Midwest Fish & Wildlife Conference 2019

AUTHORS. Patrick M. Kocovsky, US Geological Survey; Nicole R. King, University of Toledo; Eric Weimer, Ohio Department of Natural Resources; Christine M. Mayer, University of Toledo; Song S. Qian, University of Toledo

ABSTRACT. Spawning of Grass Carp Ctenopharyngodon idella in the Great Lakes basin was verified when eight genetically-confirmed, fertilized eggs were collected in the Sandusky River, a tributary to Lake Erie, in June and July 2015. Researchers predicted the fertilization location for those eggs was ~3.9 ± 1 km downstream of Ballville Dam between the State Street and Hayes Avenue bridges within the city limits of Fremont, Ohio. In June 2018, two pieces of evidence permitted verification of the model-predicted spawning location. First, fertilized Grass Carp eggs were collected at several sites from 3.3 km to 18 km downstream of the predicted spawning area 11-14 June. We used water temperature measured in the field at time of capture, developmental stage (± 1 stage) determined by microscopic examination, and published curves relating developmental time to water temperature to estimate time since fertilization for several hundred eggs. We then subtracted developmental time from capture time for each egg to determine the time the egg was fertilized and created a histogram of fertilization times. Second, two mature, diploid female and 14 mature, diploid male Grass Carp were captured by electrofishing conducted within the predicted spawning area during a prescribed management action conducted 12-14 June. Histograms of egg fertilization times overlapped with collection times for mature Grass Carp in the model-projected spawning area, providing additional evidence of the location of the spawning area and validating the modeling method used.

AUTHORS. Kasia Kelly, Meredith B. Nevers, Murulee N. Byappanahalli – U.S. Geological Survey; Charles C. Morris, Joshua Dickey – National Park Service; Dawn Shively, Ashley Spoljaric – Michigan State University

ABSTRACT. Introduced rusty crayfish (Orconectes rusticus) are frequently found in Lake Michigan tributaries during routine fish surveys.  While some locations are heavily occupied by the invasive crayfish, others support only small populations or resist invasion.  Certain streams may be more likely to attract establishment of rusty crayfish populations due to habitat type, existing fish communities, or other biotic and abiotic conditions.  Current monitoring for crayfish in rivers includes laborious sampling such as electroshocking or trapping, but the use of environmental DNA (eDNA) may present a more efficient method. While eDNA has the advantage of broader spatial coverage with less intense effort, the relationship between eDNA estimates and traditional surveys must be established. We explored the relationship between eDNA and electroshocking for detection and quantification of rusty crayfish, along with the interactions with habitat and water quality assessments and fish community surveys. The goal was to assess the usefulness of targeted eDNA in stream surveys and to attempt to model future invasion potential. Copy numbers of rusty crayfish DNA marker by quantitative PCR (qPCR) were positively correlated with electroshocking catch (Pearson R= 0.747, P= 0.033) and crayfish biomass (Pearson R= 0.845, P= 0.008).  The eDNA assay for rusty crayfish discerned between highly and scarcely infested sites in streams of northern Indiana. Fish assemblage data revealed similar species composition in infested and non-infested sites, frequently including green sunfish, creek chub, white sucker, rainbow and brown trout.  Neither eDNA marker nor crayfish count by electroshocking was correlated with any of the water chemistry measures or habitat quality scores, implying that rusty crayfish is highly adaptable to different habitat conditions. Future efforts will include development of a predictive model using the habitat data and fish species composition to predict the future spatial and temporal spread of rusty crayfish between watersheds.

AUTHORS. Jeremy Hammen, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office; Emily Pherigo, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office; Jason Goeckler, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office

ABSTRACT. Successful fish management depends on the ability to quickly and accurately assess populations. This can be challenging when managing invasive species, like Silver Carp, due to the difficulty in capturing these species. Conventional gears can be limited in their ability to efficiently achieve these assessments yet these conventional methods continue to be used, risking the ability to accurately assess a population in a cost effective way. To help address these challenges, an electrified dozer trawl was developed that combined conventional boat electrofishing with a rigid-frame push net. We compared catch rates, size structures, and species diversity from conventional boat electrofishing catch with the electrified dozer trawl in tributaries of the Missouri River, Missouri, to determine which technique more efficiently and precisely assesses a Silver Carp population. The electrified dozer trawl completed sampling transects in nearly half the time and captured twice as many Silver Carp as conventional boat electrofishing. Therefore, it could be included as an assessment tool. Additional benefits of the electrified dozer trawl could extend beyond Silver Carp into the management of native and sportfish. For example, species richness and species accumulation curves were similar between the two gears indicating the potential for use in assessing fish community. Applications for the electrified dozer trawl could benefit fisheries management for several species in many different environments and needs to be explored.

