Pre-registration and additional fees are required for participation. If you signed up online, you will receive a ticket in your registration materials.
Fee: Student - $10; Professional $40 (lunch on own)
Contact: Tricia Fry, Fish and Wildlife Health Coordinator, Midwest Association of Fish and Wildlife Agencies, tfry.mafwa@gmail.com Co-Organizers: Deb Hudman, MDC; Ellen Hayes, SEAFWA/SCWDS; Tricia Fry, MAFWA Workshop sponsored by the North Central Section of The Wildlife Society.
Overview: Understanding and monitoring wildlife diseases helps wildlife managers make informed decisions about conservation strategies, population control, and habitat management. Training and adherence to established protocols can significantly enhance the outcomes of wildlife disease management efforts. This workshop will provide a comprehensive overview of the following key aspects of a wildlife disease event: disease discovery, incident evaluation, biosafety, sample collection and submission for diagnostic testing, and incident management. The workshop will incorporate case studies of fish and wildlife disease outbreaks to provide real-world context and enhance learning by illustrating key concepts and practices. The workshop will conclude by examining how adopting a One Health integrative strategy enhances the effectiveness of monitoring, surveillance, and management of wildlife diseases, benefiting public health and biodiversity.
Intended Audience: Students and Professionals interested in wildlife heath
AUTHORS: Chris Newbold, Missouri Department of Conservation
ABSTRACT: The Missouri Department of Conservation conducted a 700 + acre prairie reconstruction project at Prairie Fork Conservation Area in east-central Missouri from 2004-2019. This long-term reconstruction project provided an opportunity to use a chronosequence approach to assess the success of two reconstruction methods in emulating local, reference remnant prairie plant communities. We compared broadcast dormant seeding following two types of site preparation, agricultural cropping (Crop) or herbicide control in existing grass assemblages (Grass), and remnant communities. The Crop site preparation method resulted in a rapid increase in richness shortly following seeding. Although more similar to remnant assemblages initially, the Grass method took longer for mean coefficient of conservatism and floristic quality index to approach conditions of the reference communities. However, neither method resulted in plant community compositions that converged with the reference through time. Further, indicator species analysis identified a diverse assemblage of species lacking from the reconstructed prairies. This information is important for land managers in the development of adaptive management strategies during active reconstruction. We also provide some ‘lessons learned’ over the course of the 15-year reconstruction project that could be useful to other prairie managers.
ABSTRACT: Shaw Nature Reserve has been tinkering with landscape-scale woodland management for biodiversity since the 1980s, using local manager-based institutional knowledge as well as site-specific scientific studies to back up their methods. We present insights and findings from management of woodlands and savannas, with a focus on the combination of 1) invasive species control, 2) prescribed fire, and 3) native herbaceous species re-introductions using locally-sourced seed.
AUTHORS: Elizabeth Yohe, U.S. Forest Service - Eastern Region; Kyle Steele, U.S. Forest Service - Mark Twain National Forest; Mike Leahy, Missouri Department of Conservation; Brian Davidson, U.S. Forest Service - Mark Twain National Forest; Rebecca Landewe, U.S. Forest Service - Mark Twain National Forest; Jason Stevens, U.S. Forest Service - Eastern Region; Greg Nowacki, U.S. Forest Service - Eastern Region
ABSTRACT: The Missouri Pine-Oak Woodlands Restoration Project (MOPWR) on the Mark Twain National Forest (MTNF) is one of 17 currently funded projects across the country supported by the U.S. Forest Service Collaborative Forest Landscape Restoration Project (CFLRP). The project aims to restore mixed shortleaf pine (Pinus echinata)-oak (Quercus spp.) woodlands that have historically dominated this landscape. Alongside other methods, the Community Health Index (CHI) assessment was utilized to monitor restoration progress and results in this landscape. Our monitoring data suggests that we are moving selected restoration units toward more ecological functionality. However, uncertainty remains as to whether or not reference conditions are attainable, given modern-day concerns and obstacles.
