Midwest Fish & Wildlife Conference 2019

AUTHORS: Curtis P. Wagner, Kevin S. Page – Ohio Division of Wildlife

ABSTRACT: Muskellunge fisheries in Ohio are maintained through stocking.  The Ohio Division of Wildlife (ODOW) stocks approximately 20,000 advanced-fingerling (10–12 inches) Muskellunge annually among nine reservoirs (1 fish/acre).  Currently, voluntary angler reports of Muskellunge catches provide managers with information on the locations, numbers, sizes, and harvest of Muskellunge.  However, this voluntary reporting approach potentially misses critical information on population dynamics metrics such as survival, escapement, and the probability of catching a fish.  To provide additional information on which to evaluate Muskellunge population dynamics in Ohio, the ODOW initiated a long-term tagging study.  Starting in 2013, all Muskellunge stocked into four study reservoirs (>43,000) have been implanted with passive integrated transponders (PIT).  Escapement of Muskellunge is monitored using in-stream PIT detection systems stationed within dam spillways.  Anglers report in-reservoir recaptures using handheld PIT tag readers.  To date, more than 850 implanted Muskellunge have been detected or reported. Focusing on the escapement component of the study, we found that escapement of Muskellunge appears to vary seasonally and depend on the type of dam water control structure.  For one reservoir, the probability of escapement was 4 – 36%, annually.  Together, these estimates provide a more comprehensive picture of Muskellunge fisheries in Ohio reservoirs.

AUTHORS: Lydia R. Doerr, Dr. Patrick Forsythe, Dr. Christopher Houghton – University of Wisconsin-Green Bay; Scott Hansen, Wisconsin Department of Natural Resources; Dr. Kevin Pangel, Central Michigan University

ABSTRACT: Much remains unknown regarding the early life history of Lake Whitefish in the Great Lakes despite their ecological and economic importance. The capture of larval Lake Whitefish in four major Green Bay tributaries (Fox, Menominee, Peshtigo, and Oconto Rivers) indicates the re-establishment of potamodromous stocks and suggests that these tributaries contribute to the overall metapopulation. The collection of larvae from the Sturgeon Bay shipping canal and the other reefs throughout Green Bay provides evidence that Lake Whitefish are also spawning in nearshore habitats. The ability to identify natal origin of a specific population is essential to creating effective stock-specific management plans; capable of protecting various sub-population that make up the larger Lake Whitefish metapopulation. Larvae collected during 2017-2018 were used to examine whether otolith microchemistry can accurately determine natal origin of these individuals. Preliminary analyses found significant differences in the ratio of strontium and barium to calcium in riverine and offshore water chemistry for Green Bay and Lake Michigan.  The incorporation of these and other trace elements in larval otoliths allowed for the identification of natal origins of Lake Whitefish sub-populations. Otolith microchemistry proved successful at delineating natal origins at both broader level (i.e. tributary vs. open water) and at the site-specific scale.

AUTHORS: Jeffrey A. Stein, University of Illinois; Solomon R. David, Nicholls State University; Sarah M. King, University of Illinois

ABSTRACT: Gars (Lepisosteidae) and Bowfin (Amiidae), collectively known as holosteans, are among the most ancient fish lineages native to North American waters. Understudied and historically disliked relative to other North American fisheries, many holostean populations have declined due to habitat loss, overfishing, and eradication efforts. Furthermore, knowledge regarding the basic biology and life history of these species is limited. As anglers’ perception of these ancient species begins to transform from “rough fish” to “sport fish,” the need for a better understanding of the ecology and conservation status of holostean populations is fundamental to their effective management. This lightning talk will provide an overview of the Ancient Sport Fishes Project, a collaboration among researcher at the University of Illinois and Nicholls State University that explores the spatial ecology, population dynamics, genetics, and human dimensions of Gars and Bowfin.

AUTHORS: Mario Minder, Mark Pyron, Robert Shields – Ball State University; Emily Arsenault, Greg Matthews – University of Kansas; Bolortsetseg Erdenee, Drexel University

ABSTRACT: Compared the the United States, rivers in Monglolia are very minimally impacted by human development. As part of a larger macrosystems project we focused on the diets of fishes located in both the U.S. and Mongolian Mountain Steppe ecoregions. We analyzed gut contents from fishes collected across multiple sites on each continent to compare diets among species and funtional groups. Using the Manly-Chesson diet selectivity index we compared the contents of our stomachs to results of invertebrate surveys performed concurrently with our fish sampling.The results of this will be used in conjuction with future sampling efforts that will complete in the Summer of 2019 in the Mongolian Grassland.

AUTHORS: Dray D. Carl, Wisconsin Department of Natural Resources; Daniel E. Shoup, Oklahoma State University; Martha E. Mather, Kansas Cooperative Fish and Wildlife Research Unit; Quinton E. Phelps, West Virginia University

ABSTRACT: Regulation changes are frequently used to alter lakes and reservoir fisheries to achieve management goals.  Although regulations are generally thought to be effective, fisheries management is hampered by a lack of published studies evaluating regulation effectiveness.  This is particularly troublesome given examples where regulations did not have their expected result, as the lack of published literature on this topic means there is little guidance as to when regulations will be effective.  Further, the few studies that address the topic typically just compare samples from before and after regulations are applied.  In this traditional before-after approach, many temporal changes (e.g., drought, flood, mean annual temperature, etc.) could drive changes in the fish population over time that would erroneously be attributed to the regulation change.  Use of the BACI (before, after, control, impact) design is a more robust approach that avoids erroneous decisions that might result from traditional before-after analyses.  However, the BACI design is little used, probably because of the perception that it would require more effort than is available to sample additional control lakes.  However, we suggest that some prior planning and creativity can make BACI designs possible with little additional work, especially in situations where standardized sampling is routinely used to monitor other lakes that could serve as control systems.  It is even possible that multi-state projects could be performed using routine monitoring that is already planned to provide control lakes or additional replication in cases where both states use the same standard sampling protocol.  State agencies considering regulation changes have a unique opportunity to significantly improve our understanding of regulation effectiveness if they planned BACI studies to track effects of new regulations through time, benefiting the entire field with information that up to this point has been sorely lacking.

