2022 Meeting Presentations

Oral Presentations

Names of presenters are underlined. Undergraduate students are noted with an asterisk and graduate students with a double asterisk.

Relationship of invasive carp eDNA detection to relative abundance and river discharge: a preliminary investigation in three Missouri River tributaries

Daniel A. James1, Landon L. Pierce1, Lacey Hopper2, and Tait Ronningen3

1U.S. Fish and Wildlife Service, Pierre, SD

2U. S. Fish and Wildlife Service, Bozeman, MT

3U.S. Fish and Wildlife Service, Bismarck, ND

The use of eDNA to detect organisms from water samples has become more widely used in recent years to monitor invasive species distributions. However, the ability of this technique to detect the presence of invasive species can vary among locations and it is unclear how species abundance and environmental conditions affects detection probability. Our objective was to compare eDNA detection probability with invasive carp relative abundance and river discharge to determine if either of these factors influence success of eDNA detection. In the summer of 2021, eDNA samples were collected from three tributaries of the Missouri River to detect the presence of invasive carp species (i.e., Silver Carp and Bighead Carp). Concurrent with eDNA sample collection, relative abundance measures for invasive carp were assessed using dozer trawl sampling. Water samples from two tributaries had 100% invasive carp eDNA detection, but detection was much lower for the third tributary. The low detection tributary had lower mean relative abundance (although not significant [anova: p>0.05]), while the other two tributaries had similar relative abundance. River discharge experienced a large increase due to a storm event one day before eDNA collection in the low detection tributary while river discharge was relatively stable and below long-term median values for the two high detection tributaries. Silver Carp relative abundance may potentially affect eDNA detection. Changes in river discharge before sample collection may be a significant factor that influences success of eDNA detections.

Tracking Movement of Invasive Silver and Bighead Carp in Three Missouri River Tributaries in Eastern South Dakota

Lindsey LaBrie1**, Jeff Wesner1, and Hugh Britten1

1University of South Dakota, Vermillion

This study uses passive telemetry and environmental DNA (eDNA) techniques to determine the geographic extent and movements of Silver and Bighead carp in eastern South Dakota. Fifty Silver Carp were caught using boat electrofishing in June 2021 and implanted with acoustic transmitters. A network of twenty-one passive telemetry receivers spanning approximately 358 rkm continuously detect fish movement. As of November 2021, 40 of the 50 tagged Silver Carp were detected on stationary receivers and/or by active tracking in the James River. Tagged carp were detected traveling a maximum of 33 rkm, (avg 4.9 rkm) from June to November 2021. In addition to telemetry, 119 eDNA water samples were collected in three sampling events in 2021 above and below major barriers to fish movement. Samples were filtered and extracted following Qiagen DNeasy Blood and Tissue Kit protocol. After extraction, gel electrophoresis showed no evidence of DNA contamination in field blank samples above and below each barrier in both rivers. Previously published species-specific primer sequences were used to detect the presence of Silver and Bighead carp eDNA in each extracted sample using qPCR. Results to date indicate that Silver Carp remained in a single tributary over the summer and fall, and that current barriers as well as drought conditions may limit the distribution of Silver Carp in eastern South Dakota.

Distribution and Habitat Use of Sturgeon Chub (Macrhybopsis gelida) in Missouri River Tributaries of South Dakota

Mitch Magruder1** and Mark Pegg1

1University of Nebraska – Lincoln, Lincoln

The Sturgeon Chub (Macrhybopsis gelida) is a benthic minnow (Family Cyprinidae) native to the Missouri River and lower Mississippi River drainages that is currently undergoing a 12-month finding through the U.S. Fish and Wildlife Service due to population declines. Key factors contributing to Sturgeon Chub population declines are associated with the development and operation of large reservoirs on rivers within its native range. Most notably, flow alterations, decreased turbidity, and a loss of connectivity by fragmented habitat pose threats to Macrhybopsis species in the Missouri River.  The Missouri River in South Dakota is highly altered with four out of the six mainstem dams residing within its state borders. South Dakota tributaries that have been less impacted by anthropogenic modifications may act as refugia for native fish populations, including the Sturgeon Chub. The extent of Sturgeon Chub populations is largely unknown within these tributaries. Additionally, little research has been conducted to investigate how Sturgeon Chub utilize tributary habitats. We sampled five major Missouri River tributaries in South Dakota, historically containing Sturgeon Chub, during the summers of 2020 and 2021 to determine their distribution and habitat use in the state. A total of 481 Sturgeon Chubs were collected in the Cheyenne, White, and Little White Rivers, with the White River containing 68% of the total catch. Spatial extent and habitat associations of Sturgeon Chub observed from this study will provide valuable information needed for the recovery and management of this species.

Seasonal Movements of Blue Suckers in the James River, SD

Tanner Carlson1**, Benjamin Schall2, and Dr. Jeff Wesner1

1University of South Dakota, Vermillion

2South Dakota Department of Game, Fish, and Parks, Sioux Falls

This project studied the seasonal movements of a rare fish, Blue Sucker (Cycleptus elongatus) in the James River, a large tributary of the Missouri River in South Dakota. Blue Suckers are impacted by fragmentation through dams and channelization on the Missouri River. As a result of this disruption to their migration route, Blue Suckers have been sampled within large tributaries of the Missouri. The goal of this project is to evaluate the use of large tributaries such as the James River by Blue Suckers. To evaluate the use of this tributary, we implanted acoustic receivers in 50 individuals ranging from 540 mm to 720 mm in total length. First year data indicate rapid movement of some fish, with tags detected up to 300+ km away. This suggests that Blue Suckers move actively throughout the Missouri River and its tributaries. Further data will resolve differences in use between sex, age, and body size of fishes to determine tributary use of Blue Sucker.

