AUTHORS: Stephen M. Tyszko, Ohio Department of Natural Resources, Division of Wildlife; Jeremy J. Pritt, Ohio Department of Natural Resources, Division of Wildlife; Richard D. Zweifel, Ohio Department of Natural Resources, Division of Wildlife; Stuart A. Ludsin, The Ohio State University; Joseph D. Conroy, Ohio Department of Natural Resources, Division of Wildlife; Jay Kelly, The Ohio State University; Michael Figueroa, Ohio Department of Natural Resources, Division of Wildlife.
ABSTRACT: Stocking yearling Channel Catfish to mitigate perceived predation by Largemouth Bass has long been the convention despite greater costs compared to stocking smaller life stages. We quantified recruitment of stocked cohorts of Channel Catfish and investigated the effects of stocking life stage (fingerling vs. yearling), Largemouth Bass density (low vs. high), and their interaction on the percentage of a cohort recruiting to the adult population and fishery. Marked (magnetized wire tags) cohorts of advanced fingerling and yearling Channel Catfish were concurrently stocked into reservoirs with low (7 reservoirs, CPUE < 100 fish/h) and high-Largemouth Bass density (5 reservoirs, CPUE > 100 fish/h) populations. We sampled these reservoir Channel Catfish populations with baited, tandem hoop nets 7–8 years after stocking and estimated recruitment. We used a linear mixed model with reservoir as a random effect to test whether cohort recruitment differed by life stage stocked, Largemouth Bass density, or their interaction. Overall, the mean percentage of Channel Catfish recruiting to the adult population and fishery in cohorts stocked as advanced fingerlings was 2.4% (SE = 0.69%) and the mean percentage in cohorts stocked as yearlings was 10.6% (SE = 2.8%). Largemouth Bass density did not have a significant effect on recruitment (P = 0.43) while the effects of stocking life stage (P < 0.001) and the interaction between Largemouth Bass density and stocking life stage (P < 0.003) were significant. The highest recruitment occurred in cohorts stocked as yearlings in reservoirs with high densities of Largemouth Bass. Stocking advanced fingerling Channel Catfish can produce viable year classes in reservoirs with low or high densities of Largemouth Bass. In addition to higher cost, stocking yearling Channel Catfish may result in excessive densities and slow growth.
AUTHORS: Danielle Shubat, Eastern Illinois University; Daniel Roth, Eastern Illinois University; Robert Colombo, Eastern Illinois University; Eden Effert-Fanta, Eastern Illinois University
ABSTRACT: Channel Catfish (Ictalurus punctatus) are a popular and sought after sportfish to anglers across the United States, having substantial value for both recreational and commercial fisheries. However, their populations in impoundments often rely on stockings of fingerlings. In Illinois, the lack of standardized sampling protocols for catfish has made it difficult to adequately evaluate stocking efforts and assess population dynamics. This study aimed to determine the most effective sampling methods for Channel Catfish in impoundments, assess demographic variation among impoundments, and test the efficacy of artificial spawning structures to increase natural reproduction and recruitment in three Illinois reservoirs (Lake Charleston, Lake Mattoon, and Lake Paradise). After two years of seasonal sampling using multiple gears, we found that baited tandem hoop-nets in the fall yielded the best catch rates and we will continue to use this sampling method. Our population assessments and microchemistry analyses of pectoral spines show that Channel Catfish in these lakes are primarily stocked fish, suggesting low natural reproduction. However, the relationship between stocking rates and the observed differences in population density and demographics remains unclear. We hypothesized that the lack of recruitment may be due to insufficient spawning habitat and sought to increase availability of this habitat by adding nest boxes in the study lakes. Preliminary trials showed that Channel Catfish used these structures, and future goals include expanding nest box installations and monitoring for natural recruitment over time. Adding nest boxes to create suitable habitat for these catfish to reproduce may facilitate annual recruitment thereby reducing cost and effort of hatchery operations. If successful, this approach could be implemented in other lakes and ponds to naturally sustain catfish populations.