AUTHORS: Stephanie L. Shaw, Greg G. Sass – Wisconsin Department Natural Resources, Office of Applied Science, Escanaba Lake Research Station

ABSTRACT: The Northern Highland Fishery Research Area (NHFRA) includes five lakes in north central Wisconsin that were designated for experimental fisheries research purposes in the 1940s by the Wisconsin Conservation Commission. The five lakes were selected to encompass the diversity of lake types and fish communities present in Wisconsin. The NHFRA has maintained the longest running compulsory creel census in the world (1946-present), has monitored fish community, aquatic ecosystem, and climatic variables through standardized surveys, and has conducted directed research to evaluate unrestricted fisheries (no closed season, bag limits, or length limits), harvest regulations, gear restrictions, and the influences of stocking over time. Key species evaluated in the context of fisheries regulations or stocking have included walleye Sander vitreus, smallmouth bass Micropterus dolomeiu, northern pike Esox lucius, muskellunge Esox masquinongy, and lake trout Salvelinus namaycush. The creel census and standardized fish surveys have afforded valuable information to WDNR biologists regarding angler and fish responses (single-species and fish community) to a given regulation change. We will summarize the history of the Northern Highland Fishery Research Area and discuss several case studies of walleye, muskellunge, and smallmouth bass responses to harvest regulations or the lack thereof that have been directly applied to fisheries management in Wisconsin. By combining long-term creel survey information with standardized fish population surveys, Wisconsin has been able to make sound, science-based decisions to manage its diversity of fishery opportunities and has also been able to rapidly respond to emerging fisheries issues.

AUTHORS: Michael J. Dreslik, Illinois Natural History Survey; John A. Crawford, National Great Rivers Research and Education Center; Sarah J. Baker, Illinois Natural History Survey; Christopher A. Phillips, Illinois Natural History Survey

ABSTRACT: For effective conservation and recovery, an adaptive management framework is often best when paired with monitoring population-level responses. In many species, monitoring abundances over time using traditional capture-mark-recapture (CMR) methods is logistically challenging. N-mixture models are an extension of the occupancy and detection probability framework and can estimate abundances across multiple populations. The models use raw abundance counts taken during surveys, model the distributions of capture frequencies, incorporate density-dependent effects and can provide population estimates when recaptures are too few. When validated with traditional CMR estimates, they can provide robust estimates for multiple populations across the landscape. We chose to determine the effectiveness of an N-mixture modeling approach to generate population size estimates for the Eastern Massasaugas within the Carlyle Lake region in Illinois. Our results will be used to determine regional population trends and provide a foundation to assess the effectiveness of conservation actions.

AUTHORS: Michael J. Mounce, Division of Fisheries, Illinois Department of Natural Resources

ABSTRACT: The Division of Fisheries in the Illinois Department of Natural Resources lists specific protocol in our Manual of Operations for standardized sampling methods for the evaluation of both fish populations and the success of stocked fish. We do not have standardized methods specified for evaluating harvest regulations. Our biologists realize that this would be a valuable tool. The Division of Fisheries does have a standard form for submitting harvest regulations requests/suggestions for review by piers, mid-level managers, and finally approval by the Chief of Fisheries. This form does not include any request or requirements for evaluating the suggested regulation. The AFS book, "Standard Methods for Sampling North American Freshwater Fishes" suggested sampling methods for specific species would be a great foundation if these methods can be employed prior to implementing the harvest regulation. Effectively and adequately collecting data about the "three" rate functions, recruitment, growth, and mortality, is critical. The estimation of angler mortality is a critical component of any harvest regulation proposal. Angler harvest/creel surveys should be the foundation of any harvest regulation proposal and evaluation, as the success of any regulation will only be realized where angling mortality is a/the critical factor in limiting the quality or viability of a fishery. Many state agencies, including the Illinois Department of Natural Resources, are facing staffing and funding shortages for a wide variety of reasons and this affects their ability to critically evaluate the effectiveness of harvest regulations, or propose and implement new sampling protocol. However, the development of methods and tools (supporting software) to appropriately propose and evaluate harvest regulations would be highly valuable asset to fisheries managers, the resources they manage, the agencies and constituents they work for, and ultimately the communities that benefit economically from fisheries with greater stability and improved quality.