An updated distribution and evaluation of environmental influences on two at-risk fishes in the Black Hills, South Dakota

Kristina A. Morben1**, Chelsey A Pasbrig2, Jeremy L. Kientz3, Jacob L. Davis3, and David A. Schumann1

1University of Wisconsin- La Crosse, La Crosse

2South Dakota Game Fish and Parks, Pierre

3South Dakota Game Fish and Parks, Rapid City

Freshwater fish populations are at-risk of continued decline due to habitat degradation, overexploitation, and the expansion of non-native species. Limited ecological knowledge can hinder recovery efforts of non-game fishes despite them being disproportionately represented by species at-risk of extinction. Lake Chub (Couesius plumbeus) and Longnose Sucker (Catostomus catostomus) were once abundant and widespread throughout the Black Hills Management Area; however, recent surveys documented extensive declines. To better inform management, we updated the current distribution and described the local population structure of these fishes throughout the Black Hills Area. We identified several abiotic and biotic factors that influence detection and occurrence patterns of these poorly studied species. Fifty-five stream reaches (500m) were sampled using backpack electrofishing based on historical records (1893-1989), recent records (1990-present), and exploratory criteria (i.e., nearby known sites). Instream habitat and riparian metrics were measured at eleven equidistant points along the stream reach to describe habitat conditions. Detection histories were developed using a hierarchical framework within which three electrofishing transects (100m) were sampled per stream reach (i.e., 165 total sampling transects). Detection (e.g., temperature, conductivity, turbidity) and occupancy covariates (e.g., water velocity, instream structure, and aquatic vegetation) were used to construct competing candidate models that were fitted by maximum likelihood in a Markov chain-Monte Carlo approach. Longnose Sucker (n=139) were detected at transects only in Crow Creek and Spearfish Creek and Lake Chub (n=252) were detected at transects only in Boxelder Creek and its tributary Bogus Jim and represented ~2% of the total fish captured. Longnose Sucker detection probability (0.85) was influenced by dissolved oxygen, in contrast Lake Chub detection probability (0.59) was not influenced by the measured covariates. A complete understanding of the distribution and environmental influences on both species will inform future management decisions, such as reintroductions or habitat restoration for these native fish species.

An Overview of the 2013-2014 National Rivers and Streams Assessment in North Dakota

Joshua Wert1 and Aaron Larsen1

1North Dakota Department of Environmental Quality, Bismarck

The National Rivers and Streams Assessment (NRSA) is one component in an ongoing series of water quality assessment surveys sponsored by the Environmental Protection Agency (EPA), known as the National Aquatic Resource Surveys (NARS).  In North Dakota, the Department of Environmental Quality’s (NDDEQ) Division of Water Quality participates in these surveys, designed to produce statistically valid ecological estimates on the condition of the nation’s rivers and streams. This presentation specifically summarizes condition estimates for the State of North Dakota during the 2013-2014 assessment cycle. Forty-eight (48) sampling sites were randomly selected in North Dakota, including small, 3rd Strahler order streams as well as large, boatable waterbodies such as the Red River of the North and the Missouri River. Each sampling location was delineated using standardized field sampling protocols to collect data relevant to current biological (e.g., fish, macroinvertebrates), chemical (e.g., specific conductance, nutrients) and physical (e.g., substrate, fish habitat) condition.

Effects of Seasonal Hypoxia on Macroinvertebrate Communities in a Small Reservoir

David Lucchesi1, Steven Chipps2, and David Schumann3

1South Dakota Game, Fish and Parks, Sioux Falls

2USGS, South Dakota Cooperative Fish & Wildlife Research Unit, Dept. of Natural Resource Management, South Dakota State University, Brookings

3Department of Biology, University of Wisconsin – La Crosse, La Crosse

Localized hypoxia can reduce available habitat, restrict movement and limit the abundance of aquatic invertebrates. Cultural eutrophication coupled with the effects of climate change is likely to increase the frequency and extent of hypoxia in aquatic ecosystems, yet little is known about how oxygen gradients in small reservoirs influence spatial distribution and abundance of aquatic invertebrates. We evaluated the effects of environmental and biological attributes on seasonal and spatial variation of macroinvertebrates and explored how hypoxic conditions influenced littoral, benthic and pelagic macroinvertebrate communities in Lake Alvin, South Dakota.  We collected data on reservoir conditions in conjunction with macroinvertebrate sampling from May to October, 2009-2011 and applied an information theoretic approach to evaluate factors affecting invertebrate abundance. Hypoxic conditions were present from May to September in the lacustrine zone impacting 10-39% of the water column.  Benthic invertebrates were typically absent from the lacustrine zone during periods of severe hypoxia and were most abundant in the shallow, well-oxygenated riverine zone.  Littoral invertebrates were negatively related to percent of the water column that was hypoxic suggesting that fish, confined to shallow water by hypoxia, were consuming a larger portion of littoral invertebrates in their diets. Cladocera and Copepoda densities were influenced primarily by water depth and monthly precipitation. The larger size of Daphnia in the deeper, more hypoxic transitional and lacustrine zones suggest that low oxygen concentration may provide a refuge from fish predation. This study demonstrated that spatial variation in near-bottom oxygen concentrations were important predictors of macroinvertebrate and zooplankton abundance and size structure in Lake Alvin and that macroinvertebrates, particularly benthic and littoral invertebrates, could benefit from measures taken to reduce summer hypoxia.

Reversing What Time has Taken Away: Mother Nature’s Experiment with Cove Connection in Harlan County Reservoir

Jenna Ruoss1**, Brian Mason2**, Melissa Wuellner2, and Keith Koupal3

1University of Nebraska – Lincoln, Lincoln

2University of Nebraska at Kearney, Kearney

3Nebraska Game and Parks Commission, Kearney

Coves are part of the mosaic of habitats in many U.S. reservoirs and may be important for some species and life stages of fish.  However, erosion and lateral drift of sediments may lead to cove disconnection from the main reservoir.  The duration of disconnection may vary depending on sediment berm height and reservoir elevation.  Water elevations are expected to be more dynamic with future climate change.  Our four-year study (2017 – 2020) of seven coves of Harlan County Reservoir, Nebraska, across three seasons (spring, summer, and fall) provided an opportunity to compare fish communities between coves that have remained connected to the main body of the reservoir over time due to human interventions to those of coves that have been intermittently or completely disconnected to the reservoir over the past ten years.  Further, we were able to evaluate changes in cove fish communities following substantial increases in reservoir water elevations in 2019 that reconnected all of the disconnected coves to the main body of the reservoir without human intervention.  Taxa richness and diversity were lower in the intermittently connected and disconnected coves compared to the connected coves in 2017 and 2018, and a few species were found only in or in higher abundance in one cove type versus the other.  However, fish communities notably shifted in intermittently connected and disconnected coves following the reconnection event in 2019.  In fact, fish communities became more similar between the three cove types between 2019 and 2020.  Results from this study underscore the importance of coves as important habitats for some species and provide insights as to how fish communities may change when coves are reconnected, whether by human interventions or more variations in reservoir elevation due to climate change.