AUTHORS: Ryan Eastman, Wisconsin Cooperative Fishery Research Unit; Jason Breeggemann, Wisconsin Department of Natural Resources; Robert Davis, University of Wisconsin - Madison Center for Limnology; Daniel Dembkowski, Wisconsin Cooperative Fishery Research Unit; Daniel Isermann, U.S. Geological Survey
ABSTRACT: Green Bay and its tributaries support a world-class fishery for trophy muskellunge that attracts anglers from across North America, but there has been little evidence of natural recruitment and the population remains reliant on stocking to sustain the fishery. Previous efforts to document natural recruitment have focused on the Fox and Menominee rivers where spawning is known to occur. Results of these assessments suggest that hatching success in these rivers is limited. However, recent telemetry-based research indicates that approximately half of Green Bay muskellunge spawn in non-tributary locations. These locations could represent important yet unconsidered sources of natural recruitment in southern Green Bay. Furthermore, anecdotal observations suggest spawning occurs in the Sturgeon Bay area but it is unknown if these fish contribute to the broader southern Green Bay population. Our objectives for this project are to determine if: (1) successful hatching is occurring at open-water locations in Green Bay, including locations in the Sturgeon Bay area, (2) presence of eggs or larval muskellunge at a location is related to a suite of habitat characteristics including distance to shore, bottom slope, depth, dissolved oxygen, substrate type, and aquatic vegetation, and (3) muskellunge spawning in the Sturgeon Bay area contribute to the overall population in southern Green Bay. We are integrating intensive egg and larval fish sampling and acoustic telemetry to address our objectives. We will present preliminary results related to spawning and hatching in non-tributary locations based on sampling efforts during the 2024 field season. We will also discuss the framework of our acoustic telemetry approach to assess the contribution of muskellunge spawning in the Sturgeon Bay area to the broader Green Bay population.
AUTHORS: Kaden Ball, South Dakota State University; Chuck Mordhorst, Arizona Game and Fish Department
ABSTRACT: This study examined the population dynamics of a severely stunted Yellow Perch Perca flavescens population in a high mountain reservoir in the White Mountains of Arizona. River Reservoir sustains a low-density population of trophy Brown Trout Salmo trutta creating a highly prized regional fishery. Yellow Perch have been determined to be an important prey item for Brown Trout in this system contributing to the large sizes Brown Trout attain in the reservoir. The yellow perch population has always been assumed to be stunted based on field observations, but this had never been confirmed. In order to determine if stunting was occurring and to what extent we aged Yellow Perch using otoliths and quantified rates of growth recruitment and mortality. We determined that Yellow Perch in this system are severely stunted relative to other populations and discuss the implications for managing a highly utilized trophy Brown Trout fishery based on these results.
AUTHORS: David D. Duvernell, Missouri S&T; Veronica M. Lee, Missouri S&T; Eric J. Ludwig, Missouri S&T; Aaron D. Geheber, University of Central Missouri; Brett Landwer, Missouri Department of Conservation; Leah K. Berkman, Missouri Department of Conservation
ABSTRACT: Biodiversity monitoring in freshwater habitats provides essential data for assessing and quantifying spatiotemporal patterns and long-term changes. Fisheries biologists use a variety of capture-based methods for biodiversity sampling. Non-capture-based methods have come into common use that rely on the detection of environmental DNA (eDNA), which is released by organisms into their environment. Metabarcoding involves the filtering and extraction of eDNA from samples, followed by sequencing and alignment to a reference database to infer species presence. We worked closely with the Missouri Department of Conservation (MDC) to perform comparative biodiversity assessments using traditional capture-based methods along side eDNA metabarcoding methods. In support of our efforts, we submitted 189 new reference sequences to GenBank, to bring statewide databased coverage of Missouri fish species to over 90%. We teamed with the Resource Assessment and Monitoring (RAM) program to sample sites in six drainages of the Missouri Ozarks, and we worked with Cape Girardeau fisheries biologists to sample lowland habitats in Black Island Conservation Area along the Mississippi River. In Ozark streams we were able to detect approximately double the number of species compared to standard RAM sampling methods, while in the aquatic habitats at Black Island we increased the number of documented species by more than a third relative to MDC survey records dating back to 1940. eDNA sampling missed or failed to discriminate among very few species detected by RAM sampling or documented at Black Island. These missed species were either rare (often single specimens) or were pairs or trios of closely related species with highly similar sequences that were indiscernible using eDNA sequencing methods. Spatial analyses demonstrated that eDNA sampling was sensitive to changes in fish assemblages along Ozark stream habitat gradients, and habitat complexity at Black Island.
AUTHORS: Lewis J. Bruce, Iowa Department of Natural Resources; John Lorenzen, Iowa Department of Natural Resources
ABSTRACT: Creel surveys (i.e., counting and interviewing anglers) are one of the sampling tools used to gauge the amount and type of fishing activity on a pond, lake, or river. Creel surveys provide important information about user demographics, preferences towards fish species and sizes of fish, fish harvest, trip length, and trip expenditures. Collecting these data gives managers insight into what their constituents want. A traditional creel survey consists of two components: 1) random counts of anglers to assess the level of use; and 2) angler interviews to determine more about the typical fishing trip (e.g., how long, what they are catching) and other information about the angler. Randomly counting anglers requires a creel clerk to be on site regularly and, therefore, limits the number of concurrent creel surveys that can be conducted using this traditional method. Another issue with traditional creel surveys is the fact that the mere presence of what some of the public perceive to be a law enforcement figure can result in anglers altering their behavior (e.g., leaving the lake). Time lapsed photography (TLP) was used to collect diurnal count data from multiple lakes simultaneously and these data were collected in an unbiased manner. Cameras were used seasonally (i.e., open water and ice fishing) at some locations and year-round at others. During a 4 year period 20 urban ponds were surveyed using TLP. Hide box maintenance, camera reliability, vandalism, and data processing efforts were also monitored and quantified during this project.