AUTHORS: K. Kali Rush, Jacob N. Straub, Matt Palumbo – University of Wisconsin-Stevens Point

ABSTRACT: The Wood Duck (Aix sponsa) is a focal species in the Upper Mississippi River and Great Lakes Region Joint Venture’s (JV) waterfowl habitat conservation strategy. The JV estimates the regional breeding population is 145,000 less than their population objective. In Wisconsin, the wood duck is the second most abundant breeding duck, but their population is declining like other Great Lakes States populations. To better understand population vital rates that could be related to the observed declines in abundance, our objectives were to quantify hen survival and hen and brood habitat use during the breeding season. We captured female wood ducks using decoy and nest box traps from 7 April to 5 July 2017 and 22 April to 20 May 2018, prior to nest initiation, and fitted hens with VHF radio transmitters (ATS 3930, 7g). Hen survival was estimated and compared between breeding status and among predominant habitat type used including emergent wetlands, scrub-shrub, and forested wetlands. We also monitored individuals and nest sites to estimate breeding propensity, clutch size, and nest success. In 2017 and 2018, 43 female wood ducks were captured. We used a known-fate model in program R to model hen survival as a function of breeding status (i.e. attempted nest or did not attempt nest) and habitat types. This approach yielded heretofore unavailable hen and brood survival estimates for breeding wood ducks in the state of Wisconsin to improve our knowledge of how wood duck populations are changing. 

AUTHORS: Drew Holloway, Muncie Sanitary District Bureau of Water Quality; Jason Doll, University of Mt. Olive; Robert Shields, Utah Division of Wildlife Resources

ABSTRACT: The importance of monitoring anthropogenic changes in a lotic system are not limited to chemical water quality monitoring. The addition of biological monitoring allows fish to be used as bioindicators because of their varying tolerance to pollution. For this study we utilized long-term water quality and fish data to evaluate temporal changes brought on by passage of the Clean Water Act (1972). Non-metric Multidimensional Scaling (NMS) was used to describe changes in the fish community and also heavy metal concentrations of the West Fork White River inMuncie, Indiana over the past 33 years. The NMS results for both heavy metals and fish separated into distinct decadal clusters. The shift in fish community data was characterized by a drop in pollution tolerant species and an increase in intolerant species. A decrease in heavy metal concentrations (chromium, zinc, and lead) was also found during this time period. All NMS fish axis had a positive slope indicating an increase in intolerant species as heavy metal concentrations decreased. Our findings indicate that the water quality improvements documented in the West Fork White River have directly impacted its local fish community. 

AUTHORS: Mark J. Fincel, South Dakota Department of Game, Fish and Parks

ABSTRACT: In an effort to improve size structure of Smallmouth Bass Micropterus dolomieu in Lake Sharpe, a large Missouri River impoundment, the South Dakota Department of Game, Fish and Parks instituted two protected slot limits: restricted (305-457 mm) beginning in 2003 and relaxed (355-457 mm) beginning in 2008. We examined the effects of these regulations on Smallmouth Bass harvest and population characteristics and compared creel and population trends of Lake Sharpe Smallmouth Bass to adjacent reservoirs where Smallmouth Bass harvest was not regulated. Prior to the slot limit, the majority of the Smallmouth Bass harvest on Lake Sharpe was from 250-400 mm (PP355 mm, and angler catch of trophy Smallmouth Bass was observed, suggesting an effective regulation. However, a before-after-control-impact (BACI) study design and analysis indicated the slot limit regulation was not likely contributing to the observed increases in Smallmouth Bass size structure. Indeed, similar changes in size structure were observed in abutting Lakes Oahe and Francis Case, suggesting a Missouri River system-wide affect was responsible for observed population changes. Subsequently, the protective slot limit regulation was removed from Lake Sharpe in 2012.

AUTHORS: Dan Traynor, Shawn Sitar – Michigan Department of Natural Resources Marquette Fisheries Research Station; Ji He, Michigan Department of Natural Resources Alpena Fisheries Research Station

ABSTRACT: Lake trout are the dominant piscivore in the upper Great Lakes and are a major focus in fisheries management.  Lake populations underwent catastrophic collapses in the middle of the 20th century but have recovered in Lake Superior due to diligent management actions.  Recently, lake trout recovery has improved in Lake Huron and there are indications that Lake Michigan may be following suit.  Although controls on fishing, sea lamprey suppression, and stocking of hatchery fish were instrumental in lake trout recovery, we pose that dietary flexibility also contributed to its success.  We analyzed the diet of a broad size range of lean and siscowet lake trout from spring and summer gill net surveys conducted in southern Lake Superior and western Lake Huron during 2005-2016.  In addition to categorizing prey items by taxa, we grouped prey items by habitat types to further describe dietary flexibility.  We found that lake trout diet compositions were diverse in both lakes Superior and Huron. Generally, the diet of leans and siscowets in Lake Superior were similar.  We observed ontogenetic diet shifts in both lean and siscowet lake trout with small fish feeding predominantly in the benthos expanding to the pelagic zone as fish grew larger.  Progress in lake trout recovery in Lake Huron coincides with collapses in alewife abundance and declines in Chinook Salmon populations.  We pose that lake trout success in rapidly changing ecosystems is partly due to its high dietary flexibility and declines in Great Lakes Chinook salmon are due to its strong reliance on pelagic prey such as alewife.