Discontinuity theory and landscape-level management of aquatic systems

Julia Hampton1** and Mark Kaemingk1

1Department of Biology, University of North Dakota, Bismarck

Landscape-level changes in the quantity and distribution of surface water are becoming more frequent. Receding water can limit habitat while expanding water can increase habitat for aquatic-dependent species, potentially restructuring aquatic communities. We believe we can detect these changes by identifying discontinuities in waterbody size distributions. Discontinuities are recognizable as abrupt shifts in waterbody size distributions on the landscape. These shifts could reflect significant changes in ecological patterns and processes occurring at distinct spatial and temporal scales. The Prairie Pothole Region (PPR) is a naturally dynamic system with a long history of fluctuating wet-dry cycles. This provides an excellent model system to apply discontinuity theory to detect regime shifts in aquatic systems. We will use remote sensing techniques to quantify waterbody surface areas during drought and deluge periods (1993-2018) within three PPR study sites that vary in latitude. We will then look for statistically significant gaps, or discontinuities, among waterbody size distributions. We expect discontinuities, between drought and deluge periods, to reflect abrupt changes in water quality and aquatic communities. Detecting these discontinuities will aid in our understanding of how the PPR has recently shifted to more aquatic-dominated communities as opposed to avian-dominated communities. Discontinuity methods allow us to place lentic systems on a continuum and capture essential nonlinear transitions that were previously difficult to detect, providing crucial insight for the management of dynamic aquatic ecosystems.

Otolith Microchemistry Reveals Contribution of Hatchery-Origin Walleye in Lake Oahe, South Dakota

Mark Fincel1 and Cameron Goble1

1South Dakota Game, Fish and Parks, Fort Pierre

Determining provenance of fishes has long been sought after and plays an important role in evaluating hatchery stocking practices. In lower Lake Oahe, South Dakota, recent fingerling Walleye stockings have coincided with increased relative abundance (catch-per-unit-effort; CPUE) of catchable-size Walleye. However, it is unknown if these fish originated from hatchery stockings or were produced naturally. Thus, we used otolith microchemistry to distinguish between natural- versus hatchery-origin Walleye in Lake Oahe. In fall 2020, during South Dakota Game, Fish and Parks standard adult population surveys, we collected adult Walleye (n=363) to determine fish origin. We used published age-0 Walleye microchemical signatures to assign adult Walleye to known origin and used a k-sample nearest-neighbor discriminant analysis to determine the accuracy at which the fish were assigned. Additionally, we compared length-at-age of Walleye between both origins and examined changes in Walleye CPUE within the lake following recent stockings. Walleye were assigned origin with high accuracy (~98%). Age-1 through age-3 Walleye represented year classes that included hatchery contributions and 35% (age-1, 2019 year-class), 50% (age-2, 2018 year-class), and 23% (age-3, 2017 year-class) of the fish sampled within these age classes were of hatchery-origin. No fish were classified as hatchery-origin from year classes that did not receive Walleye stockings. Hatchery- versus wild-origin Walleye exhibited no difference in length-at-age for all stocked year classes. From 2002 through 2021, age-2 Walleye CPUE on lower Lake Oahe approached or exceeded that observed in upper Lake Oahe in only 7 years. Of those, 3 were years when lower Lake Oahe was stocked. Thus, it appears that hatchery-origin Walleye are well represented in the lower Lake Oahe Walleye fishery, appear to be of equal size to naturally produced fish, and stockings are producing Walleye abundances that approach or exceed that which is produced naturally in upper Lake Oahe.

17β-estradiol Sex Reversal of Brown Trout 

Jill M. Voorhees1, Elizabeth R. J. M. Mamer2, Daniel J. Schill3, and Michael E. Barnes1

1South Dakota Game, Fish and Parks, Spearfish

2ERJMM Research, LLC, Nampa, ID

3Fisheries Management Solutions, Inc., Boise, ID

Hormones have been used to change sex in many fish species, but information on brown trout (Salmo trutta) is lacking. This study compared the effectiveness of two different 17β-estradiol (estradiol)/concentrations (20 mg/kg and 30 mg/kg) fed to brown trout for 60 days beginning at initial feeding. Feminization, evaluated at 456 days post-initial feeding, was 84% and 86% females in the 20 mg/kg and 30 mg/kg treatments respectively, which were not significantly different, but both were significantly higher than the 47% females observed in the control group which was did not receive dietary estradiol. At the end of the 60-day treatment period gain, percent gain, and feed conversion ratio, individual fish weight and total length were all significantly greater in the control tanks than either of the estradiol treatments. Mortality ranged from 1.0 to 2.4% among the treatments but was not significantly different. After 105 days, gain, percent gain, and feed conversion ratio were not significantly different among the treatments. This study is the first to document the successful sex reversal of brown trout using estradiol. While the estradiol treatments used in this study did not lead to complete feminization, the 85% feminization rates produced may be high enough to produce fish for use by fisheries managers.

Angling of Hybrid Sunfish from a Hatchery Pond with Potential Implications for Community Fisheries

Brian G. Blackwell1, Matthew J. Ward2, and Todd M. Kaufman1

1South Dakota Department of Game, Fish and Parks, Webster

2South Dakota Department of Game, Fish and Parks, Waubay

Hatcheries are frequently called upon to produce catchable-sized fish for stocking community fishing ponds. Hybrid sunfish [male Bluegill (Lepomis macrochirus) X female Green Sunfish (L. cyanellus)] have attributes that potentially make them attractive for use in community fishing ponds. We assessed initial angler catch rates of 100 stocked hybrid sunfish in a 0.12-ha hatchery pond and after being subjected to angling (four, 1-hr catch-and-release fishing events with five anglers). We also investigated whether catch rates would change following a supplemental stocking of an additional 100 hybrid sunfish (four, 1-hr catch-and-release fishing events with five anglers). The anal fin of each fish in the second stocking was hole punched to differentiate them from those of the first stocking and fish caught by anglers were hole punched in the caudal fin each time they were caught before being released back into the pond. Angler catch rates were highest during initial fishing events that followed stocking (9.2 fish/angler hr and 18.0 fish/angler hr) and substantially declined in subsequent events (< 3.4 fish/angler hr). Catches of the newly stocked fish and previously stocked fish contributed to the high catch following the supplemental stocking. Most (80%) of the fish were caught in the first 30 minutes of each event and 45% were caught during the first 10 minutes. Anglers were able to catch 88% of the fish from the first stocking and 67% from the second stocking at least once. No mortality occurred during the study as all fish were recovered when the pond was drained. Our results suggest that hybrid sunfish will potentially provide high initial catch rates following stocking into community ponds, but managers should expect reduced catch rates following initial fishing even without harvest. Additional stocking will be needed to provide periodic increases in angler catch rates even without harvest.