AUTHORS. Benjamin Leonhardt, Purdue University; Benjamin Turschak, Michigan Department of Natural Resources; Austin Happel, Colorado State University; Sergiusz Czesny, University of Illinois, Illinois Natural History Survey; Harvey Boostma, University of Wisconsin-Milwaukee; Jacques Rinchard, SUNY-Brockport; Tomas Höök, Purdue University, Illinois-Indiana Sea Grant

ABSTRACT. Over the past twenty years, Lake Michigan has undergone changes in community composition, nutrient dynamics, and system productivity due to reduced nutrient loading and the introduction of invasive species (e.g., round goby, Neogobius melanostomus; zebra mussel, Dreissena polymorpha; quagga mussel, Dreissena bugensis). There is uncertainty in about how predatory fish in Lake Michigan will adjust their feeding patterns to the observed changes in forage fish abundance. Previous research efforts have primarily focused on the response of salmonids, there has been much less attention given to the piscivorous burbot (Lota lota), a native species of cod found in the cold, offshore regions of Lake Michigan. We investigated burbot feeding patterns in Lake Michigan using diet data from burbot stomachs collected in 2016 and 2017, as well as fatty acid composition and stable isotope ratios of burbot and round goby collected in 2016. Stomach contents revealed that burbot are primarily consuming round goby throughout Lake Michigan, with small contributions from sculpin (deepwater sculpin, Cottus cognatus; slimy sculpin, Myoxocephalus thompsonii), alewife (Alosa pseudoharengus), and other fish. Similarities between the spatio-temporal patterns of fatty acid compositions and stable isotope ratios in burbot and round goby suggest long-term feeding on round goby by burbot. Prior to the invasion of dreissenid mussels and round goby in Lake Michigan, burbot were known to have a diverse diet which included alewife, sculpin, bloater (Coregonus hoyi), and stickleback (Gasterosteidae spp.); however, it appears that burbot now consume almost exclusively round goby, which will likely have implications for the connection of nearshore and offshore food webs in Lake Michigan.

AUTHORS. Samantha Jurecki, Leslie Dorworth, Meredith Nevers, Muruleedhara Byappanahalli, Scott T. Bates – USGS Lake Michigan Ecological Research Station

ABSTRACT. The round goby (Neogobius melanostomus) is an invasive fish species originating from the Black and Caspian Seas that has significantly impacted the ecology and economics of the Great Lakes region. Improving monitoring methods of the round goby will help in creating more efficient, cost-effective strategies for managing this invasive species. Recently, high-throughput sequencing of environmental DNA (eDNA) has been used to increase detection capabilities of fish species in aquatic systems. Metabarcoding approaches such as these allow for effective relative assessments of the abundances of individual species within a community, and thus are well suited for monitoring invasives. Here we use metabarcoding of eDNA to monitor invasive round goby populations in Lake Michigan. Our study focuses on a newly installed artificial reef at Jeorse Park (East Chicago, IN), examining the influence of these structures in supporting native fish populations over those of the round goby. Water samples for our study were collected at five onshore and offshore locations near the reef at Jeorse Park over the course of the 2018 summer season. In order to validate our methods in freshwater, we also took samples during traditional field monitoring expeditions as well as from indoor freshwater tanks with known communities of fish that are native to the Great Lakes. All samples will be sequenced this fall for analysis using the previously described MiFish/MitoFish bioinformatic pipeline.

AUTHORS. Amy E. George, Benjamin H. Stahlschmidt, Cayla L. Carlson – U.S. Geological Survey; Rafael O. Tinoco, Andres F. Prada – University of Illinois; Duane C. Chapman, U.S. Geological Survey

ABSTRACT. Sensory input and systems are critical for organisms to respond to their environment, allowing movement to suitable habitat and potential escape from predators.  While many aspects of grass carp ontogeny have been described, neurosensory development remains unclear.  Previous studies have shown that phototaxis occurs in larval grass carp, which was a basis for the successful deployment of light traps as a collection gear for larval carp.  However, other cues, such as chemotaxis, rheotaxis, and phonotaxis have not been studied for grass carp larvae, and it remains unclear when a response would begin to occur.  Using behavioral tests, we looked at phonotaxis and chemotaxis from initial gas bladder inflation to the development of the second gas bladder chamber (the period where larvae leave the mainstem river and move into nursery areas). Rheotaxis was examined from hatch through gas bladder inflation by quantifying orientation in a laboratory flume.  Grass carp larvae showed no preference for any chemosensory stimulus tested, and auditory stimuli elicited very little reaction except at frequencies above 1000hz and volumes up to 30 decibels higher than ambient noise.  Larvae showed a consistent orientation facing into the flow at most developmental stages, suggesting that rheotaxis may be the earliest developing sense and most critical for navigation. By knowing how and when different sensory systems develop in grass carp larvae, control measures may be developed that attract or deter larvae from specific areas.

AUTHORS. Sarah K. Lamar, Charlyn G. Partridge – Grand Valley State University's Annis Water Resources Institute

ABSTRACT. Baby’s breath (Gypsophila paniculata) is an invasive herbaceous perennial that has established throughout much of North America. Within the Michigan coastal dune system the weed effectively outcompetes native plant species adapted to the unique environment and forms monotypes that threaten the federally protected Pitcher’s Thistle (Cirsium pitcheri). Baby’s breath has also established populations in the sage-steppe of central Washington state, a distinct habitat characterized by equally harsh environmental conditions. To understand the invasion success of G. paniculata between these two locations we assessed environmental, genetic, and traits differences associated with plants from these different environments. In the summer of 2018, soil, tissue, and seeds were collected from these two locations. Soil chemistry was analyzed to characterize these two unique environments, microsatellite markers were used to identify genetic similarity among these populations, and a common garden germination study was conducted to examine differences in germination rates.Preliminary results show that despite establishing in geographically and environmentally distinct habitats, as characterized by soil data, G. paniculata populations in both Chelan, Washington and Petoskey, Michigan are more genetically similar than initially expected. These results can be viewed in a larger context by assessing existing herbarium records of G. paniculata to attempt to track its spread across N. America. Germination study results further characterize differences between these two potentially locally-adapted populations. These data can be used for the greater purpose of informing targeted management of this invasive species.