Midwest Fish & Wildlife Conference 2016

AUTHORS: Chance Kirkeeng*, South Dakota State University, Department of Natural Resource Management; Jason Breeggemann*, South Dakota State University, Department of Natural Resource Management; Brian Graeb, South Dakota State University, Department of Natural Resource Management; Katie Bertrand, South Dakota State University, Department of Natural Resource Management; Troy Grovenburg, South Dakota State University, Department of Natural Resource Management; Bob Lusk, Pond Boss Magazine

ABSTRACT: Reservoir aging and the resulting loss of structural habitat can limit productivity, such as growth rates, of fishes such as largemouth bass in North America. Habitat enhancement using artificial structure could provide the necessary resources to more efficiently transfer energy to largemouth bass thereby increasing population growth rate and reducing home range size. We evaluated the effects of habitat enhancement on largemouth bass in a 60-year-old reservoir. We used radio telemetry to quantify annual and seasonal home range sizes, habitat use, and daily movement of largemouth bass before and after a large-scale artificial habitat addition (i.e., artificial habitat was added to cover approximately 10% of the shoreline area). Prior to the habitat addition, home ranges during the growing season averaged nearly 8 hectares with a maximum of 25 hectares and annual home ranges averaged 9 hectares with a maximum of 28 hectares. Additionally, daily movement rates were very high with some largemouth bass moving as far as 2.25 km in 24 hours. Our results one year post-enhancement showed that daily activity decreased, growth rates increased, and largemouth bass selected for artificial habitat over all other available habitat in the lake. Home range sizes remained similar to the pre-enhancement period. Our results indicated that largemouth bass quickly responded to habitat restoration, but that more habitat may be needed to affect seasonal home ranges. Artificial habitat can be used in aging reservoirs to enhance available habitat.

AUTHORS: Joseph D. Conroy, Ohio Department of Natural Resources; Richard D. Zweifel, Ohio Department of Natural Resources

ABSTRACT: Many factors affect annual success of stocked Sander spp. (both walleye Sander vitreus and saugeye, Sander vitreus ♀ × Sauger S. canadensis ♂). In Ohio, Sander spp. have traditionally been stocked as fingerlings (about 6-week old, 25-mm total length juveniles) but a research project in three tributary reservoirs showed that fry (6-day old, 7-mm) successfully produced cohorts of comparable strength to fingerling stocking when densities of crustacean zooplankton were sufficient. Here we expand this previous research to additional tributary reservoirs (n = 7) and two additional reservoir types (canal, n = 2; upground, n = 11) during the period 2011–2015. We determined zooplankton density and community composition at the time of fry stocking and one week post-stocking. We then directly compared fry stocking success (defined as fall age-0 catch per hour of standardized electrofishing) with zooplankton densities (#/L) concurrent to stocking and used multivariate statistical methods to explore how stocking success related to crustacean zooplankton community composition. Stocking success varied from 0 to nearly 1,000 age-0 Sander spp./ha while crustacean zooplankton densities ranged 72–3,601 zooplankters/L. Although fry stocking success and zooplankton density were not directly correlated, stronger year classes often corresponded with crustacean zooplankton communities composed of mostly calanoid copepods and cladocerans. Consequently, knowing patterns of zooplankton community composition may better identify reservoirs in which fry-stocked Sander spp. do well.

AUTHORS: Christopher Schwinghamer*, Southeast Missouri State University; Sara Tripp, Missouri Department of Conservation; Quinton Phelps; Missouri Department of Conservation and Southeast Missouri State University

ABSTRACT: Creating reservoirs on large rivers drastically alters habitat utilized by the species that inhabit those areas. Large reservoirs transform lotic habitat into lentic habitat, flooding historic spawning habitat and blocking spawning migrations resulting in risks to species that use these habitats. One such species is the paddlefish Polyodon spathula, which are a popular sport fish in Missouri. Demand from recreational anglers has created a need to maintain stability in paddlefish populations across Missouri. Sustainable populations in Missouri’s reservoirs have been maintained through annual stocking, as successful reproduction has never been documented in these systems. As such, our objectives were to locate spawning aggregations and collect eggs or larvae near these aggregations. To accomplish this, paddlefish were captured using gill nets and 100 reproductive adults were implanted with ultrasonic transmitters. Tracking these individuals allowed us to locate spawning aggregations, determine movement patterns, and analyze environmental conditions coincident with paddlefish migrations. Embryo and larval sampling at the sites of these aggregations produced evidence of natural reproduction and provided a known spawning location for paddlefish in Truman Reservoir and its tributaries. These results will allow management officials to assess stocking protocols and help to ensure sustainable populations in reservoir ecosystems.