Evaluating a Three-Fold Continuum of Fry Stocking Density for Rearing Walleye in Lined Ponds

Matthew Ward1 and Chad Haabala1

1Blue Dog State Fish Hatchery, South Dakota Game Fish and Parks, Waubay

Fry stocking density can affect harvest metrics for fingerling walleye (Stizostedion vitreum) reared in drainable ponds, but few studies have examined these relationships with the use of elevated walleye fry stocking densities in lined ponds. Correlation and regression analyses were used to assess how a three-fold change in walleye fry stocking density (234,375 to 703,125 per ha) relates to harvest metrics and length of the culture period, as well as the tradeoff experienced between walleye size and harvest density in 0.32-hectare lined ponds over a nine-year period at Blue Dog State Fish Hatchery, South Dakota.  As walleye fry stocking density increased, so did harvest metrics for both number (r = 0.85, P < 0.01) and yield (r = 0.81, P < 0.01).  Length of the culture period varied between 24 and 35 days and was negatively related to stocking density (r = -0.66, P < 0.01).  The linear relationship between walleye harvest density and yield was highly correlated (r = 0.95, P < 0.01) with highest values measuring 617,625 walleye and 173 kilograms per hectare.  Harvest density (number per hectare) explained 61% of the variation in walleye size (P<0.01) and exhibited a decreasing curvilinear relationship such that continued increases in harvest density resulted in smaller reductions in fish size.  Increasing fry stocking density from 234,375 to 703,125 per hectare in lined ponds coincided with increased rearing efficiencies (number, yield, and time) and minimal reductions in walleye size once harvest density exceeded 300,000 per hectare.

Does local knowledge matter? Explaining catch rates among angler groups of three northern Wisconsin lakes

Michael J. Lant1**, Greg G. Sass2, Zachary S. Feiner3, and Derek H. Ogle4

1University of North Dakota, Bismarck

2Escanaba Lake Research Station, Wisconsin Department of Natural Resources, Boulder Junction

3Center for Limnology, University of Wisconsin-Madison, Madison

4Department of Mathematical Sciences and Natural Resources, Northland College, Ashland, WI

Understanding influences of angler proximity on fisheries resources, the distances anglers are willing to travel, their success rates after they arrive, and seasonal ecological patterns could influence fisheries resiliency, license sales, and management. The Northern Highlands Fishery Research Area near Boulder Junction, Vilas County, WI maintains a compulsory creel census for five research lakes. Using ZIP code information from angler residence, we developed anglershed maps to discern species-specific (muskellunge, smallmouth bass, walleye, yellow perch) angler proximity to three lakes and categorized discrete angler groups (local, non-local, non-resident) based on proximity. We used creel census data during 2014-2019 to test for differences in angler catch rates and effort among angler groups. Among all angler groups and species, catch rate and effort were generally equal with minor species-specific differences. Our hypothesis of “local knowledge” being the primary influential variable for catch rate was not supported. Our results suggest a need to manage for all angler groups due to generally equivalent species-specific catch rates and effort independent of proximity to fishing opportunities.

Angler residency changes during a pandemic

Greg Simpson1

1South Dakota Game, Fish and Parks, Rapid City

The Covid-19 pandemic redefined normalcy for many throughout the world.  Within the United States, various states implemented protocols as emergency measures to curtail the spread of this virus.  In South Dakota, the governor presented a limited action guidance that asked individuals to follow simple guidelines for most individuals (e.g., stay six feet apart, wash hands, stay home when sick).  Other than these strategies, the State of South Dakota was open for visitors.  In this study, we looked at the potential changes in angler demographics during this period.  Anglers were asked a series of questions (including their home zip code) concerning their fishing trip via a self-service kiosk questionnaire before, during and post-pandemic (years 2019, 2020, 2021).  Data used for this study was from a kiosk positioned within Custer State Park, a highly visited park in the Black Hills of South Dakota. The total number of reported zip codes was 122 in 2019, increasing to 181 during the pandemic of 2020 and remaining steady at 182 the year after. Through GIS, pre-pandemic data show many users coming from the east with a few towards the northwest part of the U.S.  During the pandemic, there was a large expanse of reported zip codes across the U.S., and this continued the following year. Anglers to the Black Hills increased during throughout the Covid pandemic with potential long-term effects.  While not all visitors come to the Black Hills area to fish, and we recognize that compliance is not one hundred percent, there were strong increases in the amount and extent of visitation of anglers to the area.  This information may prove useful in identifying potential needs, such as, regulation guidance or species presence at certain waters for these new users.

Estimating predation on newly stocked Chinook Salmon (Oncorhynchus tshawytscha) using acoustic telemetry

Dylan Gravenhof1 and Melissa Wuellner2

1South Dakota Game, Fish and Parks, Fort Pierre

2University of Nebraska – Kearney, Kearney

Lake Oahe is a recreationally important reservoir on the Missouri River in central South Dakota. South Dakota Department of Game, Fish and Parks (SDGFP) manages Lake Oahe as a two-tiered cool/warm water and cold-water fishery. Chinook Salmon Oncorhynchus tshawytscha is a species frequently targeted by anglers and provides a unique cold-water fishing opportunity in the Midwest. Chinook Salmon were first introduced into Lake Oahe as early as 1979 and a spawning program initiated by SDGFP has maintained the population as no natural reproduction has been documented. Immediate post-stocking survival may be one factor affecting the stocking success and eventual recruitment of juvenile salmon to the sport fishery. In spring 2021, 50 juvenile salmon were implanted with Innovasea® V5D 180-khz acoustic transmitters capable of identifying a predation event on a tagged individual. Additionally, passive receiver arrays were deployed in both Spring Creek and Whitlock Bay on Lake Oahe to document any predation events. At least 13 of 25 (52%) tagged salmon stocked in Whitlock Bay were consumed by a predator. In contrast, only 5 of 23 (22%) tagged fish were consumed in Spring Creek. Thus, predation rates differ by stocking location. Further research will quantify predations rates in these same locations during a second year and identify factors between the two locations that may influence predation rates. If high predation rates persist, alternative stocking strategies may be warranted.