AUTHORS: Keith Hurley, Nebraska Game and Parks Commission
ABSTRACT: FinCatchDE is a mobile-friendly, data entry application that was developed as part of the FinCatch ecosystem - Nebraska Game and Parks Commission’s new database and analysis system for lentic fish sampling data. Utilizing a University of Nebraska – Lincoln capstone computer science project provided a low-cost alternative in obtaining a team of developers to generate this component. Additionally, along the way both technological and data-driven innovations were implemented to improve fish community sampling in the state. We will discuss the process and ideas used for FinCatchDE during this presentation in the hopes that others who are upgrading and transitioning their sampling databases can benefit from our lessons learned.
AUTHORS: Steven J. Herrington, The Nature Conservancy, MN-ND-SD; Tyler Winter, Native Fish For Tomorrow; Solomon R. David, The University of Minnesota Matthew L. Miller, The Nature Conservancy, Science Communications
ABSTRACT: North America has the highest diversity of freshwater fishes of any temperate region worldwide. These species face numerous threats to their long-term conservation. Fisheries management is amongst the tools that governments, Tribes, and other interested parties can use to ensure this biodiversity sustainably persists and thrives into the future. “Rough fish” is a pejorative term often used by resource managers and anglers to group a large number of native fishes – including gars and numerous sucker species – that are perceived to have little fisheries or cultural value, and thus are often poorly managed and exploited. In 2024, the State of Minnesota passed the first law in the U.S. affording fisheries management protections for 26 native fishes now recognized by the state as “native rough fish”. This action sets a precedent for recognizing the inherent, cultural, and fisheries importance of these species that can be replicated or adapted by other states nationwide. This presentation will provide an historical perspective of “rough fish” regulations, recommendations for their future conservation management, and applicability to states in the Midwest.
AUTHORS: Samantha A. Embersits, Wisconsin Cooperative Fishery Research Unit; Daniel A. Isermann, U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit; Daniel J. Dembkowski, Wisconsin Cooperative Fishery Research Unit; Margaret H. Stadig, Wisconsin Department of Natural Resources
ABSTRACT: The Lake Winnebago System (LWS) population in east-central Wisconsin represents one of the largest self-sustaining populations of lake sturgeon Acipenscer fulvescens in North America that supports an annual spearing fishery each February. Lake sturgeon spawn at more than 70 locations within tributaries to the LWS, but the extent and timing of spawning that occurs at many sites remains unknown. Understanding lake sturgeon use of spawning locations is important in allocating sampling effort needed to mark fish and obtain population estimates used in setting safe harvest levels for the fishery. Furthermore, some spawning sites represent habitat improvement efforts implemented by the Wisconsin Department of Natural Resources and little to no evaluation has been performed at these sites to determine relative use and potential for successful hatching. Our objectives were to describe lake sturgeon use, measure egg deposition rates and survival, and verify whether hatching is occurring at selected spawning locations in the Wolf River drainage, including sites where habitat improvements have occurred. Spawning sites were or will be visited repeatedly during the 2024 and 2025 spawning seasons and lake sturgeon are visually counted along defined transects. Eggs are collected with a manual transfer pump and D-frame drift nets are used to collect larvae. We will present results from our first sampling season. The information from our research may help the Wisconsin Department of Natural Resources strategically allocate spring sampling effort so that more sites can be sampled and could provide guidance regarding future habitat improvement projects.
AUTHORS: Juliana Kaloczi, Iowa State University; Michael J Moore, U.S Geological Survey, Iowa Cooperative Fish and Wildlife Research Unit and Iowa State University; Martin Hamel, University of Georgia; Gene Jones, Iowa Department of Natural Resources; Ryan Hupfeld, Iowa Department of Natural Resources, Rebecca Krogman, Iowa Department of Natural Resources.
