Eastern Kentucky University Encompass Online Theses and Dissertations Student Scholarship January 2018 Population Size And Habitat Association Of Etheostoma Nebra, The Buck Darter, Using Abundance Modeling In The Buck Creek System, Cumberland River Drainage, Kentucky Harold Davidson Black Eastern Kentucky University Follow this and additional works at: https://encompass.eku.edu/etd Part of the Terrestrial and Aquatic Ecology Commons Recommended Citation Black, Harold Davidson, "Population Size And Habitat Association Of Etheostoma Nebra, The Buck Darter, Using Abundance Modeling In The Buck Creek System, Cumberland River Drainage, Kentucky" (2018). Online Theses and Dissertations. 512. https://encompass.eku.edu/etd/512 This Open Access Thesis is brought to you for free and open access by the Student Scholarship at Encompass. It has been accepted for inclusion in Online Theses and Dissertations by an authorized administrator of Encompass. For more information, please contact [email protected]. POPULATION SIZE AND HABITAT ASSOCIATION OF ETHEOSTOMA NEBRA, THE BUCK DARTER, USING ABUNDANCE MODELING IN THE BUCK CREEK SYSTEM, CUMBERLAND RIVER DRAINAGE, KENTUCKY BY HAROLD DAVIDSON BLACK Submitted to the Faculty of the Graduate School of Eastern Kentucky University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE 2018 © Copyright by HAROLD DAVIDSON BLACK 2018 All Rights Reserved. ii ACKNOWLEDGEMENTS I would like to thank my parents, Harold and Patricia Black, for their continued love and support during this academic pursuit. Ethan Buland and Peter Grap provided field assistance during the bulk of this study, and Alex Baecher offered his knowledge and insight on statistics. I thank Drs. Amy Braccia, David Brown, and Michael Floyd for serving on my graduate advisory committee and for providing helpful editorial comments on the final draft of the manuscript. I would also like to give special thanks to my advisor, Dr. Sherry Harrel, whose advice, patience, and encouragement made this academic pursuit possible. Funding for this research was provided by the United States Fish and Wildlife Service, the Kentucky Waterways Alliance, the Kentucky Department of Fish and Wildlife Resources, the Kentucky Society of Natural History, and Eastern Kentucky University Department of Biological Sciences. iii ABSTRACT Etheostoma nebra (Buck Darter) is a recently described fish species confined to the Buck Creek system, Cumberland River drainage, Kentucky. A 2010-2012 survey of Buck Creek by Kentucky Department of Fish and Wildlife Resources personnel observed E. nebra at 2 of 47 historical sites. Within the entire system, individuals were found only in Flat Lick Creek around the confluence of two spring-fed tributaries, Big Spring Branch and Stewart Branch. The objectives of this study were to: (1) determine population size, demographics, and habitat association of E. nebra in Big Spring Branch and Stewart Branch, (2) evaluate habitat conditions both within extant range and historical range, (3) complete fish surveys within the species’ historical range, and (4) monitor and compare water quality at extant and historical localities within the system. Totals of 75 and 86 individuals of E. nebra were captured in Big Spring Branch and Stewart Branch, respectively; however, no individuals were observed in Buck Creek or other tributaries. In both extant populations, average total Length of males exceeded that of females (TLmales = 63.5 mm, TLfemales = 54.5 mm). Using N-Mixture models to predict abundance based on measured habitat variables and to account for imperfect detection, the total population in both streams was estimated to consist of approximately 17,000 individuals. Analyses of the two occupied streams yielded higher abundance estimates of E. nebra in Big Spring Branch. Important habitat variables associated with their abundance included a mixture of substrate size classes resulting in habitat complexity. Pebble and cobble showed positive relationships with predictions of increased E. nebra abundance. Comparison of occupied and unoccupied plots within Big Spring Branch and iv Stewart Branch showed significant differences in most of the habitat variables (i.e. maximum depth, average depth, median substrate type, and presence of canopy). However, when unoccupied plots from historical streams were added and compared to occupied plots, few habitat variables showed significant differences. This indicated that unoccupied plots at historical streams had similar habitat conditions compared to occupied plots of Stewart and Big Spring Branch, and thus, habitat conditions were most likely not contributing to the disappearance of E. nebra at these streams. Average conductivity was higher in occupied streams than historical streams across seasons (Occupied: 342 μS/cm, Unoccupied: 146 μS/cm). Additionally, with more springs present, occupied streams exhibited warmer average winter temperatures and lower average summer temperatures than unoccupied streams (Range of monthly temperatures, Occupied: 11.6- 20.6 ℃, Unoccupied: 9.2- 23.9 ℃). Spawning activity of E. nebra was observed through July, and lower summer water temperatures could be a contributing factor to the species’ persistence in these two streams. These results will aid cooperating natural resource agencies in making decisions toward management and conservation of this imperiled species. v TABLE OF CONTENTS CHAPTER PAGE Chapter I: Introduction ....................................................................................................... 1 Chapter II: Methods ............................................................................................................ 5 Study Area ............................................................................................................... 5 Study Design............................................................................................................ 7 Physicochemical, Habitat, and Fish Sampling: Big Spring Branch and Stewart Branch ..................................................................................................................... 8 Physiochemical, Habitat, and Fish Sampling: Buck Creek System .......................... 9 Monitoring of Seasonal Stream Temperature and Conductivity .......................... 10 Data Analysis: Population Structure ..................................................................... 13 Data Analysis: N-Mixture Modeling Population Estimate .................................... 13 Data Analysis: Habitat Association ....................................................................... 14 Data Analysis: Temperature and Conductivity Data ............................................. 15 Chapter III: Results ............................................................................................................ 17 Population Structure ............................................................................................. 17 Population Estimates ............................................................................................ 20 Habitat Association ............................................................................................... 20 Fish Surveys of Historical Range ........................................................................... 28 HOBO Logger Data ................................................................................................ 28 Chapter IV: Discussion ...................................................................................................... 32 References ........................................................................................................................ 41 vi APPENDICES ...................................................................................................................... 45 Appendix A: Summary of quantitative survey reaches within Big Spring Branch and Stewart Branch, Buck Creek system, Kentucky (2017). .................................. 46 Appendix B: Summary of 2016-2017 qualitative survey reaches in the Buck Creek system, Kentucky. ........................................................................................... 48 Appendix C: Summary of data logger locations within the Buck Creek system, Kentucky (2017). ............................................................................................. 50 Appendix D: AICc table of N-Mixture models for Etheostoma nebra abundance in Big Spring Branch and Stewart Branch, Buck Creek system, Pulaski County, KY (2017). ............................................................................................................. 52 Appendix E: Summary of fishes observed at all qualitative and quantitative (not included in the population estimate) reaches within the Buck Creek system, Kentucky (2016-2017). .................................................................................... 54 vii LIST OF FIGURES FIGURE PAGE Figure 1. Map of the Buck Creek system in Pulaski, Lincoln, and Rockcastle counties of Kentucky; showing watershed area, ecoregion boundaries, and springs. ........ 6 Figure 2. Map of Big Spring Branch and Stewart Branch within the Flat Lick Creek system, showing 2017 survey sites and reaches. .............................................. 8 Figure 3. Map showing the sites sampled in the 2016-2017 survey efforts of historical collection locations and other localities within the Buck Creek system, Kentucky. ........................................................................................................