AUTHORS: Carolyn A. Stephen, Missouri Department of Natural Resources; Jamie H. Ladner, National Park Service; Dan G. Drees, National Park Service; Lauren L. Sullivan, Michigan State University
ABSTRACT: This abstract was previously published in the journal Fire Ecology. Citation: Stephen, C.A., Drees, D.G., Ladner, J.H., Sullivan, L.L. Fire effects on plant communities in Ozark woodlands and glades. Fire Ecology 20, 70 (2024). https://doi.org/10.1186/s42408-024-00299-3 Background: Decades of fire suppression caused drastic changes to community structure and composition across ecosystems, including in Ozark woodlands in Missouri, United States. Reintroducing fire can restore ground flora by reducing midstory tree density, increasing ground layer light, and reducing leaf litter accumulation, but we lack a clear understanding of how these effects vary across time and space. We investigated the effects of repeated prescribed fire on ground flora species richness, floristic quality, abundance, community composition, and stand structure over 20 years in a landscape matrix of dry-mesic woodlands, dry woodlands, and glades using data collected from the Ozark National Scenic Riverways Fire Effects Monitoring program in the Current River Watershed in the Missouri Ozarks. Results: We found that fire plays a key role in driving community structure and dynamics across community types, although with varying levels of intensity. Herbaceous species richness, abundance, and floristic quality index increased across all community types, while mean coefficient of conservatism decreased. Abundance and floristic quality effects were stronger in drier sites. Community composition changed with successive burns, resulting in several indicator species for post burn treatments. The density of midstory trees declined across community types with repeated fire. The number of burns significantly affected overstory tree density overall, but overstory tree density only declined in dry woodlands and glades and not in dry-mesic woodlands. Conclusions: Our results suggest that landscape fire shapes plant community structure and dynamics. Specifically, these findings show that fire effects vary among community types and suggest that land managers should consider landscape heterogeneity in fire application for restoration. Separate community types imbedded in the same landscape may respond to fire differently. Understanding repeated fire effects over several decades across multiple community types is critical to informing fire-driven woodland restoration across landscape scales.
ABSTRACT: Following decades of focused fire suppression efforts in the early to mid-20th century, prescribed fire as a landscape management tool faced heated controversy as the concept and its application in Missouri landscapes developed in the 1980’s. By the 1990’s, prescribed fire became a common and accepted practice to maintain fire-adapted natural communities to the benefit of their associated flora and fauna. Missouri State Parks took a leading role in applying prescribed fire to a variety of natural communities statewide and now maintains over 42,000 acres within a burn rotation with nearly 10,000 acres burned annually throughout Missouri State Park lands. Contemporarily, prescribed fire in is again under a microscope as some within the greater conservation community have shared concerns regarding potential negative impacts from prescribed fire to natural communities. Primary questions include burn seasonality, application methods and where fire is applied. This brief discussion will explore steps Missouri State Parks staff are taking and challenges they are encountering to best replicate historic fire processes for the benefit of flora and wildlife in Missouri State Park landscapes. Additionally, preliminary findings from recent research and monitoring efforts to address potential negative fire impacts will be shared.
AUTHORS: Ken McCarty, Missouri State Parks (retired)
ABSTRACT: Native Ozark woodland- and glade dominated landscapes easily support 30 to 40 percent of Missouri’s native plant species at even a single site, including large numbers of conservative species. Their plant-dense, season-long floral progressions potentially support equally robust and diverse bee communities. Forty years of conservation effort protecting remnants, applying fire, and managing woody density or composition has yielded impressive examples and many designated Missouri Natural Areas. Intensive surveys since 2016 have explored bee diversity and bee community characteristics across 17 such sites within Missouri’s state parks. This presentation summarizes the findings, to emphasize the important role remnant native ecosystems play as reservoirs of bee biodiversity, and benchmarks that may help pollinator conservation efforts in more developed or altered contemporary environments.
AUTHORS: Frank Nelson, Missouri Department of Conservation
ABSTRACT: The wetlands in southeastern Missouri have a long history of alteration. Since the 1950’s, Duck Creek Conservation Area has been managed by the Missouri Department of Conservation to provide wetland habitat for waterfowl and other wetland dependent species within this altered landscape. Over time our philosophy of wetland management, the implications of infrastructure design, and the interaction of natural features has evolved. Based on a hydrogeomorphic assessment of the larger Mingo basin surrounding Duck Creek we identified the four following objectives to renovate the aging wetland management area: 1) restore natural water flow patterns where possible, 2) mimic natural water regimes, 3) restore natural vegetation communities, and 4) accommodate public uses that are consistent with resource objectives. A multi-disciplined team of biologists and engineers used a basin wide digital elevation model, aerial photos, and field observations to examine the landscape features and identify opportunities to restore wetland system processes to achieve these objectives. These steps have reduced several chronic management challenges, increased the wetland habitat diversity, and enhanced the wetland function of the area. Following construction, we've been able to document the responses of both aquatic and avian communities through the annual cycle and periods of flood connectivity. The collaborative approach and incorporation of system processes into the renovation have benefited Duck Creek Conservation Area.