AUTHORS: Tristan Tackman (Student); Dr. Ashely Moerke (Professor/Undergraduate Advisor); Jake Larsen (Graduate) – School of Natural Resources and Environment, Lake Superior State University

ABSTRACT: The St. Marys River is the only outflow of Lake Superior and feeds both Lake Michigan and Lake Huron. The river itself rears a majority of these lakes’ sports fishes by providing ample spawning grounds; these young fish rely on small macroinvertebrates for most of their growth in early years. The objective of this study was to quantify and compare the supply of drifting invertebrates from the main rapids and the hydropower canal in an effort to understand key food sources available for fishes in the river.  To do so, two larval drift nets were set overnight in the rapids and canal to collect drifting invertebrates during the months of May and June 2016.  For each date biomass was calculated asash free dry weight and density was calculated as number of invertebrates per 100m³. Densities were the highest for Hydropsychidae and Mysidae at both sites, andcomprised 18% (the remanding 82% being non-dominant taxa) and 9.5% in the rapids and 26.7% and 8.9% in the canal site. Although Mysidaedensities were higher than other taxa, Hydropsychidae contributed more biomass to the system in both sites during May and June of 2016. Additionally, total drift densities were 2.4 times higher in the canal site than the rapids, suggesting that the canal is a better source of invertebrates to the St. Marys River. The canal is likely drawing water from more offshore areas in Lake Superior, which may explain the higher numbers of drifting Mysids in the canal site compared to the rapids.

AUTHORS: Cameron Goble, Hilary Meyer, Mark Fincel, Chelsey Pasbrig – South Dakota Game, Fish and Parks; Dylan Turner, U.S. Fish and Wildlife Service

ABSTRACT: Acoustic telemetry is often used to document fish behavior including survival, movement and habitat use. We used information from a combination of a passive acoustic receiver arrays, active tracking, and fisheries assessments to evaluate the potential to reestablish historic Paddlefish (Polyodon spathula) and Shovelnose Sturgeon (Scaphirhynchus platorynchus) fisheries in Lake Sharpe, a Missouri River impoundment in central South Dakota.  In 2015, South Dakota Game, Fish and Parks and U.S. Fish and Wildlife Service began stocking paddlefish into Lake Sharpe to reestablish a sport fishery last open in 1964. We used acoustic telemetry to document movement patterns and habitat use of translocated adult paddlefish (n =40) and determine post-stocking dispersal and survival of age-0 paddlefish (n = 50). We used information from seasonal movement patterns of translocated adult paddlefish to assess the feasibility of creating a shore based recreational fishery.  Post-stocking dispersal rates of age-0 paddlefish was used to prioritize future stocking locations. We also used acoustic telemetry to document movement and population dynamics (recruitment, growth, mortality) of a remnant Shovelnose Sturgeon (n = 50) population in Lake Sharpe. A combination of acoustic telemetry and a mark-recapture study will provide information on basic population demographics of Shovelnose Sturgeon in Lake Sharpe.  We will incorporate Shovelnose Sturgeon population dynamics into modeling software (e.g. FAMS) to set appropriate harvest regulations for Shovelnose Sturgeon.  Here, we provide a case study of using acoustic telemetry paired with traditional fisheries assessment tools as important components of fisheries management decision making in South Dakota.

AUTHORS: Cory Becher, The Ohio State University, Aquatic Ecology Laboratory, EEOB; Stephen M. Tyszko, Ohio Department of Natural Resources-Division of Wildlife; Dr. John Olesik, The Ohio State University, Trace Elements Research Laboratory; Dr. Stuart A Ludsin, The Ohio State University, Aquatic Ecology Laboratory, EEOB

ABSTRACT: Stocking is a key management tool used to establish or enhance fisheries in reservoir ecosystems. Quantifying the contribution that stocked individuals make to the fishable population should be an essential component of any stocking program. However, such post-stocking assessment is oftentimes neglected, likely owing to difficulties associated with using conventional (i.e., artificial) tags to discern stocked individuals from wild-produced ones. To help the Ohio Division of Wildlife (DOW) better assess its Channel Catfish (Ictalurus punctatus) reservoir stocking program, we have been evaluating the use of otolith microchemistry—quantified using laser-ablation plasma-mass spectrometry—as a natural tag to discriminate between stocked and wild-produced individuals. Herein, we first present results from predictive quadratic discriminate function (QDF) models that were developed for three reservoirs, which we used to differentiate wild-produced individuals from hatchery-reared individuals. These models were built using known signatures from the hatchery and reservoirs. We used core and edge chemistry of hatchery-reared broodstock and juveniles, as well as the recent edge chemistry of individuals captured in the three reservoirs. Afterwards, we present findings from our predictive analyses, which used the QDF models to classify reservoir individuals unknown core signatures as either stocked (hatchery origin) or wild-produced. Our preliminary findings indicate that otolith microchemistry can be used as a tool to identify the natal origin of wild-caught fish in our study reservoirs, with stocked fish comprising less than half of the population at large in each reservoir. We ultimately discuss the value of this approach for helping management agencies such as the Ohio DOW assess the effectiveness of their channel catfish stocking programs.

AUTHORS: Christopher Vandergoot, US Geological Survey; Matthew Faust*, Ohio Department of Natural Resources; Jason Robinson, New York State Department of Environmental Conservation; Andy Cook, Ontario Ministry of Natural Resources and Forestry; Tom MacDougall, Ontario Ministry of Natural Resources and Forestry; Charles Krueger, Michigan State University

ABSTRACT: Walleye support important commercial and recreational fisheries throughout Lake Erie.  To manage this fishery sustainably, a thorough understanding of the underlying biological and ecological processes regulating population dynamics is essential.  Recently, numerous acoustic telemetry studies have been undertaken to address key management uncertainties associated with movement patterns, spawning ecology and phenology, stock contributions, habitat use, and population dynamics. While these studies have resulted in an unprecedented amount of information, challenges ranging from determining best tagging practices, maintaining receiver networks, managing and analyzing large datasets, and communicating research findings to managers and constituents have occurred along the way.  This presentation will provide an overview of past and current Lake Erie walleye acoustic telemetry projects and summarize management uncertainties addressed to date.  Additionally, how results from completed and ongoing studies could be incorporated into current stock assessment practices will be presented.  Lastly, we’ll discuss how biologists and researchers communicate these scientific findings to a diversity of audiences, from fishery managers to resource users.