Smallmouth Bass Predation on Stocked Age-0 Walleye in Lake Oahe, South Dakota

Kyle Olivencia1**, Emily Grausgruber1, Mark Fincel2, and Michael Weber1

1Iowa State University – Department of Natural Resource Ecology and Management, Ames

2South Dakota Game, Fish, and Parks, Fort Pierre

Walleye Sander vitreus is an economically important sportfish commonly stocked to supplement populations. Increases in Smallmouth Bass Micropterus dolomieu abundance throughout the Midwest in recent decades has prompted concerns regarding predation on stocked Walleye. However, the timing and extent of predation is unknown. Our objectives were to estimate the timing and duration of Smallmouth Bass predation on stocked Walleye, frequency of occurrence and percent composition by weight of Walleye in Smallmouth Bass diets, and the percent of stocked Walleye consumed by Smallmouth Bass. Smallmouth Bass diets were collected May (pre-stocking) and June-September (post-stocking) 2019 and 2021 from three bays in Lake Oahe, two of which were stocked with Walleye whereas one was not and served as a reference. We estimated Smallmouth Bass population abundance using Schnabel capture-recapture models and used bioenergetics to estimate the percent of stocked Walleye consumed. Walleye were only found in Smallmouth Bass diets post-stocking and only in stocked bays. Post-stocking in 2019, at least one Walleye occurred in 11.4% of Smallmouth Bass diets from Spring Creek (n=281) and 4.9% from Okobojo Bay (n=226). Daily mean percent composition by weight (± SD) of Walleye in diets peaked within 3 days post-stocking (DPS) (Spring: 1 DPS – 38.6% ± 45.1%; Okobojo: 3 DPS – 5.8% ± 15.7%), rapidly declined after 10 DPS, and was 0% after 25 DPS. The estimated percent (± 95% CI) of stocked Walleye consumed by Smallmouth Bass was 6.6% (2.2%) in Spring Creek and 0.6% (0.3%) in Okobojo Bay, suggesting Smallmouth Bass consume a small percentage of stocked Walleye. In 2021, no age-0 Walleye were observed in the diets prior to stocking. Post-stocking, we commonly observed age-0 Walleye in diets during the first few days post-stocking. Managers should consider up to 6% loss in stocking fingerling Walleye in lakes with resident Smallmouth Bass.

Assessment of Isotope Shifts in Northern Pike in Response to Increased Rainbow Trout Stocking Length

Jeremy L. Kientz1

1South Dakota Game, Fish and Parks, Rapid City

Pactola Reservoir in the Black Hills of South Dakota has historically been managed as a coldwater fishery and is stocked annually with Rainbow Trout Oncorhynchus mykiss. In 2003, Northern Pike Esox lucius were first sampled in fisheries surveys by South Dakota Game, Fish, and Parks (SD GFP) and have since become an established predator. Due to concerns of direct predation on stocked catchable (275 mm) Rainbow Trout, SD GFP partnered with South Dakota State University on a research project which evaluated Northern Pike diets and isotopes. The results of that study showed that fish smaller than 600 mm had δC13 isotope values similar to centrarchid prey species, whereas δC13 values for 600 mm and larger fish were similar to stocked Rainbow Trout. In response to this research and to reduce predation by Northern Pike, SD GFP increased the Rainbow Trout stocking size in Pactola Reservoir from 275 mm to 381 mm. The objective of this study was to evaluate Northern Pike isotope changes in response to the increased Rainbow Trout stocking size. Northern Pike (n=42) were captured in May 2021 with sizes ranging from 457 mm to 1,021 mm. δC13 values in Northern Pike smaller than 700 mm were similar to the centrarchid prey values seen in the previous study, suggesting that stocked Rainbow Trout had not become a major diet item for 700 mm and smaller individuals. This data was supported by an analysis of variance (ANOVA) among 100 mm size bins which revealed that significant differences in δC13 were detected between the 700 mm and 800 mm size bins, but not among 700 mm and smaller size bins. Furthermore, a piecewise linear regression technique in program R revealed a breakpoint value of 716 mm. These results indicate that the length at which Northern Pike prey upon stocked Rainbow Trout has increased by over 100 mm following the increase in trout stocking length.

Population Size and Survival of Shovelnose Sturgeon in Lake Sharpe, South Dakota

Cameron Goble1, Mark Fincel1, Chelsey Pasbrig2, Dylan Gravenhof1, and Hilary Morey2

1South Dakota Game, Fish and Parks, Fort Pierre

2South Dakota Game, Fish and Parks, Pierre

Located on the Missouri River in central South Dakota, Lake Sharpe holds an isolated population of Shovelnose Sturgeon Scaphirhynchus platorynchus. Presently, the state of South Dakota does not allow harvest of any sturgeon species from the Missouri River or its tributaries. However, little research has been done examining the status of the Lake Sharpe population leading fisheries managers to question whether it might support a limited recreational sport fishery. Beginning in the spring of 2017-2019, 1,251 adult Shovelnose Sturgeon were collected and marked with uniquely numbered floy tags. Of these, 55 were implanted with acoustic telemetry tags and monitored over the course of 2 years. A mark-recapture estimate of population size suggests approximately 7,000 (LCI = 5,836, UCI = 8,444) adult Shovelnose Sturgeon inhabit Lake Sharpe. Annual survival of adult Shovelnose Sturgeon was estimated at 83.4%. Angler interest in harvesting Shovelnose Sturgeon is limited with 20% of interviewed anglers indicating that they would harvest a Shovelnose Sturgeon if given the opportunity. Given the robust population size and low natural mortality, it appears that the Lake Sharpe Shovelnose Sturgeon population could support a limited recreational fishery.