AUTHORS: Caitlin Bloomer, University of Illinois Urbana-Champaign; Joel Corush, Illinois Natural History Survey; Mark Davis, Illinois Natural History Survey; Maxwell Hartman, Arkansas Game and Fish Commission
ABSTRACT: The Slenderwrist Burrowing Crayfish, Fallicambarus petilicarpus, is a short-range endemic restricted to the Ouachita River drainage in south-central Arkansas and northern Louisiana. U.S. Fish and Wildlife Service is currently evaluating this species for listing as threatened or endangered under the Endangered Species Act (ESA). Since 2021, teams of inter-agency biologists have been collecting data on this species to inform the listing decision. We used species distribution modeling to identify habitat associations and estimate the total available habitat within the known range of this species. We used Restriction-site associated DNA sequencing (RADseq) to establish effective population size and estimate genetic differentiation between populations. Here we will present an overview of our data collection and how our results support the listing of this species under the ESA. We will also highlight the major data gaps that still exist and how we plan to address them through future field studies.
AUTHORS: Patrick F. Allison Jr., University of Mississippi; Corey G. Dunn, U.S. Geological Survey, North Carolina Cooperative Fish & Wildlife Research Unit; North Carolina State University; Susan B. Adams, USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research; Jesse W. Breinholt, LGC RAPiD Genomics; Kenneth A. Sterling, USDA Forest Service; Devin M. Raburn, North Carolina Cooperative Fish & Wildlife Research Unit; North Carolina State University; Zanethia C. Barnett, USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research; Ryan C. Garrick, University of Mississippi
ABSTRACT: Recent advancements in morphological data collection and molecular phylogenetics have resulted in numerous updates to crayfish taxonomy. However, there are still problematic taxa among these decapods. The genus Hobbseus is one such group, as the morphological characters traditionally used for species identification can provide ambiguous diagnoses. Given that some Hobbseus species have been petitioned for listing under the Endangered Species Act, this uncertainty is particularly concerning, as it inhibits implementation of effective conservation strategies. We reassess the taxonomy of Hobbseus using an integrative approach to species delimitation that combines morphological and molecular data. We include four complementary datasets: 1) traditional morphometrics; 2) geometric morphometrics; 3) single-locus mitochondrial DNA sequences; and 4) multi-locus hybrid enrichment single copy nuclear DNA sequences. Here, we provide preliminary results from analyses of the DNA sequence datasets.
AUTHORS: ZAchary J. Loughman, West Liberty University; Parker Hildreth, Tennessee Wildlife Resource Agency; Jonathan D. Eisenhour, Office of Kentucky Nature Preserves; Eric Ng, West Liberty University, Kaleb Norris, West Liberty University; Kathryn Schulz, West Liberty University; Michael C. Compton, Office of Kentucky Nature Preserve.
ABSTRACT: Cambarus jezerinaci, the Spiny Scale Crayfish, is a small headwater species endemic to the central Appalachians of Kentucky, Tennessee, and Virginia. Recently C. jezerinaci was petitioned for federal listing, resulting in the need for a Species Status Assessment (SSA). With the exception of C. jezerinaci description, limited surveys have been completed for this taxa. Cambarus jezerinaci has an interesting distribution in Kentucky, with populations known to occur prior to survey efforts in the South Fork of the Kentucky River basin, as well as the Upper Cumberland watershed. In the summer of 2022, a weeklong survey effort procured new C. jezerinaci locations in the Middle Fork of the Kentucky River, as well as the Upper Cumberland. Genetic samples were taken on all animals captured and analyzed with 2 COI genes. Results of this work indicated that multiple lineages existed for C. jezerinaci in Kentucky that differ genetically from type populations, warranting more dedicated work. In the summer of 2024, in accordance with the Kentucky Crayfish Blitz as well as the WLU Crayfish Laboratory, 306 sites were sampled across the entirety of the Kentucky Fork basins, as well as the Upper Cumberland watersheds. Cambarus cf. jezerianci was procured from 28.2% of sites sampled. Genetic samples were acquired from all specimens and will be analyzed using RADSeq methods. Future work will focus on elucidating the conservation genetics and taxonomic standing of C. jezerinaci to support the completion of the SSA.
