Midwest Fish & Wildlife Conference 2019

AUTHORS: Reuben D. Frey, Eastern Illinois University; Cassi Moody-Carpenter, Eastern Illinois University; Shannon Cassandra Frary Smith, University of Arkansas at Pine Bluff; Robert E. Colombo, Eastern Illinois University

ABSTRACT: Flow regimes have been altered by the construction of dams on many lotic systems in the United States. Physical habitat changes within these systems in response to changed hydrology have been observed to affect the community structures of fish species therein. Removal of dams may revert the physical habitat characteristics of an impounded reach towards that of a free-flowing river system and subsequently invite a fish community shift. I investigated the effects of two separate low-head dam removals on the Vermilion River and North Fork Vermilion River in eastern Illinois on the community structure of Smallmouth Bass (Micropterus dolomieu), Spotted Bass (Micropterus punctulatus), and Largemouth Bass (Mictropterus salmoides). Data were collected from 2012 to 2015 using multiple gear types at six study sites on each river; two sites in the below-dam reach, two sites within the impounded reach, and two sites upstream of the impounded reach. Proportional abundance (pa) of each study species was observed to differ between each reach. Smallmouth Bass in both rivers were observed to have lower proportional abundance within the impounded reaches (pa = 0.005382) and higher proportional abundance in the below-dam (pa = 0.006611) and upstream (pa = 0.007102) reaches. In contrast, Largemouth Bass showed higher proportional abundance in the impounded reaches (pa =0.018838) and lower proportional abundance in the below-dam (pa = 0.010105) and upstream (pa = 0.005356) reaches, with Spotted Bass showing a similar pattern in the Vermilion, but not in the North Fork Vermilion. Variation in proportional abundance of fish may be driven by physical habitat requirements of each species. Future research will investigate the effect of changed flow regime on available physical habitat and Micropterus species community structure following dam removal.

AUTHORS: Bryan Kinter, Mike Wilkerson – Ohio Division of Wildlife

ABSTRACT: Overharvest is a common result of opening small lakes and reservoirs to unregulated public fishing. In lakes comprised primarily of largemouth bass and sunfish (Lepomis spp.), populations dominated by large, older sunfish and abundant largemouth bass quickly become dominated by abundant, small sunfish and few largemouth bass. This can occur after only one year of public fishing and results in a decline in angler use and satisfaction. Maintaining quality fisheries in small lakes requires restrictive harvest regulations of both sunfish and largemouth bass, and frequent evaluation of these regulations is required. Using a combination of trapnet and electrofishing surveys, harvest quotas, length limits, and bag limits, the ODNR-Division of Wildlife successfully maintained quality sunfish/largemouth bass fisheries on the Lake La Su An Wildlife Area from 1983-2011, after these lightly-fished, privately owned lakes were opened to public fishing. Each spring, trapnet and electrofishing surveys were conducted to evaluate bluegill and largemouth bass abundance and size structure. Bluegill harvest quotas were generated based on these estimates while restrictive length limits (minimum or slot) were set for largemouth bass. A complete creel census monitored harvest. From 1987-2011, an average of 40.8% of bluegill over 150mm were also over 200mm, and largemouth bass electrofishing CPE averaged 371 fish/hour. Over 45% of bluegill harvested were greater than 200 mm in total length. The Lake La Su An fishery demonstrates that restrictive harvest regulations can be used to maintain quality fisheries in small lakes open to public fishing. However, extensive agency resources are required to collect the data needed to manage these types of fisheries.