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: Ben C. Neely, Jeff D. Koch, Connor J. Chance-Ossowski – Kansas Department of Wildlife, Parks, and Tourism

ABSTRACT: Bluegill Lepomis macrochirus contribute to unique fisheries in Kansas where they fill many niches. One niche that has been gaining recent attention from anglers is pursuit of large individuals. These efforts typically occur during the Bluegill spawn in May and June when anglers can visually target nest-guarding fish. A combination of being visually evident and aggressively defending nests makes Bluegill especially susceptible to angler harvest during this time. There is concern that harvest of nest-tending Bluegill may remove the fastest growing individuals from the population and ultimately results in populations that do not support quality Bluegill fisheries. To this end, Bluegill were sampled from 14 Kansas impoundments with both fall electrofishing at random shoreline locations and spring angling for nest-tending individuals in 2017 and 2018. Total length was recorded from all captured individuals and otoliths were collected from up to five individuals per centimeter group for age and growth estimation. In all impoundments, length distribution of sampled bluegill differed between gears with angled fish shifted toward larger individuals. Similarly, angled fish exhibited more rapid growth than randomly sampled individuals in some populations. These results highlight the vulnerability of the fastest growing individuals in bluegill populations to angler harvest while preparing and guarding spawning sites. Further, these results suggest that instituting some level of protection to nest-guarding Bluegill might result in increased size structure and promote development and maintenance of quality Bluegill fisheries.

AUTHORS: Edward. D. Davis, Western Illinois University; Tim C. Swearingen, Western Illinois University; Robert W. Klaver, U.S. Geological Survey; Christopher N. Jacques, Western Illinois University

ABSTRACT: Increased understanding of mortality of bobcats (Lynx rufus) is a prerequisite to successful management programs, particularly as it relates to population dynamics and the role of population models in adaptive species management. Survival and cause-specific mortality of bobcats have been well documented in predominantly forested landscapes, but limited information has been collected in agriculturally-dominated Midwestern landscapes. Thus, our objective was to evaluate survival and cause-specific mortality rates of bobcats across agriculturally dominated landscapes of west-central Illinois. We captured and radio-collared 38 (20 males, 18 females) bobcats from January 2016 to September 2018. We used known fate models with the logit link function in Program MARK to estimate annual survival of bobcats, which accommodated staggered entry and exit times of radiocollared bobcats during our analysis interval. Because mortality events were limited, covariate modeling was not conducted. Nevertheless, we constructed a survival model in which survival was constant (S{_constant}) between years and across sexes. We documented 11 deaths during our study; vehicle collisions was the leading cause of mortality and accounted for 5 (45%) mortality events. We attributed remaining deaths to harvest (n = 3; [1 legal, 1 illegal, 1 incidental harvest]), unknown (n = 1), other (n = 1), and capture-related factors (n = 1); we censored capture-related deaths from analyses. The estimated annual survival rate using model S{_constant} was 0.74 (95% CI = 0.55–0.87). Bobcat survival monitoring is ongoing through 2019 and will evaluate potential effects of intrinsic and habitat variables on seasonal and annual survival rates.

AUTHORS: Matthew Palumbo, University of Wisconsin-Stevens Point; Jacob Straub, University of Wisconsin-Stevens Point, David Luukkonen, Michigan State University; John Coluccy, Ducks Unlimited

ABSTRACT: Abstract: Applied scientific research has been an underpinning of sound waterfowl and wetland conservation for decades. The Lower Great Lakes (LGL), especially wetland and adjacent upland habitats near Lakes Erie, St. Clair, and Ontario, were historically and remain a critical region for waterfowl of the Atlantic and Mississippi Flyways. In fact, hundreds of thousands of waterfowl use this landscape as their primary breeding location and millions use the resources of the region during migration between breeding and wintering areas. Waterfowl managers and researchers in the LGL have strong partnerships and have largely focused efforts in this region on studies that improve understanding of the overall ecology of the species and how management actions can influence these birds. Specifically, the LGL have been the home to seminal studies on waterfowl bioenergetic modeling during spring migration, habitat use and movement for key focal species (e.g., mallards), monitoring and evaluation of diving sea duck distributions on the Great Lakes, studying the potential limiting factors for Great Lakes mallard populations, and influence of weather, wetland availability, and mallard abundance on productivity of Great Lakes mallards. Importantly, these studies have critical linkages to management which have serviced wetlands conservation. Our objective is to synthesize recent research that has improved our understanding of waterfowl ecology and habitat management in the region. Additionally, we will identify future research needs and information gaps to expand waterfowl conservation in the LGL.

AUTHORS: Hae H. Kim, Quinton E. Phelps – West Virginia University Division of Forestry and Natural Resources; David Weyers, Sara J. Tripp – Missouri Department of Conservation Big Rivers Field Station.