ABSTRACT: Globally, sturgeon populations have declined due to overharvest for caviar and habitat fragmentation due to dam construction that impairs water quality and disrupts spawning migrations. North American species have had harvest restrictions enacted to recover populations. While similar life history characteristics make Shovelnose Sturgeon vulnerable to many of these same stressors, populations in the Mississippi River basin still support limited commercial and recreational fisheries for roe and meat - conferring the species’ economic, recreational, and cultural importance. Enacting harvest regulations, such as minimum length limits, ensures sustainable harvest and requires knowledge of dynamic rates such as age-specific growth rates. However, the Shovelnose Sturgeon’s long life span and slow growth make estimating these parameters notoriously difficult with traditional methods that rely on annuli counts on bony structures. As a result, there is a lack of reliable growth rates for this species across its range. Therefore, we used an 18-year mark-recapture dataset for Shovelnose Sturgeon collected by the Iowa Department of Natural Resources in the Cedar River at Palisades-Kepler State Park to evaluate incremental growth models for Shovelnose Sturgeon. The Fabens modification of the Von Bertalanffy growth function was used within a Bayesian framework to determine how growth rates vary within the population. Additionally, bomb-radiocarbon age estimates were used to inform a second model within the Bayesian framework to assess how the incorporation of previous knowledge may improve the model. Age estimates and growth rates can be used in population simulations to evaluate sensitivity to harvest under harvest regulations and can inform management across the species’ range.
AUTHORS: Andrew Briggs, Michigan Department of Natural Resources; Justin Chiotti, U.S. Fish and Wildlife Service; James Boase, U.S. Fish and Wildlife Service; Jan-Michael Hessenauer, Michigan Department of Natural Resources; Jeannette Kanefsky, Michigan State University; Brad Utrup, Michigan Department of Natural Resources; Todd Wills, Michigan Department of Natural Resources
ABSTRACT: The Michigan Department of Natural Resources (MDNR) and U.S. Fish and Wildlife Service (USFWS) have been conducting Lake Sturgeon surveys in the St. Clair – Detroit River System (SCDRS) since 1996. Over this period determining sex of Lake Sturgeon has been difficult as the primary method to determine sex has been expulsion of gametes, which rarely occurs (particularly for females). Recent advances in genetic methods have shown that sex of Lake Sturgeon can be determined from a tissue sample or fin clip through molecular sexing. MDNR and USFWS have collected pectoral fin rays from Lake Sturgeon for aging purposes since their surveys began and have stored them over the years, allowing for a portion of these fin samples to be clipped and used for molecular sexing. MDNR and USFWS combined to provide over 2,700 tissue samples to Michigan State University for molecular sexing with 53% of the Lake Sturgeon being classified as female. This presentation will examine if sex ratios differed by location within the SCDRS, how sex ratios change by length, and sex-specific growth rates of Lake Sturgeon.
AUTHORS: Brandon Gerig1, School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Avenue, Milwaukee, WI 53204. Email: gerig@uwm.edu
Troy G. Zorn Michigan Department of Natural Resources Fisheries Division, Marquette Fisheries Research Station, 484 Cherry Creek Road, Marquette, MI 49855, USA. Email: zornt@michigan.gov
Kevin Pangle, Central Michigan University, Department of Biology, 1455 Calumet Court, Mount Pleasant, MI 48859, USA. Email: pangl1k@cmich.edu
Nick Peterson, Minnesota Department of Natural Resources, Lake Superior Area Fisheries, 5351 North Shore Drive, Duluth, MN 55804. Email: nick.peterson@state.mn.us
Henry Quinlan U.S. Fish and Wildlife Service, Ashland Fish and Wildlife Conservation Office, 2800 Lake Shore Drive East, Ashland, WI 54806, USA. Email: henry_quinlan@fws.gov
1Presenting author
ABSTRACT: Abstract Identifying streams that host scarce migratory salmonid life histories, such as coaster brook trout, is challenging due to the lack of inexpensive, non-lethal techniques for confirming Great Lake to stream migrations from observations of fish from a single sampling event. We examined prior foraging (and inferred residency) of brook trout using stable isotope analysis of fin clip tissue from 589 fish captured in Lake Superior or tributaries with vs. without access to Lake Superior. We observed strong isotopic separation in δ13C brook trout between Lake Superior and Lake-inaccessible reaches and developed a linear discriminant function (LDF) which assigned fish to these environments with over 97% accuracy. LDF and Bayesian stable isotope mixing models used to estimate stream and lake energy sourcing by brook trout collected from Lake-accessible reaches identified stream of origin and brook trout length as significant covariates influencing energy sourcing. Brook trout caught in Lake-accessible reaches had isotope signatures and sizes that were intermediate to fish from Lake-inaccessible reaches and Lake Superior, potentially indicative of Lake Superior to stream migrations or possibly an energy subsidy from adfluvial migrants in streams. The LDF was used to estimate the probability that recently grown fin tissue from brook trout collected in Lake-accessible reaches resulted from foraging in Lake Superior, with data on fish length and probability of Lake Superior assignment (Pr) used to identify tributaries with “likely” coaster brook trout. However, further research is needed to distinguish between Lake Superior-based foraging and subsidy effects from adfluvial fishes.