AUTHORS: Zak J. Slagle, Travis Hartman – Ohio Division of Wildlife

ABSTRACT: Ohio anglers have historically fished heavily for black bass, leading to record levels of angler effort and harvest in the late 1990’s. Additionally, missing year classes of bass, invasion of non-native nest predators (Round Goby), and resurgence in possible avian predators (Double-crested Cormorant) were all seen as threats to the bass population through the early 2000’s. Ohio Division of Wildlife also lacked yearly surveys of black basses, complicating fishery management decisions. ODW responded by increasing restrictions on bag limits and minimum sizes for black bass harvest; the 14 inch, 5 fish bag limit that currently stands was created in 2000. A seasonal catch-and-release only regulation was added in 2004 to further reduce harvest after the 2000 regulations failed to sufficiently improve size structure. Since then, the increase of catch-and-release ethics have dramatically reduced harvest during the open season, and ODW has added yearly surveys that allow fisheries managers to better evaluate population trends. Ohio’s Lake Erie black bass populations are unlikely to be negatively impacted by newly introduced relaxed regulations (i.e., changing the seasonal closure to a one fish possession, 18 inch minimum size limit). Black bass harvest during the spawning season is unlikely to increase substantially with these regulation changes. However, current levels of bass fishing effort are near historical lows, and liberalization of regulations will allow additional fishing opportunities. The new regulations should expand angler opportunities and allow anglers to keep and weigh in a potential state record fish while conserving the bass population for generations to come.

AUTHORS: Richard R. Budnik, Ohio Department of Natural Resources, Division of Wildlife, Inland Fisheries Research Unit; Geoffrey B. Steinhart, The Ohio State University, Department of Evolution, Ecology and Organismal Biology, Aquatic Ecology Laboratory; Joseph D. Conroy, Ohio Department of Natural Resources, Division of Wildlife, Inland Fisheries Research Unit; Richard D. Zweifel, Ohio Department of Natural Resources, Division of Wildlife; Stuart A. Ludsin, The Ohio State University, Department of Evolution, Ecology and Organismal Biology, Aquatic Ecology Laboratory

ABSTRACT: Increased temperatures due to climate change will likely decrease the quality and quantity of habitat available to reservoir sport fish, although the extent of the effect will likely be variable by species. We developed bioenergetics models to estimate growth rate potential (GRP), a metric of habitat quality, for Largemouth Bass, saugeye, and White Crappie during a 13-year span (2005–2016) in three Ohio reservoirs that varied in productivity (summer 2012–2014 concentrations: chlorophyll a 7–55 µg/L; total phosphorus 21–106 µg/L). We contrasted these baseline measures of habitat quality with projected future changes in GRP and high-quality habitat (HQH; GRP > 0) availability under stabilizing (RCP 4.5) and increasing (RCP 8.5) carbon emission scenarios which estimate air temperatures will increase 2.5 and 4.8 degrees C by 2099. Our simulations predicted Largemouth Bass, saugeye, and White Crappie GRP would decrease an average of 0.001 g/g/day, 0.003 g/g/day, and 0.007 g/g/day, respectively, under RCP 4.5, and 0.005 g/g/day, 0.004 g/g/day, and 0.013 g/g/day under RCP 8.5. The average reduction of HQH was greatest for saugeye (20% loss) under RCP 4.5 and for White Crappie (45% loss) under RCP 8.5. Largemouth Bass HQH was the least affected with an average reduction of < 9% under both scenarios in all reservoirs. Temperature increases in the highest productivity reservoir led to the greatest reduction in habitat quality and quantity among reservoirs. These outcomes, as shaped by temperature changes, have the potential to influence not only the performance of individual fish but also will affect population dynamics, trophic interactions, and fish community structure.

AUTHORS: Elisa Baebler, Missouri Cooperative Fish and Wildlife Research Unit, The School of Natural Resources, University of Missouri; Craig Paukert, U.S. Geological Survey, Missouri Cooperative Fish and Wildlife Research Unit, The School of Natural Resources, University of Missouri