ABSTRACT: Survival during early life history and recruitment adult structure population demographics. Numerous studies have demonstrated that riverine fishes are prone to variable early life survival and recruitment. High abundance of Silver Carp Hypophthalmichthys molitrix in the upper Mississippi River basin suggests great spawning and recruitment success. Previous studies have largely focused on characterizing adult Silver Carp populations. However, early life history has not been evaluated. Thus, we examined relative abundance, growth rates, hatch timing, and mortality of age-0 Silver Carp. We used data collected in mini-fyke nets by the Long Term Resource Monitoring element in three river upper Mississippi River reaches. A total of 154,092 age-0 Silver Carp were captured, ranging from 7.5-170 mm. Catch per unit effort ranged from 0-107 fish/net with an overall average of 11.86 (0.4) fish/net. Growth rates ranged from 0.74 – 1.81 mm/day with a total mean growth rate of 1.25 mm/d (0.03) mm/day. Daily mortality (z) ranged from 0.74-0.94 and averaged 0.832 (0.09). Silver Carp hatched within a 115-day window between 22 May and 15 September, with hatch peaking between 21 June and 19 July. Baseline demographic knowledge will aid managers control and limit Asian Carp spread throughout the Mississippi River Basin.

AUTHORS: Katherine Wright, Crystal Robertson, Paul Yannuzzi, Shannon Ritchie, Andrew Lentini, Bob Johnson, Rick Vos – Adopt-A-Pond Wetland Conservation Programme, Toronto Zoo

ABSTRACT: A head-start program for Blanding’s turtles (Emydoidea blandingii) was launched in 2012 by Toronto Zoo’s Adopt-A-Pond Wetland Conservation Programme and partners in an effort to recover a local population in the Rouge National Urban Park (RNUP). As per a Population Viability Analysis (PVA) in 2013, reaching a self-sustaining population required raising 50 turtles per year for two years each at a 60 female: 40 male ratio over 20 years. The head-start turtles are incubated and raised in a protected zoo environment, which includes a month in outdoor enclosures to acclimate to natural conditions. Then, a soft-release enclosure is used with half of the cohort for in-situ to acclimate to their new wetland prior to release into the wild, while a hard-release method is used for the other half (no in-situ acclimation). The release site is known habitat for Blanding’s turtles and is in close proximity to travel corridors, though many head-start turtles remain in the wetland area in which they were released. No significant difference has been observed between home ranges of soft- and hard-release turtles. The number of turtles released per cohort has increased each year (2014: 10, 2015: 21, 2016: 36, 2017: 49, and 2018: 49), as have cumulative survival rates (2018 data is still being incorporated). Survival, movement, and habitat use patterns are monitored by radio tracking a subset of turtles from each release cohort, which occurs three times per week from May-August and once per month from December-April. The number of tracked turtles from each cohort changes yearly as more turtles are released. In 2018, a total of 48 turtles were tracked out of the 165 that have been released to date. This long-term project will use adaptive management to improve husbandry, field research, habitat restoration and community outreach as the project progresses.

AUTHORS: K.B. Wood, Cassi J. Moody-Carpenter, Robert E. Colombo – Eastern Illinois University

ABSTRACT: Highly variable discharge experienced by the lower Wabash River due to a more natural hydrology pattern overlaps with Channel Catfish (Ictalurus punctatus) reproduction period; this leads to variable conditions for age-0 fish to develop upon hatching. There ubiquitous pattern of cryptic information published about age-0 Channel Catfish, and any insight would be advantageous to multiple facets in Channel Catfish life history. While a male will spawn multiple times through the year, reproduction is dictated by the females, only becoming gravid once annually; females becoming gravid at separate times leads to there being non-coeval cohorts. In their larval stages, endogenous feeding promotes a constant growth rate, but switching to exogenous feeding and entering the juvenile stages leads to growth dependent on the environmental conditions. We observed stable reproduction in varying conditions over four years of sampling (p > .05). Peak abundance in August signifies a peak in the aggregation of cohorts. Past surveys have shown there are at least five cohorts of age-0 Channel Catfish throughout the spawning season in the Wabash River; investigations into growth patterns of these cohorts by estimating daily growth from the otoliths can offer insight into which cohorts may best be utilizing their available resources. Variations in growth patterns could come from present conditions, normal seasonal variation, or a combination of both. Results from this study could aid in creating a recruitment index for Channel Catfish in this exploited lotic system. 

AUTHORS: Tim Lyons, University of Nebraska-Lincoln; T.J. Benson, Illinois Natural History Survey; Wade Louis, Illinois Department of Natural Resources; Mike Ward, University of Illinois at Urbana-Champaign; Richard Warner, National Great Rivers Research & Education Center

ABSTRACT: In agriculturally dominated landscapes, the habitat provided by public and private lands is critical for the conservation and management for non-game as well as game species, such as ring-necked pheasants. Management of these areas to increase pheasant populations has focused on increasing field size, the amount of grassland cover in the landscape, or managing vegetation composition within fields, to improve success during the nesting or brood-rearing stages, or the survival of breeding adults. How these actions will impact overall population growth or which stages or habitat features should be prioritized for management is not always clear. We studied how habitat conditions at the field-and landscape-scale influenced the demography of ring-necked pheasants on public and private grasslands in Illinois. Between 2013-2016, we used radio telemetry to track > 200 ring-necked pheasants and quantified the relationship between habitat features at multiple spatial scales, nest success, chick survival, and adult survival. We then used a simulation study to understand how changes to habitat features important to a particular stage ultimately affected population growth. We also examined how predator identity influenced the relationship between adult survival and habitat conditions. We found that several habitat features had contrasting effects among multiple stages and ultimately restricted population growth when management focused on maximizing performance during one stage. Our results also indicate that raptors may be a more important predator of pheasants than is generally recognized, but the risk of predation can be reduced by the management of vegetation within fields. Collectively our work highlights the importance of full life-cycle studies of demography for the effective management of wildlife and suggests that smaller fields, often overlooked in traditional conservation schemes, can play a role in pheasant management when coupled with appropriate management of vegetation within fields.