AUTHORS: Dusty Swedberg, Prairie Research Institute - Illinois Natural History Survey; Archis Grubh, Texas Parks and Wildlife Department; Christopher Taylor, Prairie Research Institute - Illinois Natural History Survey
ABSTRACT: Crayfishes are a diverse and ecologically important component in Texas's aquatic ecosystems. Timely information on distribution, abundance, habitat needs, and threats is needed to effectively manage this resource. Texas currently has ten crayfish species of greatest conservation need, five of which were the focus of our sampling: Procambarus brazoriensis, Procambarus nigrocinctus, Procambarus nechesae, Procambarus nueces, and Procambarus texanus. From 2022 to 2024, we sampled almost 100 sites targeting these species and have been able to collect each of the five species. Our collections and the associated habitat data have documented possible range reduction in Procambarus nueces and Procambarus texanus. While also documenting Procambarus nigrocinctus and Procambarus nechesae might be more common than initially perceived. Procambarus brazoriensis is documented as a highly seasonal crayfish with collections that only occur in early spring. With our collection data, we are able to draw conclusions on range and habitat data to better estimate the conservation status for these five crayfishes and other sympatric species that were collected through our efforts.
AUTHORS: Hannah Holbert, West Liberty University; Zackary Graham, West Liberty University; Zachary Loughman, West Liberty University
ABSTRACT: There is no standard for individual captive husbandry of Cambaridae crayfish species, despite captive propagation being an important factor in reintroduction efforts. The Big Sandy Crayfish (Cambarus callainus) and the Guyandotte River Crayfish (Cambarus veteranus) are recognized under the Endangered Species Act as Threatened and Endangered, respectively. Active propagation projects are underway for C. callainus, but standards are still being developed. In order to set a baseline protocol for these federally listed Cambarus species, a shelter preference study was conducted using the Big Water Crayfish (Cambarus robustus). C. robustus is a large-bodied, tertiary burrowing crayfish species native to the eastern coast of the United States and Ontario, Canada. C. robustus commonly occurs in lotic environments and prefers large slab boulders for shelter. Due to similar life history strategies and habitat preferences, this species serves as a potential surrogate for related species such as C. callainus. 31 individual crayfish took part in two trials each, where shelter choices included a natural rock shelter and a piece of clear acrylic, or a natural shelter and tinted acrylic. Trials were conducted for 24-hours, where shelter usage and behavior were monitored through video recordings. Our results suggest that C. robustus will use all shelter types, although natural shelters were occupied more frequently overall. Sex and size of the individuals had minimal or no influence on shelter use. Future research should continue to investigate optimal husbandry practices and rearing techniques for Cambarus species where propagation efforts are necessary.
AUTHORS: Calvin R. Rezac, Mississippi Museum of Natural Science, Mississippi Department of Wildlife, Fisheries, and Parks
ABSTRACT: In 2020, a genetic and morphological evaluation of the Rusty Gravedigger (Lacunicambarus miltus) by Glon et al. supported the elevation of two new species, the Banded Mudbug (L. freudensteini) and the Lonesome Gravedigger (L. mobilensis). Based on the published study by Glon et al., both species occur only in Mississippi and Alabama and were thought to be confined between the Pascagoula and Mobile Rivers. The reported range of both species is currently less than 1,000 km2 and are among the most-narrow ranged species within the state of Mississippi. With only 5 known localities for each species in the state, further efforts to determine the status and complete distribution were needed. Herein, we report on the results from a burrowing crayfish survey at novel sites within and outside the known range of both focal species in Southeastern Mississippi. Surveys took place between January-August 2024, and at each site we collected crayfish using hand excavation, slurp guns, and dip nets. Additional notes on habitat, burrow abundance, and soil composition were also recorded. In total, 104 sites (22 via boat) were surveyed and 21 species were captured including both target species. Banded Mudbug was capture at 11 sites within the known range of the species; however, we failed to expand the species into notable areas outside its range. Lonesome Gravedigger was found at 16 sites, but was notably found in areas more north and west than previously reported. The results of the survey help to improve the understanding of Mississippi burrowing crayfish distribution and status in the state. Notes on other newsworthy crayfish research at the Mississippi Museum of Natural Science may also be discussed.