ABSTRACT: Downstream of hydropeaking dams, water depth and velocity fluctuate rapidly, which leads to short-term changes in physical habitat supporting aquatic organisms. While some fish species have been extirpated from flow-regulated systems, other species flourish, which may be related to the persistence of critical habitats complementary to these life histories. We used radio telemetry to evaluate the influence of season and streamflow on the habitat selection of two common, native fishes downstream of Bagnell Dam in central Missouri from April 2016 to June 2017. We studied Spotted Bass (Micropterus punctulatus), nest-guarding, sight feeding, habitat generalists and Shorthead Redhorse (Moxostoma macrolepidotum), fluvial dependent, migratory, benthic feeders. Spotted Bass selected moderate depths near submerged cover in all seasons and slow velocities during spring and summer. Conversely, Shorthead Redhorse preferred moderately deep and faster flowing habitats during spring and summer and used slow velocities and shallow depths during winter. Spotted Bass and Shorthead Redhorse selected velocity, depth, submerged cover, and distance to shore during stable and/or fluctuating flows, suggesting that fish may respond to streamflow over short time periods (daily). Spotted Bass used slow velocities (less than 0.4 m/s) in both fluctuating and stable flows, whereas, Shorthead Redhorse preferred fast velocities (greater than 1.0 m/s) in stable flows but did not select velocity during fluctuating flows. Shorthead Redhorse and Spotted Bass habitat selection illustrates that even native fish that prosper in regulated rivers have habitat requirements which may be better met through managing flow releases to maintain river habitats that support native fish of multiple guilds.

AUTHORS: Brandon J. Wu, Rene C. Reyes, Christopher L. Hart – U.S. Bureau of Reclamation; Kevin K. Kumagai, HTI-VEMCO USA, Inc.; Scott A. Porter, Michael R. Trask – U.S. Bureau of Reclamation

ABSTRACT: As an integral part of the Central Valley Project, the U.S. Department of the Interior, Bureau of Reclamation (Reclamation), Tracy Fish Collection Facility (TFCF; Byron, California) functions to salvage fish from Sacramento-San Joaquin River Delta water exported south by the C.W. “Bill” Jones Pumping Plant.  Predation by resident piscivorous fish is a contributing factor to fish loss at the TFCF and Striped Bass (Morone saxatilis) are generally considered the most prevalent piscivorous fish species within the facility.  To improve fish salvage and meet requirements mandated by the most recent National Marine Fisheries Service Biological Opinion, Reclamation is investigating the use of carbon dioxide (CO₂) as an anesthetic to remove predatory fish from the TFCF system.  The treatment of various water conveyance channels and components of the TFCF with CO₂ has demonstrated that elevated CO₂concentrations (50–350 mg/L) increase the number and size of Striped Bass in collection tanks (salvaged), suggesting that this application is feasible and effective.  In addition, acoustically tagged Striped Bass appeared to exhibit an avoidance response to elevated CO₂ concentrations.  The removal of acoustically tagged and wild Striped Bass during CO₂ treatment allowed for calculation of removal efficiency as well as estimation of Striped Bass population within the TFCF system at the time of testing.  Efforts are currently underway to estimate optimal CO₂ concentration for removal of Striped Bass based on removal efficiency and 96-hour post treatment survival.  Preliminary results suggest that the optimal CO₂ concentration for Striped Bass removal is approximately 165 mg/L.  Future efforts will focus on increasing removal efficiency in TFCF collection tanks as well as developing methods to direct piscivorous fish out of the facility to a location where there is no impact on salvageable fish.