AUTHORS: Rebekah L. Anderson, Nathan J. Lederman – Aquatic Nuisance Species Program, Illinois Department of Natural Resources; Cory A. Anderson, U.S. Fish and Wildlife Service; Jason A. DeBoer, Illinois River Biological Station, Illinois Natural History Survey.

ABSTRACT: Substantial research attests to the injurious impacts invasive silver carp (Hypophthalmichthys molotrix) have on Midwestern U.S. river systems. Particularly, the dietary overlap between silver carp and native planktivores has resulted in declined condition and abundance of these species in areas where silver carp dominate the community (i.e., the lower Illinois River). However, additional research demonstrates silver carp may benefit native non-planktivorous fishes because of the carp’s ability to produce young at a large scale providing an abundant prey source for native piscivores, and their nutrient rich fecal pellets may enrich benthic forage quality for native benthivores. Potential positive effects of silver carp for native fishes are not fully understood, and research is limited in natural systems. Here we determine whether silver carp benefit non-planktivorous native fishes in the lower Illinois River (i.e., Peoria, LaGrange, and Alton pools) by examining native piscivore and benthivore body condition over time utilizing two standardized long-term data programs. We found a significant positive relationship between silver carp abundance and native benthivore body condition. Moreover, visual trends indicate increased body condition during and immediately after strong silver carp year classes (2008 & 2014) for both native piscivores and benthivores. Therefore density-dependent effects may exist where juvenile silver carp populations and benthic nutrient levels must reach a threshold before they are exploitable (i.e., beneficial) resources. We suggest more years of data that incorporate strong silver carp year classes may be needed to clarify potential positive effects of silver carp for native non-planktivorous fishes.

AUTHORS: Tyler Ham, Indiana Department of Natural Resources; Dr. Quinton Phelps, West Virginia University

ABSTRACT: Population dynamics are important to consider when managing recreational fisheries. Population dynamics interact with effects of harvest to create fluctuations that may need ameliorated through regulation. Black Crappie (Pomoxis nigromaculatus)are a popular sport fish in the United States that anglers spend time and money pursuing on a yearly basis. Despite their importance, limited information exists on Mississippi River Black Crappie. Therefore, the goal of this study was to evaluate the population dynamics of Black Crappie in Pools 4, 8, and 13 of the Upper Mississippi River. The potential for growth overfishing was evaluated through the use of yield-per-recruit modelsand based on historic harvest rates and habitat modifications within these pools. Overall, 201 crappie were collected from Pool 4, 215 from Pool 8, and 130 from Pool 13 during the summer and fall of 2016. All fish were weighed, measured, and aged via sagittal otoliths. We simulated exploitation for six different length limits. We found that growth overfishing did not occur until exploitation rates exceeded 50% for fish less than or equal to 152 mm. These results suggest that Black Crappie populations in Pools 4, 8, and 13 are not at risk of growth overfishing, but continued monitoring is warranted due to the potential influence of extrinsic factors like climate change, eutrophication, and vegetation shifts.

AUTHORS: Michael Lowe, Christopher Holbrook – USGS, Hammond Bay Biological Station; Darryl Hondorp, USGS Great Lakes Science Center; Aaron Jubar, USFWS Ludington Biological Station; Jessica Barber, USFWS Marquette Biological Station; Kevin Tallon, DFO Canada Sea Lamprey Control Centre

ABSTRACT: Despite continued monitoring and control efforts, the invasive Sea Lamprey (Petromyzon marinus) population in Lake Erie during 2009 was the highest in the time series and has since remained above target levels set by the Great Lakes Fishery Commission (GLFC).  It was hypothesized that Sea Lamprey production in the St. Clair and Detroit River system (SCDRS), which had undergone extensive restoration in recent years and was historically excluded from control efforts, has been under-estimated.  We present the results of a 2014 pilot study (n = 27 fish) and a larger study spanning 2016 (n = 125 fish) and 2017 (n = 125 fish) that used acoustic-tagged adult sea lamprey to identify potential spawning areas in the SCDRS.  In doing so, we introduce a new statistical method for summarizing and analyzing multidimensional fish movement data.  Our analysis of the 2014 pilot study data is congruent with a previous analysis of those same data using a more complex multinomial process model.  Both analyses show similar detection probabilities and behavioral aspects of sea lamprey movements, and ultimately reach the same conclusion: most Sea Lamprey spawning occurred in the lower half of the St. Clair River.  The 2016 and 2017 study, which had more fish and a more extensive array of acoustic receivers, further reduced the potential spawning area down to the middle St. Clair River between the mouth of the Belle River and Stag Island. The combined results of these studies address several needs identified by the GLFC and are expected to inform and guide alternative assessment and control strategies in the SCDRS.

