size. We used a combination of length-based indicators (LBI), the length-based spawning potential ratio (LBSPR), and the length-based Bayesian biomass estimation (LBB) method to assess the stock. Although these length-based methods run on the assumption of a stock at equilibrium rather than a potentially growing population, by using multiple length-based methods to assess this stock, we worked to minimize biases that may have occurred. Preliminary results highlight the absence of immature removals and indicate that removal efforts may need to target smaller fish to collapse the population.
AUTHORS: Dillon Weik, University of Toledo; Christine Mayer, University of Toledo; Tammy Wilson, US Geological Survey; Ryan Young, US Fish & Wildlife; Eric Weimer, Ohio Department of Natural Resources; John Dettmers, Great Lake Fishery Commission
ABSTRACT: Invasive grass carp have been captured in Lake Erie since the mid-1980s, and spawning in tributaries to the lake was confirmed in 2015. In response, a multi-jurisdictional partnership was established to target grass carp for removal with increasing effort since 2017. However, capture data is limited, making supplemental biological data, such as growth histories estimated from bony structures, especially useful in describing trends in the population or individual traits. Age was estimated using vertebrae for all fish removed from Lake Erie since 2012, and growth was back-calculated using the Biological Intercept Model. The back-calculated growth was then fitted to a Von Bertalanffy Growth Function. Lake Erie grass carp age-at-maturity (as indexed by a decrease in growth rate) of diploid fish was estimated to be ~3 years. In contrast, literature derived age-at-maturity ranges from 1-10 years. Current removal methods select fish > 880 mm (age-4). Consequently, recruitment may occur before fish are vulnerable to removal. Therefore, future efforts are needed to target smaller fish by exploring alternative habitats or examining new sampling gears to remove these cryptic individuals before they are able to successfully recruit to the population.