Black Crappie Population Dynamics and Influence of Gizzard Shad in Prairie Impoundments of Western South Dakota

Gene Galinat1 and Bill Miller1

1South Dakota Game, Fish and Parks, Rapid City

Black crappies are a popular sportfish common to reservoirs in western South Dakota. We used trap net data from 2010 to 2020 to evaluate population characteristics (i.e. recruitment, condition, growth and size structure) from seven different prairie reservoirs. In addition, introductions of gizzard shad into western South Dakota reservoirs have been accomplished in attempt to provide a more consistent prey for sportfish. Negative effects gizzard shad can have on fish communities have been documented, therefore, we also evaluated black crappie populations between reservoirs having shad present or absent and within reservoirs before and after gizzard shad introductions occurred. We found black crappie populations in western South Dakota are characterized by variable recruitment and generally experience some level of recruitment failure. The lakes with gizzard shad did show larger length-at-age and higher PSD-P values after the introductions. Gizzard shad, however, did not appear to affect black crappie abundance and mean condition. Our results indicate the addition of gizzard shad improved size structure without negatively affecting other characteristics of black crappie populations in western South Dakota.

Angler Use of Trophy Northern Pike in Lake Oahe, ND

Paul Bailey1, Justen Barstad1, Dave Fryda2, and Russ Kinzler2

1North Dakota Game and Fish Department, Bismarck

2North Dakota Game and Fish Department, Riverdale

Lake Oahe has long supported one of North Dakota’s premier trophy (≥ 1 meter in length) northern pike fisheries. However, information on angler use and guidance as to the level of exploitation that could be supported while maintaining the present quality of this fishery was lacking. The North Dakota Game and Fish Department (NDGF) conducted a tagging study to estimate angler exploitation of trophy northern pike in the North Dakota portion of Lake Oahe and applied guidance from previous trophy esocid research to estimate the level of exploitation that could be sustainably supported. We observed a 7.7% annual exploitation rate (90% CI: 5.2-10.3%) of trophy northern pike in Lake Oahe and estimated that an annual exploitation rate ≤ 20.3% is likely to maintain the present quality of this fishery. Together, this information indicates that the NDGF’s current harvest regulations are compatible with the long-term sustainability of trophy northern pike fishing in Lake Oahe.

Poster Presentations

Names of presenters are underlined. Undergraduate students are noted with an asterisk and graduate students with a double asterisk. Posters are arranged alphabetically by first author’s last name.

Diet Overlap Between Sport Fish in a Large South Dakota Glacial Lake

Lauren Allex1*, Logan Cutler1**, Brian Blackwell2, and Alison Coulter1

1South Dakota State University, Brookings

2South Dakota Game, Fish, and Parks, Webster

Walleye (Sander vitreus) show overlap and potential competition with other sport fishes in South Dakota, especially in diet. However, the amount of overlap for food resources may vary among lakes and seasons and may not necessarily indicate competition in situations where resources are very abundant. In many northern US lakes, potential competitors with Walleye include Northern Pike (Esox lucius) and Smallmouth Bass (Micropterus dolomieu) which may all consume prey fishes as adults. Our objective was to determine the amount of diet overlap between Walleye and Smallmouth Bass in Lake Kampeska, South Dakota. We used boat electrofishing and gill nets to collect a variety of sizes of each species in the summer and fall of 2021. Stomachs were removed for diet analysis, which provides an immediate measure of potential competition, and white muscle samples were taken for stable isotope analysis that provide a longer-term (2-3 months) assessment of potential competition. Smallmouth Bass diets were dominated by crayfish, while the Walleye diets consisted mostly of prey fish resulting in Walleye having enriched δ13C signatures. δ 15N signatures were similar between species. Based on the information gathered, potential competition appears minimal. This information can be used to determine which prey types are most important for each species, and which items may represent a source of competition. Biologists also can use this information to understand potential barriers to Walleye growth and condition. Future work will also compare diets of Walleye and Smallmouth Bass to Northern Pike across additional seasons. 

Aging Structure Comparisons and Growth Modeling for Blue Sucker in the James River, South Dakota

Tanner Carlson1**, Benjamin Schall2, and Dr. Jeff Wesner1

1University of South Dakota, Vermillion

2South Dakota Department of Game, Fish, and Parks, Sioux Falls

This project studied the age comparisons of two commonly used hard structures for Blue Suckers sampled in the James and Missouri Rivers in South Dakota. Previous studies have suggested fin ray age estimates are reliable estimates to use for Blue Suckers, where other more recent studies have raised concerns over the accuracy of fin ray ages compared to traditionally reliable estimates of otoliths. This study compared these two structures by sampling 80 adult Blue Suckers and compared the fin ray age estimate to the otolith age estimate of each fish. Using otolith ages and length data, Von Bertalanffy and Gompertz growth models were developed and compared using a Bayesian mixed modeling approach. The results of our study showed that fin rays underestimate Blue Sucker ages when compared to otoliths at older ages. This study supports recent studies that suggest that fin ray age alone does not give a reliable estimate of age for Blue Suckers.

Evaluating Effects of Partial Wetland Disconnection on Walleye Diet and Prey Availability

Logan Cutler1**, Dr. Brian Blackwell2, and Dr. Alison Coulter1

1South Dakota State University, Brookings

2South Dakota Game, Fish and Parks, Webster

Wetlands are critical habitats for fish and are closely tied to fishery health. Wetlands are often productive habitats that can provide abundant food sources for fish. Barriers limiting fish access to wetlands and other crucial habitats have been cited as the single greatest threat to fishes in the United States. Lake Kampeska, a large glacial lake in northeastern South Dakota, was modified in 2001 with a V-notch weir partially separating the lake from a large section of shallow open water wetland. Our objective was to determine differences in Walleye diets and prey availability in Lake Kampeska and its partially disconnected wetlands. We used boat electrofishing and gill nets to collect Walleyes for diet analysis from both habitats during summer and fall of 2021. We collected prey fish during the same time periods using mini-fyke nets in both habitats. Walleye diets will be compared seasonally and between habitats using the mass of diet items and a prey importance index. Data collected during summer 2021 showed the wetland prey fish community had higher taxa richness (R = 10), Shannon diversity (H = 0.817), and evenness (J = 0.355) than the lake (R = 8, H = 0.132, J = 0.063). Walleye diet and prey fish collection will continue in spring, summer, and fall of 2022, and spring of 2023. Higher prey abundance, a more diverse prey community, and greater mass of diet contents in either habitat would be indicative of potential faster Walleye growth from wetland access. Results of this study will help to inform managers on the potential benefits of barrier removal and wetland restoration as it relates to Walleye growth and survival.