AUTHORS: Chris G. French*, Ohio Department of Natural Resources; Joseph D. Conroy, Ohio Department of Natural Resources; Richard D. Zweifel, Ohio Department of Natural Resources

ABSTRACT: Forage fish populations play an important role in the success of many Midwestern reservoir sportfisheries. Variations in forage fish abundance are directly linked to reservoir productivity, which fluctuates temporally (i.e., between years) and spatially (i.e., between reservoirs). To better understand the potential for successful sportfish stocking and recruitment, the Ohio Division of Wildlife regularly estimates forage fish abundance and productivity of managed reservoirs. While each managed reservoir is routinely sampled at least once every 3 years, more intensive statewide assessments have also occurred, resulting in a robust dataset that provides statewide measures of forage fish abundance and productivity. Here, we compare results from 2006–2007 and 2012–2014 assessments for a diverse group of reservoirs. During summer (July–August) forage fish abundance was estimated with mobile hydroacoustic surveys, and productivity was estimated using Secchi transparency, total phosphorus concentration, and chlorophyll a concentration. Overall, forage fish abundance increased with increasing reservoir productivity, with similar relationships in both the 2006–2007 and 2012–2014 assessments. However, forage fish abundances and productivity measures differed between reservoirs and years, resulting in complex trends. Our assessments suggest that reservoir productivity primarily shapes forage fish population dynamics in Ohio reservoirs. Understanding changes in productivity both temporally and spatially may help guide reservoir sportfish management.

AUTHORS: Bryan Kinter*, Ohio Department of Natural Resources

ABSTRACT: Due to flat topography, most reservoirs in northwestern Ohio are upground reservoirs, which are built above the ground and filled by pumping water from a nearby river. These reservoirs have nearly uniform depth and lack littoral habitat. Walleye Sander vitreus and saugeye S. vitreus ♀ × S. canadensis ♂ are two sportfish stocked in Ohio’s upground reservoirs. Some reservoirs receive saugeye and some receive walleye, but none currently receive both. If, despite the lack of littoral habitat, saugeye remain closer to shore than walleye in these systems and thus are more available to shoreline anglers, fishing opportunities for shoreline and boat anglers could be maximized by stocking both Sander spp. into the same reservoir. To explore this question, we implanted acoustic transmitters into 15 walleye and 15 saugeye and released the fish into Findlay Reservoir #1, an upground reservoir in northwestern Ohio. Tagged fish were tracked continuously during March 2013–December 2014 with a Vemco VR2W Positioning System. The proportion of total positions within casting distance (defined as less than 25 meters from shore) was estimated by a Bayesian hierarchical modeling approach using species, season, and diel period (day, night, crepuscular) as explanatory variables. Saugeye were more frequently within casting distance of shore than walleye, especially during summer and autumn. These results indicate that stocking both saugeye and walleye may maximize opportunities for shoreline and boat anglers in upground reservoirs. However, saugeye and walleye showed considerable variation with both season and period of day.

AUTHORS: Geoffrey B. Steinhart*, Ohio Department of Natural Resources; Joseph D. Conroy, Ohio Department of Natural Resources; Stuart A. Ludsin, Ohio State University, Aquatic Ecology Laboratory; Richard D. Zweifel, Ohio Department of Natural Resources

ABSTRACT: Many Ohio reservoirs experience seasonal reductions in quality and quantity of fish habitat due to high temperatures and hypoxia. In October 2011, > 13,500 yearling (about 285-mm total length) blue catfish Ictalurus furcatus were stocked into Hoover Reservoir (central Ohio) to diversify angling opportunities and take advantage of excess prey fish by introducing an open water predator tolerant of warmer temperatures and lower dissolved oxygen than many other sport fish. To quantify seasonal habitat use of these newly-stocked predators, acoustic transmitters (Vemco V9L) were surgically implanted in 50 catfish prior to stocking. Approximately biweekly mobile surveys (VR100) were used to determine catfish habitat use from October 2011–November 2012. To compare available habitats with the occupied habitats, a growth rate potential (GRP) model was created to provide spatially-explicit growth predictions throughout the reservoir based on water temperature, dissolved oxygen, and prey abundance. Catfish were primarily located in upstream end of Hoover Reservoir from stocking until January when some catfish started to move toward the lower basin. During spring and summer, when hypoxia dominated deeper waters, catfish were located mostly in the middle and upstream areas where hypoxia was not as great. In fall, after turnover reduced the extent of hypoxia, most fish were found in the middle and lower end. Catfish appeared to select areas with moderate GRP: avoiding areas with low oxygen (which reduces GRP) but not necessarily selecting areas with the highest prey abundance. Overall high prey abundance may have limited the benefit of inhabiting areas with the highest prey abundance and resulted in fish choosing habitat based on other environmental parameters.