AUTHORS: Montana Fonner, West Liberty University; Zachary Loughman, West Liberty University
ABSTRACT: Cambarus veteranus (Guyandotte River Crayfish) has been in severe population decline since their description in 1914 by Faxon. In 2016 the species was listed as endangered under the Endangered Species Act due to a widespread range reduction. The major contributing factor to this decline is siltation caused by both historic and current logging and mining operations. C. veteranus occupies the interstitial spaces between slab boulders and the benthos. Siltation fills the interstitial space both, smothering live crayfish and reducing habitat availability by cementing slab boulders into the stream bed. C. veteranus is endemic to the Upper Guyandotte River Basin. Historically C. veteranus was found in 8 tributaries of the mainstem of the Upper Guyandotte River. Today C. veteranus is only found in one historic tributary, Pinnacle Creek. More recently, another stream, Clear Fork/Laurel Fork, was found to harbor populations of C. veteranus. Despite the conservation standing of C. veteranus a comprehensive habitat study on the mainstem of the Upper Guyandotte River has not been conducted. This study aims to investigate the mainstem of the Upper Guyandotte River and Lower Pinnacle Creek to determine habitat quality. We recorded observations of anthropogenic degradation, such as siltation, bank instability, and pollution. Data collected will be used towards mitigation efforts in restoring habitat suitability within the study area for C. veteranus. In addition, habitat data collected along the mainstem was integrated in crayfish collection surveys, at possibly overlooked locales, which were determined to have potentially suitable habitats for C. veteranus.
AUTHORS: Cameron Haeffner, Southern Illinois University; Dr. Greg Whitledge, Southern Illinois University
ABSTRACT: Naturally occurring chemical markers in calcified structures, such as otoliths and fin rays or spines, have been commonly used in the study of fish environmental history, including identifying natal environments of wild fish, distinguishing stocked from wild fish, and inferring sources of invasive species. There are a few examples of the use of natural chemical markers in aquatic invertebrates, but this technique has not been used for crayfishes. Eye stalks have been used to estimate age of some crustaceans and may contain a microchemical record of crayfish environmental history, although this has not been tested. The objectives of this study are to determine whether crayfish eye stalks reflect microchemical (Sr:Ca, Ba:Ca) signatures of water, whether water-eye stalk microchemistry relationships differ among species, and whether this structure retains microchemical signals of previously occupied environments following crayfish transfer or molting. Four species of crayfish (Faxonius virilis, F. illinoiensis, F. luteus, and F. punctimanus) were collected from several streams in Missouri and Illinois with different water microchemical signatures. A laboratory study was also conducted in which crayfish were transferred between waters with different Sr:Ca ratios to assess signature retention. Eye stalks were sectioned and analyzed using laser ablation-ICPMS. If eye stalks contain a microchemical record of crayfish environmental history as anticipated, this technique could potentially be used to reconstruct environmental history (e.g., origin, movement) of crayfishes in the wild and may also be useful for inferring sources of non-native species.
AUTHORS: Anna Raney, University of Missouri and Florida Fish and Wildlife Conservation Commission; Jacob Westhoff, U.S. Geological Survey, Missouri Cooperative Fish and Wildlife Research Unit, School of Natural Resources
ABSTRACT: Crayfish invasions are among the top global threats to native crayfish populations. In Missouri, cross-basin introductions have impacted multiple endemic species. The Saint Francis River crayfish (Faxonius quadruncus) and Big Creek crayfish (F. peruncus), endemic to the upper Saint Francis River (USFR) drainage in Missouri, are currently under threat of extinction due to introductions of Woodland Crayfish (F. hylas) from nearby drainages. Previous research has documented reduced abundances and range reductions for both native species in reaches invaded by Woodland Crayfish. However, the entire ranges of the native species have not been systematically sampled prior to this study, and past survey data documenting the invasion are over 15 years old. Management agencies need updated information to create an informed recovery plan for the two threatened species. Using a stratified random sampling design, we conducted a basin-wide distribution survey at 96 sites across the USFR drainage in 2022-2023. We incorporated presence-absence data from this survey with coarse-scale environmental variables into random forest, boosted regression, and spatial stream network models to create species distribution models for the two endemic species and the invasive Woodland Crayfish population. Additionally, we used targeted, intensive sampling to locate the leading edges of invasion in six streams. During these efforts, we discovered and mapped additional invasions in two major tributaries to the USFR drainage and documented a 1.4 km range expansion upstream from the 2009 leading edge in Orr Hollow Creek. The Woodland Crayfish is now present in most major tributaries on the left side of the basin as well as multiple locations in the mainstem river. Despite these range expansions, small impoundments at multiple locations appeared to harbor refuge populations of endemic crayfish based on survey data. Results from this study can be used to identify refugia for native species and locate barriers to further invasion.