Living in a gradient: The influence of water temperature variation on development, settling time and survival of Pallid Sturgeon larvae in the Missouri River

Maria E. Erceg1**, Steven R. Chipps2, Daniel A. James3, and Patrick J. Braaten4

1South Dakota State University, Brookings

2U.S. Geological Survey, South Dakota Cooperative Fish and Wildlife Research Unit, Brookings

3U.S. Fish and Wildlife Service, Pierre, SD

4U.S. Geological Survey, Fort Peck, MT

Pallid Sturgeon (Scaphirhynchus albus) are a federally endangered species experiencing widespread reproduction and recruitment failures. Recruitment failure is hypothesized to be caused by habitat modifications made to the Missouri River that disrupt connectivity and alter temperature profiles downstream of constructed dams. Hypolimnetic releases from Missouri River dams affect the temperature downstream, creating colder conditions during the downstream drifting phase. Understanding the influence of water temperature changes on larval development is crucial for recovery efforts. In this study, we evaluated the effects of temperature increases ranging from 0.284°C to 1.477°C day-1 on energy use, settling behavior, and growth rate of endogenously feeding Pallid Sturgeon larvae. Settling rate of larvae was positively related to heating rate and ranged from 5 to 8 days post hatch at heating rates of 0.284°C to 1.477°C day-1. Extending the drift time by 3 days would extend the drift distance by approximately 150 km based on average river velocity. Our data will help inform proposed surface-water releases at Fort Peck Dam to improve larval survival in the Upper Missouri River.

Effects of Hester-Dendy Sampler Designs on Zebra Mussel Colonization

Amy Gebhard1, Brandon Vanderbush1, and Chris Longhenry1

1South Dakota Game, Fish and Parks, Chamberlain

Zebra Mussels (Dreissena polymorpha) were first detected in Lewis and Clark Lake in the fall of 2014. In 2017, South Dakota started monitoring zebra mussels in Lewis and Clark Lake.  Three plate Hester-Dendy samplers with 0.26 m2 surface area were deployed at various locations in Lewis and Clark Lake to monitor density and spread within the reservoir and extensive sampling was conducted within the Lewis and Clark Marina. In 2019, South Dakota expanded its sampling effort and adopted a four plate, 0.185 m2 surface area Hester-Dendy sampler for zebra mussel detection and monitoring statewide. Effects of sampler design on colonization rates are unknown and is the impetus for this study. To evaluate effects of sampler design, twenty pairs of both sampler types were deployed in the Lewis and Clark Marina in May 2021 and five pairs were retrieved monthly in July through October. Colonization rates were not significantly different between the two designs (t-value = -0.66, df=19, p value =0.52). Mean length of attached mussels was also similar for the two designs (t-value 1.3, df=19, p value =0.21). Overall, our results suggest that the two different designs can be used interchangeably in South Dakota waters for estimating mussels/surface area.

An Evaluation of Fish Use of Habitat Structures in Sandy Channel State Recreation Area Pond #2, Nebraska

Abby Kessler1*, Logan Dietrich1**, Melissa Wuellner1, and Keith Koupal2

1University of Nebraska at Kearney, Kearney

2Nebraska Game and Parks Commission, Kearney

Reservoirs are often devoid of habitat due to sedimentation and decomposition of complex natural structures.  Additions of habitat have been a long-standing practice of fisheries managers, but evaluations are often lacking, especially in larger reservoirs.  Smaller impoundments provide an opportunity to assess the additions of habitat.  The objective of this study was to compare fish use and water quality around added Georgia cubes and existing submerged trees, and control (bare) areas in one sand pit pond in south central Nebraska. Three Georgia cube complexes were placed in September 2020.  An underwater camera was used to record fish over each cube complex and three randomly selected bare and submerged tree areas for five minutes across four seasons.  Water quality measurements were taken at each location each season.  Counts of fish and water quality were compared across habitats using an analysis of variance (ANOVA).  Fish counts were higher in summer and fall than winter or spring (F = 4.74, p = 0.01); fish were more abundant around cube complexes than bare or downed trees (F = 6.70, p = 0.01). No differences were noted in water quality between habitats.  Overall, the results of this study show that fish are attracted to and use a novel, artificial structure more than existing natural habitat and that the additions of these habitats do not alter water quality, at least in the short term. Further research is needed on the long-term changes in fish populations to assist in the planning and evaluation of habitat management plans.

Invasive Carp Movement and Distribution in Tributaries of the Missouri River

Jason Kral1, Dan James2, and Landon Pierce2

1U.S. Fish and Wildlife Service, Yankton, SD

2U.S. Fish and Wildlife Service, Pierre, SD

Invasive carp are well established in the Missouri River Basin up to Gavins Point Dam, South Dakota/Nebraska. Flooding events are thought to result in increased upstream movements of invasive carp to new locations. We conducted a short-term telemetry study within two tributaries of the Missouri River to assess Silver Carp distribution and movement patterns associated with season, environmental conditions, and barriers to inform containment and control management actions. We tagged 40 Silver Carp in both the Vermillion River and Big Sioux River near the confluence with the Missouri River with Vemco V16-4H acoustic tags. An array of passive telemetry receivers (n = 5 per river) was used in each tributary below the first impassable barrier to the confluence to monitor the movement and distribution of tagged Silver Carp from May 26, 2021 through October 15, 2021. There were over 1.5 million detections and 3,723 individual daily detections (i.e., individual fish observed on a receiver by day). Silver carp movement patterns generally coincided with discharge, especially a September storm event. Distribution was limited to the first 5 river miles upstream from the Missouri River confluence the entire study period (May-Oct), under low and relatively stable discharge conditions. Silver Carp congregated in the lower reaches (river mile 0-5) of each tributary where deeper, slower velocity water was more abundant during low flow conditions. These results suggest that these lower reaches of tributaries could be targeted for Silver Carp management actions during low flow water conditions.