AUTHORS: Rebecca M. Krogman*, Iowa Department of Natural Resources

ABSTRACT: Littoral habitat is an important component of lake and reservoir ecosystems, but is rarely measured or monitored. The importance of habitat integrity has been recognized and measured in lotic systems alongside biological integrity and water quality for decades, but similar habitat measures for lakes and reservoirs are still in their infancy. Two approaches which have been developed recently are the National Lakes Assessment protocol and the European Lake Habitat Survey protocol; both approaches are somewhat similar to each other and are reminiscent of the Qualitative Habitat Evaluation Index for streams. We applied both protocols during summer 2015 to two Iowa reservoirs, Easter Lake and Union Grove Lake. Results were compared between reservoirs and between samples to determine whether one method yielded more useful or reliable data than the other. Extensive discussion of each protocol yielded new perspectives on whether components could be adequately measured, whether potentially useful metrics were not included, and whether each protocol adequately reflected fish habitat in Iowa reservoirs. A new method was then investigated which combined multiple spatial scales, deriving data from remote sensing, lake mapping, and field sampling. Protocols for measuring lentic habitat will be further tested during 2016, with the goal of developing a habitat index which can be used for both monitoring and management of reservoirs.

AUTHORS: Sandra Clark-Kolaks*, Indiana Department of Natural Resources

ABSTRACT: In many Midwest states, including Indiana, large reservoirs are highly utilized by anglers. Also, similar to most reservoirs in the Midwest, reservoirs in Indiana are aging and aquatic habitat is deteriorating or nonexistent. Indiana Department of Natural Resources (DNR) is working to create a reservoir aquatic habitat enhancement program similar to other Midwest states using artificial structures: crib structures, rock piles, Georgia cubes, brush piles, and felled shoreline trees. General recommendations of the number of structures to place in a complex (i.e. 20 cribs per acre) are widely available but the question of how much aquatic habitat is needed is still unanswered. Indiana DNR is attempting to use a quantitative measure of habitat enhancement by calculating a Habitat Enhancement Zone (HEZ). The HEZ is the surface area for the portion of the lake with adequate oxygen levels for fish but deep enough not to obstruct boats. The HEZ is calculated using detailed bathometric maps which are created using Lowrance HDS depth finder and BioBase software. All artificial structures will be placed within this HEZ. We created an impact acreage for structure complexes (i.e. 20 cribs per acre) based on an area slightly greater than the complex surface area due to habitat created along the edges of the structures. Other structures, like brush piles and felled shoreline trees; where documentation of surface area is not available, the best estimate of the area of habitat created was based on an area slightly larger than the structure (length of tree, etc.). Based on these individual structure impact acreages, Indiana DNR hopes to increase available habitat by 5% to 20% in the Habitat Enhancement Zone in project lakes.

AUTHORS: Rebecca M. Krogman*, Iowa Department of Natural Resources; Michelle Balmer, Iowa Department of Natural Resources

ABSTRACT: A water quality index was developed for Iowa’s lakes and reservoirs using ten years of monitoring data from the Iowa Department of Natural Resources’ Lake Monitoring Program. The index ranged between 0 and 100 and was applied to over 130 significant, publicly-owned lakes and reservoirs to rank them by current water quality and to track historical trends in water quality at each location. The index was developed using stepwise logistic regression with water quality parameters from monitoring as predictor variables and water quality ladder score as the response variable. The water quality ladder is a commonly used tool which ties water quality perceptions to tangible aquatic uses; ladder scores had been collected during monitoring since 2004 and could be directly matched with chemical and physical water quality parameter observations. The resulting logistic model included mean depth, Secchi depth, turbidity, total phosphorus concentration, zooplankton density, and an indicator of stratification. Water quality index scores were normally distributed around a mean score of 58.6, with a range of 32.0 to 81.8. The index showed significant relationships with several water quality variables—including chlorophyll a concentration, total nitrogen concentration, and trophic state index—and with some morphometric variables—including mean depth along the longest fetch line. Surprisingly, index scores did not correlate with watershed area:surface area ratio or erosion variables. The index successfully indicated renovations and watershed improvements in several important public waters, but not in others for reasons which were explored. The sensitivity of the index to variance in predictor variables was investigated, and sample sizes for detecting change were modeled.