AUTHORS: Eric R. Larson, University of Illinois; Caitlin C. Bloomer, University of Illinois; Don Eaton, Minnesota Department of Natural Resources; Denver Link, University of Minnesota; Reagan Oller, University of Illinois; Gretchen J.A. Hansen, University of Minnesota
ABSTRACT: The signal crayfish (Pacifastacus leniusculus), native to the Pacific Northwest of North America, is among the most invasive crayfish species globally, with populations widely established throughout Europe and Japan. Signal crayfish have never been detected from eastern North America, although previous research has identified the Upper Mississippi and Great Lakes watersheds as environmentally suitable for this invasive species. In October of 2023, ten signal crayfish individuals were trapped from a lake in west central Minnesota by a commercial bait harvester. We report here molecular surveillance of this possible, incipient signal crayfish invasion. Mitochondrial DNA (mtDNA) barcoding identified the collected crayfish as P. leniusculus, resembling non-native populations of the species known from the Lake Tahoe area of California and Nevada. We collected environmental DNA samples in summer and autumn of 2024, including through sampling kits distributed to lake association volunteers, and used quantitative PCR with a signal crayfish-species primer and probe assay to survey for evidence of this species in the original lake and neighboring freshwater ecosystems. Our preliminary results are relevant to management responses for this novel, potentially impactful invasive species in the Midwest.
AUTHORS: Caden J. Jungbluth, Wisconsin Cooperative Fishery Research Unit, Molecular Conservation Genetics Lab; Amy L. Springer, Wisconsin Cooperative Fishery Research Unit, Molecular Conservation Genetics Lab; Stephen F. Spear, U.S. Geological Survey, Upper Midwest Environmental Sciences Center; Jared J. Homola, U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit
ABSTRACT: Prevention of new invasive species often hinges on early detection and quick removal. Aquatic invasive species can be especially difficult to detect without extensive sampling due to habitat complexity and low initial abundances. Point-of-use biomolecule detection methods provide a possible solution via near real-time identification of DNA or other biological materials. Loop-mediated isothermal amplification (LAMP) provides a user-friendly approach for environmental (e)DNA detection that can be easily deployed in the field and yield diagnostic results within 40 minutes. Water can be filtered and the eDNA can be rapidly extracted with a Chelex resin and a portable heat block. We are developing a LAMP assay for red swamp crayfish (Procambarus clarkii) to enable identification of introductory pathways (e.g. the pet trade) and monitoring of the spread of established invasion sites. We generated 36 candidate primer sets that we evaluated in silico for red swamp crayfish specificity using the program BLAST to identify DNA sequence alignments to other species in the NCBI database. Sixteen species-specific candidate primer sets were then optimized for temperature of the LAMP reaction and brand of master mix. The optimal set of conditions were then used to further evaluate species-specificity through test amplifications of extracted DNA of related species (i.e. other Procambarus crayfish). Finally, we performed limit of detection testing down to a concentration of 1 copy/μL of target DNA, with consistent detections present at 100 copies/μL. Field collection of eDNA water samples from known infested waterbodies is underway to identify potential environmental inhibitors to our ability to detect red swamp crayfish presence. This tool could be implemented to detect—and possibly prevent—invasions through rapid field-based monitoring in areas where red swamp crayfish are a concern for introduction and spread.