AUTHORS: Dray Carl, Wisconsin Department of Natural Resources

ABSTRACT: Minimum length limits are the most commonly used regulation for protecting, enhancing, or manipulating black bass recreational fisheries, and most limits are generally set at appropriate lengths to provide harvest opportunities of larger individuals. However, in 1994, growth overfishing and angler outcry led fishery managers from the Wisconsin Department of Natural Resources (WDNR) to enact a 22-inch (559-mm) minimum size restriction on Smallmouth Bass in Wisconsin waters of Lake Superior. This regulation has essentially created a complete catch-and-release fishery for Smallmouth Bass, as no bass greater than 559 mm have been sampled in the field or observed in creel surveys during the 24-year period. Within Wisconsin waters of Lake Superior, Smallmouth Bass are largely localized to Chequamegon Bay, a 13,750-ha shallow (mean depth 8.5-m) embayment adjacent the Apostle Islands. I used time series data from standardized gillnet samples (3600’, graded mesh) and annual hook-and-line sampling to evaluate trends in population dynamics before and after the regulation change. I also evaluated Smallmouth Bass seasonal movement patterns in Chequamegon Bay using floy tag recapture histories. Immediately following the regulation, Smallmouth Bass size structure and abundance increased dramatically, presumably due to a large decrease in mortality. Overall, annual mortality is now 2.5 times lower than before the regulation change. However, growth remained constant throughout the time series data, suggesting adequate resources to support increased abundance of Smallmouth Bass in Chequamegon Bay. Results from this study provide an example of Smallmouth Bass population dynamic rates from a population suited for a “trophy” minimum length limit, information for adaptive management of Smallmouth Bass in northern climates, and numerous new questions for additional research. Potential community-level effects of increased Smallmouth Bass abundance in combination with an overall warming Lake Superior should be investigated.

AUTHORS: Stephen M. Tyszko, Jeremy J. Pritt, Joseph D. Conroy –Ohio Division of Wildlife

ABSTRACT: Using standard sampling methods for sport fish assessment allows powerful comparisons across time and space, if sample size is adequate. Biologists have begun evaluating precision and catch of sport fish surveys using North American standard methods (NASM) and have used resample methods to estimates sample sizes required to meet precision and catch objectives. The Ohio Division of Wildlife has collected standard sport fish surveys since 2003, providing an opportunity to further understand the performance of these methods. We evaluated relative standard error (RSE) and catch of stock-length individuals for NASM Largemouth Bass Micropterus salmoides electrofishing surveys  and NASM crappie (Pomoxis spp.) fyke net surveys in Ohio reservoirs 2003–2017.  We then used resampling methods to estimates sample sizes required to meet two sampling objectives: (1) for CPUE, achieve an RSE = 25; and, (2) collect at least 100 stock-length fish. We found that Largemouth Bass and crappie surveys generally met sampling objectives.  Resample analysis showed that the median number of samples required to meet objectives for Largemouth Bass surveys was 12 or fewer and the median for crappie surveys was 20 or fewer.  Our results support literature that shows NASM electrofishing can be used to obtain precise Largemouth Bass samples that meet catch objectives with a reasonable sample size.  Our crappie survey results contrasted literature that shows NASM fyke net methods required prohibitively large sample sizes to meet precision and catch objectives.  This analysis advances our understanding of sample size requirements for standard methods and highlights the importance of estimating sample size when designing standard surveys. Furthermore, we propose a standard resampling method for estimating sample size requirements.    

AUTHORS: Toniann D. Keiling, University of Illinois Urbana-Champaign; Michael J. Louison, McKendree University; Cory D. Suski, University of Illinois Urbana-Champaign

ABSTRACT: Global recreational fishing involves millions of anglers capturing millions of fish, and has the potential to negatively impact fish populations either through direct means (i.e. through incidental mortality or harvest), or through indirect means, such as the removal of specific behavioral types. At present, the specific mechanism(s) that define why fish strike fishing lures are unknown, as are how environmental factors influence catch rates. Understanding the factors that motivate fish to strike a lure will not only help predict catch rates, but will also help define how fisheries mortality and harvest can shape populations. The goal of this study was to define how behavioral type and prey availability interact to influence angling vulnerability, using largemouth bass as a model. To accomplish this goal, we first performed behavior assays on largemouth bass to place them along a ‘bold’ vs. ‘shy’ continuum, and then transferred fish to one of two ponds, one with a generous supply of prey (fathead minnows) and the other with no prey. Largemouth bass in the ponds were then angled for 8 days. Results indicated that prey availability only weakly influenced capture success in ponds. Rather, size (total length) was the strongest predictor of fish capture with larger fish more likely to strike lures, despite the fact that mean size varied by only 1.2 cm across captured and uncaptured individuals. Results are further discussed in the context of angling vulnerability, and how selective harvest may shape fish populations and aquatic ecosystems.