Hidden Invaders: Invasive Species in Live Bait

Hannah Mulligan1**, Benjamin Schall2, Tanner Davis2, and Dr. Alison Coulter1

1South Dakota State University, Brookings

2South Dakota Game, Fish and Parks, Sioux Falls

Fish species are among the most introduced organisms worldwide, with most introductions occurring by human-mediated events. One method of a human-mediated introduction is through the live bait trade. Juvenile non-native fish can appear similar to many bait species, making it difficult to distinguish between native and non-native fish in bait shops. Recreational anglers releasing unused live bait into waterbodies could inadvertently spread invasive species and cause negative ecological and economic impacts. In the US, fishing regulations in most states prohibit the release and transfer of live bait. However, anglers may still intentionally release unused bait into waterbodies instead of the trash or an appropriate disposal location. As a result, bait introductions could spread non-native species beyond current barriers. Education programs seek to prevent this type of introduction, but an improved understanding of the risk the live bait trade poses for introduction would help refine education campaigns. This poster addresses an initial exploration of the variation in live bait regulations among states in the Missouri River basin. Future research will use eDNA sampling techniques to test for the presence of key invasive species, Bighead Carp and Silver Carp, while also identifying risk factors associated with invasive species presence in the live bait trade. Results will provide a greater understanding of the risks of invasives in the live bait trade and an additional resource for detecting potential invasion sources of Bighead Carp and Silver Carp. Future implementable actions could include refined educational campaigns, increased inspections of bait distributors, or additional live bait regulations following risk factor identification.

Evaluating Size and Age Variation Among Spawning Chinook Salmon in the Nushagak River System

Jack Niedringhaus1* and Alison Coulter1

1South Dakota State University, Brookings

The Nushagak River System supports one of the largest Native Chinook Salmon runs in the world. A tributary river to Bristol Bay, the Nushagak River system receives an annual run of approximately 235,000 Chinook Salmon from early June to late July. The size and age of Chinook Salmon vary greatly among individuals that return to their Native rivers throughout their spawning run. The size and age of a Chinook Salmon can correlate to their success while spawning. Larger-sized females will produce a greater number of eggs while larger-sized males will be more fit to protect the redd, resulting in more productive spawn. The objective of this research was to evaluate variation in the size and age of Chinook Salmon throughout the summer 2021 spawning run in the Nushagak River system. A variety of hook and line techniques were used to gather the samples for this study. The weight and total length were measured, sex was observed, and scales were collected between early June to mid-July from a total of 49 Chinook Salmon. The scales were pressed on acetate slides in the lab and independently aged by two readers with a third resolving disagreement.

Using Telemetry Data to Inform Paddlefish Sampling Efforts in a Missouri River Reservoir

Landon Pierce1, Daniel James1, Cameron Goble2, Mark Fincel2, and Mike Smith2

1U.S. Fish and Wildlife Service, Pierre

2South Dakota Game, Fish and Parks, Ft. Pierre

Lake Sharpe, SD, supported a paddlefish population shortly after impoundment, but harvest quickly declined thereafter. Paddlefish have been stocked into this Missouri River reservoir since 2015 to re-establish the population and potentially support a sport fishery. Stocked individuals are approaching sexual maturity, and population assessment will be needed to evaluate stocking success and sport fishery potential. Currently, however, it is unclear if Paddlefish will congregate in areas that allow efficient sampling because recent assessments have focused on initial (≤ 1 year after release) movement and distribution of translocated adult and hatchery-reared age-0 Paddlefish. To inform population assessment efforts, we evaluated temporal patterns in distribution of 10 translocated adult Paddlefish by summarizing distribution data collected with passive receivers 14 – 40 months after translocation. Areas immediately downstream of Oahe Dam (i.e., Stilling Basin and Diver’s Point) had the highest intensity (i.e., fish per day) of use. The Stilling Basin had relatively high use throughout the year, but use of Diver’s Point was primarily during June – October. Our results suggest that sampling immediately downstream of Oahe Dam likely provides the most effective sampling areas but that site selection may vary seasonally.

Harmful Algal Blooms in Lakes throughout North Dakota

McKenzie Schick1

1North Dakota Department of Environmental Quality, Bismarck

Harmful Algal Blooms (HABs) have become an issue for people that use North Dakota’s waterbodies for recreation and agriculture. NDDEQ spends much of the recreational season sampling blooms to better inform the public about possible health concerns. Samples are taken in waterbodies with suspected microcystin toxins. The lakes that are sampled are chosen by reports from the public. The public’s awareness and willingness to participate in the HABs program is vital to its success. There are several lakes that consistently have HABs issues, so those lakes are sampled regardless of a report. While visiting the suspected bloom the sampler needs to find the bloom. Since blooms are mobile and can be widespread sampling may require the sampler to visit multiple locations on a lake and take multiple samples. The samples taken at a potential cyanobacteria bloom are tested using test strips out in the field and sent into the lab for further analysis. If microcystin concentrations come back at levels that are a cause for health concerns in humans, pets, or livestock, an advisory or warning is issued. HABs have been reported in lakes across the state with the most sampled being in the Southwest.  As the HABs Surveillance Program grows more lakes are being sampled. This gives us more information on the prevalence of the blooms and toxin concentration trends.

Mussel Relocation on the Sheyenne River

Skylar Yarbro1** and Andre DeLorme1

1Valley City State University, Valley City, ND

On the Sheyenne River below the Kathryn Dam laid one of North Dakotas largest mussel bed.  With the Kathryn Dam set to be removed there was concern for the mussel population below the dam. To decrease potential mussel population loss, over the course of four days in October of 2020 the Valley City State University Macroinvertebrate lab organized volunteers to move mussels from this area.  Volunteers were a combination of VCSU students, ND Game and Fish personnel, and US Fish and Wildlife personnel.  An estimated 10,400 mussels were move either to a site about 7 miles upstream of the dam (~7800 mussels) or a site less than a mile downstream (~ 2400 mussels) of the dam.  Of the mussels that were moved, 409 were tagged with Passive Integrated Transponder (PIT) tags to determine the survival rate of the relocated mussels.  These mussels were primarily Three Ridge mussels and Black Sandshell mussels, both of which are a level II Species of concern in North Dakota.  151 of those were moved to the downstream area and 258 of them were moved to the upstream location. A year later during early October of 2021 a group went to relocate the PIT tagged mussels in the upstream site and 85 out of the 258 tagged were located for a recovery rate of 34.5 %.  Four of the located PIT tags were found on dead shells and 81 were live mussels for a mortality of 4.7%.  Although the mortality rate is very low, suggesting a very positive result for our relocation, the recovery rate is disappointing.  Possible reasons for this rate – fall burrowing of mussels, insufficient time to properly survey, and the learning curve in using the equipment for the searchers.  Further surveys are needed to better assess the success of the relocation.