AUTHORS: William Ota, Michigan State University; Aaron Sullivan, Michigan State University; Sarah Walker, Michigan State University; Brian Roth, Michigan State University
ABSTRACT: Red swamp crayfish (Procambarus clarkii) are the planet's most widely distributed invasive crayfish. They are a keystone species that can alter shoreline stability, macroinvertebrate communities, trophic interactions, water quality, and macrophytes in invaded ecosystems. This species became established in Michigan in 2017 within ponds and lakes, initiating an adaptive management plan to monitor, mitigate, and/or eradicate invasive populations. From 2021-2023, we tracked red swamp crayfish using radio telemetry in seven ponds in Southeast Michigan. Crayfish from 32 - 42 mm were tagged and tracked weekly for 5-6 months per individual over 2 years. A total of 235 crayfish were tagged and successfully tracked. Red swamp crayfish home range size was significantly affected by pond size (p
AUTHORS: Sarah Walker, Michigan State University; Brian Roth, Michigan State University; William Ota, Michigan State University; Colin Assenmacher, Michigan State University; Aaron Sullivan, Michigan State University
ABSTRACT: Red swamp crayfish (Procambarus clarkii) are global invaders that negatively affect ecosystems worldwide through bank erosion, trophic interactions, and competition. There is limited research about their habitat preferences in invaded areas inside North America or in lentic ecosystems. Our study evaluates habitat selectivity by red swamp crayfish in southeastern Michigan ponds where red swamp crayfish were first found in 2017. We used radio telemetry to track the movement and habitat characteristics of confirmed locations for 46 crayfish at 4 sites in June through September of 2022. We used remotely sensed habitat characteristics from 2022 NAIP aerial imagery and determined macrophyte cover, terrestrial vegetation cover, and shore use of each detection. We then analyzed these classifications for selectivity using Ivlev’s Electivity Index. We gave further context to these classifications and selectivity by analyzing them with our field habitat observations in a logistic regression. Our index indicated a strong avoidance of shore areas, an avoidance of no cover areas, and a non-selective use of macrophyte areas. We also demonstrated slightly more selectivity for areas with terrestrial cover in male I crayfish and less avoidance of terrestrial vegetation cover areas in ponds with less macrophytes. Field observed deep water habitat characteristics significantly (p-value
AUTHORS: Colin Assenmacher, Michigan State University; William Ota, Michigan State University; Kathleen Quebedeaux, Michigan Department of Natural Resources, Fisheries Division; Brian Roth, Michigan State University
ABSTRACT: Procambarus clarkii are the world’s most widespread invasive crayfish species established in Michigan since 2017. P.clarkii is of high concern due to their extensive burrowing behavior, which can damage human infrastructure through bank erosion and decreased bank stability. Our research aimed to investigate how soil and environmental characteristics of pond banks relate to P.clarkii burrow density. We measured key soil characteristics and potentially influential environmental variables from July to August of 2024 at 74 sites invaded by P.clarkii in Southeast Michigan to quantify which physical properties influence variations in burrow density within a waterbody and across multiple waterbodies. These sites were spread across 13 invaded waterbodies at three golf courses with varying burrow densities. Calculated burrow density was based on surveys conducted during the 2023 and 2024 field seasons and ranged from 0 to 8.42 burrows per square meter across sample sites and targeted waterbodies. We collected soil cores at each site to determine particle size, percent organic matter, penetration resistance, bulk density, and profile soil horizons. Bank slope, percent vegetation cover, and canopy cover were measured at each coring location. Preliminary analysis indicates regions of low burrow density are associated with steeper pond banks, particularly in the first 50 cm from the waterline. Mean vegetation cover ranged from 80 to 84% across burrow density classes and 35 to 99% over all sites. Penetration resistance was highest in areas of no burrow activity. We found less variation in soil bulk density and percent canopy cover in areas with high burrow density. This indicates that P.clarkii has preferred soil and environmental characteristics when burrowing. These findings help to identify the physical characteristics of high burrowing areas, which will be used to assist in the development of preventative management strategies against P.clarkii establishment and burrowing.