AUTHORS: Kevin R. Keretz; Richard T. Kraus, Joseph Schmitt – US Geological Survey

ABSTRACT: Ecological and societal impacts of dreissenid mussels (Dreissena spp.) on Great Lakes ecosystems are well documented, and a better understanding of the mechanisms that cause variation in mussel abundance is needed.  An outstanding question is how much mussel biomass is consumed by predation. To date, attention has mainly been focused on invasive Round Goby (genus species) predation of mussels.  We note that the biomass of native mussel consumers, such as Freshwater Drum (Aplodinotus grunniens), may exceed Round Goby biomass by an order of magnitude in some areas.  Thus, the role of predation on mussel population dynamics may be greater than is currently assumed.  A significant difficulty for investigating mussel consumption by native predators is that mussels in stomachs are often a macerated mix of crushed shell and flesh. This prevents counting and measurement of individual prey items as is often performed in diet studies.  Here, we develop an analysis to convert the crushed shell and flesh mixture found in diets of Freshwater Drum to a simple dry weight of mussel flesh.  We then estimate daily ration as a first step in understanding the impact of Freshwater Drum on mussel populations in Lake Erie.  Our results support evaluation of proposed mussel control methods by improving our knowledge of ecological mechanisms that influence mussel abundance.  

AUTHORS: Craig Jansen, Indiana Department of Natural Resources

ABSTRACT: The Wabash River sustains one of the few remaining commercial fisheries for Shovelnose Sturgeon (SNSG). Since a statewide minimum length limit (25 inches eye-to-fork) was implemented in 2007, there have been concerns that regulations are not offering sufficient protection for the population, specifically mature females. SNSG have been sampled throughout the Wabash River from 2005 to 2018. General demographic data was collected from all fish (length, weight, pectoral fin ray) and sex was identified if possible. All fish were tagged with a unique Floy tag. Linear regressions were used to identify trends in annual mean length of the entire sampled population and confirmed mature females. Average length of SNSG exhibited a general decreasing trend, peaking at 27.1 inches in 2007 and decreasing to 25.5 by 2017. The mean size of confirmed females decreased more dramatically from 28.4 inches in 2009 to 25.9 inches in 2018. Days at-large was calculated for recaptured fish, and individuals were grouped based on size at original tagging. Recaptured fish exhibited a strong homing behavior as most were captured less than 5 miles from the original tagging site. Several SNSG have been recaptured 10 to 13 years after tagging and exhibit little to no growth. Once maturity is reached growth becomes negligible, and individual fish do not follow a typical population growth curve. Results suggest regulations have allowed overharvest, and more specifically, the removal of fast-growing and large females from the population. Based on the unique life-history and lucrative market value of SNSG, traditional fisheries management tools, such as minimum length limits, may not adequately protect the population from overharvest. More restrictive regulations are needed to ensure the Wabash River SNSG do not collapse like other sturgeon populations throughout the world.

AUTHORS: Tim Lyons, Larkin Powell – University of Nebraska-Lincoln; Mark Vrtiska, Nebraska Game and Parks Commission

ABSTRACT: Bird banding is a basic but important form of population monitoring that is vital to waterfowl management in the U.S. Most often, the data derived from state and federal banding programs are used to estimate survival and harvest rates and distributions across broad geographic regions, but they can also be used to estimate abundance at more local scales. However, absent or limited population surveys, banding efforts, or recoveries, from neighboring states or provinces complicates efforts, leading to ad hoc approaches to deal with these problems during analysis. Here, we use banding and recovery data of Canada geese in Nebraska 2006-2017 to assess the effects of changing harvest regulations on Canada goose demography and estimate abundance. We demonstrate a modified harvest derivation analysis and Lincoln-Peterson estimator to address pitfalls common to these approaches when estimating abundance. Finally, we discuss Jolly-Seber models as an alternative approach to estimating demographic parameters and abundance that circumvents the need for banding or population monitoring programs out-of-state and provides greater detail about the mechanisms responsible for population changes.

AUTHORS: Sabina Berry, Jim Lamer – Western Illinois University; Jason DeBoer, Andrya Whitten – Illinois Natural History Survey; Rob Colombo, Cassi Carpenter – Eastern Illinois University; Neil Rude, Greg Whitledge – Southern Illinois University Carbondale; Ben Lubinski, Jerrod Parker – Illinois Natural History Survey

ABSTRACT: Channel catfish (Ictalurus punctatus) and Freshwater drum (Aplodinotus grunniens) are two prominent North American sportfishes occupying a similar ecological niche in many river systems. Comparison of historically validated ageing structures and length frequency data can reveal dynamics of fish populations, including their recruitment, mortality, and individual growth patterns. In addition, tracking years of strong and weak growth through biochronological inference can increase understanding of the biotic and abiotic factors affecting individual reaches and rivers. This collaborative project covers reaches of six major rivers spanning Illinois, including the Wabash, Ohio, Illinois, Kankakee, Iroquois, Pools 16, 19, 20, 21, and 25 of the upper Mississippi River, as well as a small section of the lower Mississippi River. All fish were caught in 2017 and 2018 using DC electrofishing gear as part of a long term survey submitted annually to the Illinois Department of Natural Resources. Preliminary results from 2017 revealed weak year classes in all reaches for drum from 2010 to 2014, but stronger classes in the following years. Catfish showed weak years before 2011 and after 2014, but stronger years in between. Drum had faster growth rates in the Ohio and Mississippi reaches and slower growth in the Illinois and Wabash, whereas the catfish initially had faster growth rates only in the Ohio River. Mortality rates were highest for drum in the upper Mississippi River in pools 16 & 19, but lowest in the Ohio River. Catfish mortality rates were low throughout all reaches. Incorporating chronology factors as well as the data collected in 2018 may reveal additional trends and the larger dataset will allow us to further compare pools and reaches within each river. Understanding population dynamics and growth chronology of two common predatory fish spanning Illinois waterways is important for creating potential management strategies and determining their initial necessity.