AUTHORS: Dalton Clayton, Department of Natural Resource Ecology and Management, Iowa State University;
Dr. Michael Moore, USGS Iowa Cooperative Fish and Wildlife Research Unit;
Dr. Michael Weber, Department of Natural Resource Ecology and Management, Iowa State University;
ABSTRACT: The introduction of aquatic invasive species can have negative ecological impacts on invaded ecosystems. Rusty Crayfish (Faxoninus rusticus), a species native to the Ohio River Basin, has extended its range into 28 US states, 3 Canadian provinces, and Western Europe. Rusty Crayfish can displace native crayfishes through competition, destabilize aquatic food webs, alter habitat through bioturbation and consumption of aquatic vegetation, and predate on fish eggs, presenting management challenges. Managers currently lack information on Rusty Crayfish distribution and habitat selection in shallow lakes and wetlands in the glaciated, agriculturally dominated landscapes found near the southern and western margins of their introduced range. Thus, our objective is to determine the habitat associations of Rusty Crayfish in Storm Lake, IA, to help understand Rusty Crayfish habitat selection in a novel habitat on their invasion front and its relationship to native crayfish habitat selection. To explore our objective, we deployed 708 baited minnow traps to sample crayfishes from June through August of 2023 and 2024, across three depths bins (~0-1.5m, 2-3m, 3+m). We also collected habitat data, including dissolved oxygen, pH, water temperature, dominant substrate, and presence of cobble and macrophytes at each trap location. We captured 85 invasive Rusty Crayfish and 47 native Virile Crayfish (Faxonius virlis). Rusty crayfish capture probability increased with cobble substrate, macrophytes, and earlier in the summer. Virile Crayfish capture probability was positively associated with macrophytes, they were more likely to be captured later in the summer and were more likely to captured in the medium and deep depth bins. Our results suggest that Rusty Crayfish and Virile Crayfish are not overlapping in habitat usage, which may suggest competition or niche partitioning.
AUTHORS: John F. Bieber, Loyola University Chicago; Ivàn Beck, Colorado College; Reuben Keller, Loyola University Chicago
ABSTRACT: The Chicago River represents a system that is at the edge of several invasion fronts; two of which are the invasive crayfish P.clarkii and F. rusticus. For years, these populations have remained in distinct areas of the Chicago River with little overlap, however; the factor(s) that limits their spread is not known. This project used complimentary field and lab experiments to investigate how stress levels (measured via hemolymph glucose) differed among the populations along a gradient in the Chicago River to inform where populations are in the river.
For the field study, we trapped crayfish in the Chicago River and immediately drew hemolymph from captured individuals. We hypothesized that stress would be the greatest for P.clarkii near Lake Michigan, where populations have not yet been found, and simultaneously would be the lowest for F.rusticus as they are established in Lake Michigan.
In the lab study, we collected P.clarkii along with water from the area where they were captured for holding in lab. Crayfish acclimated in lab before the tanks were filled with Lake Michigan water, and hemolymph was collected after a 90 min period. We hypothesized that P.clarkii populations near Lake Michigan would show lower relative stress to immersion in lake water compared to individuals further downstream and compared to individuals that were not flushed with lake water.
Interestingly, we found that individuals further downstream exhibited elevated glucose compared to individuals closer to Lake Michigan, and our lab studies showed that immersion in Lake Michigan water reduces stress compared to individuals without immersion. Collectively, our results suggest environmental contaminants may be driving the distribution of crayfish. Additionally, this work highlights the importance of considering physiology when managing an invading species.
AUTHORS: Cheyenne E. Stratton, Missouri Department of Conservation; Donald C. Behringer, University of Florida; Jamie Bojko, Teesside University; Margaret L. Taylor, University of Florida; Lindsey S. Reisinger, University of Florida
ABSTRACT: Parasites can affect their hosts’ ecological impacts by reducing host density and altering host traits such as behavioral traits. Most research focuses on density-mediated impacts, but trait-mediated impacts may be equally or more important as they control the interactions among organisms. Parasites can act as top-down forces in ecosystems and can trigger trophic cascades through density- or trait-mediated effects. We investigated how a parasite alters the well-documented ecological impacts of the invasive rusty crayfish (Faxonius rusticus). In 2019, we discovered a significant decline in the F. rusticus population in a Wisconsin lake corresponding to an outbreak of a microsporidian parasite, Nosema rusticus, which reduced infected crayfish activity levels. We hypothesized that infected crayfish, due to reduced activity and lethargy, would have lesser impacts on lower trophic levels including macrophytes and leaf litter (i.e., a trait-mediated trophic cascade). We also predicted that N. rusticus would increase crayfish mortality. To test this, we conducted a 4-week mesocosm experiment in which we varied parasite prevalence to test the trait-mediated indirect effects of the microsporidium on resource biomass and abundance. We also varied crayfish density to compare the strength of trait-mediated effects to a reduction in crayfish density. In support of our hypothesis, we found that less macrophytes and leaf litter were consumed in mesocosms with infected crayfish. Our results also suggest that this parasite is likely to cause density-mediated effects because crayfish infected with N. rusticus had higher mortality rates. These results suggest that parasites can mitigate the impacts of invasive species through both trait- and density-mediated trophic cascades.
