THE INFLUENCE OF FLOW ALTERATION ON INSTREAM HABITAT AND FISH ASSEMBLAGES By NICOLE FARLESS Bachelor of Science in Agriculture Sciences and Natural Resources Oklahoma State University Stillwater, Oklahoma 2012 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE December, 2015 THE INFLUENCE OF FLOW ALTERATION ON INSTREAM HABITAT AND FISH ASSEMBLAGES Thesis Approved: Shannon Brewer Thesis Adviser Todd Halihan Jim Long ii ACKNOWLEDGEMENTS There are many people that I need to acknowledge for their help and support throughout my Master’s research. I would like to start off thanking my advisor, Dr. Shannon Brewer. Shannon not only continually helped me broaden my knowledge of science and research but also invested her time to improve my practical knowledge as well. I would also like to thank my funding source, The Nature Conservancy and the Oklahoma Cooperative Fish and Wildlife Research Unit. I would also like to thank Brian Brewer for all of his help building and developing the thermal tolerance lab. Without him I could not have completed my temperature tolerance study. I am indebted to many graduate students that have assisted with statistical, theoretical, and field work. Especially, Jonathan Harris and Robert Mollenhauer, who have volunteered countless hours editing my writing and assisting with data analysis. I would also like to thank Dr. Jim Shaw, my undergraduate advisor, for recognizing my potential and encouraging me to attend graduate school. Without him I would have never considered furthering my education. I would not have been able to complete this project without the help of the many technicians that worked hard for me in the lab and in the field: Desiree Williams, Frances Marshall, Joshua Mouser, Bailey Johnson, Emily Gardner, Spencer Wood, Cooper Sherrill, and Jake Holliday. Finally, I would like to thank my family, especially my parents for their unconditional love and support. iii Acknowledgements reflect the views of the author and are not endorsed by committee members or Oklahoma State University. Name: NICOLE FARLESS Date of Degree: DECEMBER, 2015 Title of Study: THE INFLUENCE OF FLOW ALTERATION ON INSTREAM HABITAT AND FISH ASSEMBLAGES Major Field: NATURAL RESOURCES ECOLOGY AND MANAGEMENT Abstract: Globally, the instream habitat and biotic community of riverine systems are declining. The primary threat to rivers is flow regime alteration through dams, landscape alteration, and climate change. The natural flow regime is the natural pattern of a rivers flow. The flow regime is vital for maintaining abiotic and biotic stream components, including the thermal regime of rivers (i.e., average, maximum and minimum temperature). Increased stream temperature can influence species direct and indirect survival, as well as many life history events. The objectives of my Master’s research were to 1) develop flow-ecology relationships for stream habitat and fishes from the Arbuckle Mountain and Ozark Highland ecoregion and 2) determine the maximum thermal tolerance of stream fishes from the Arbuckle Mountains. Flow-ecology relationships were determined through the development of linear models for both stream habitat (i.e., deposited sediment, channel-unit diversity, residual-pool depth, and bankfull width-to- depth ratio) and fish assemblages (i.e., coarse-scale reproductive guilds and finer-scale reproductive-taxonomy guilds) to determine their relationship with flow alteration. These flow-ecology models showed that many stream abiotic and biotic characteristics were positively influenced by dynamic flow conditions, such as, increased magnitude and number of reversals. For example, stream fish diversity and reproductive guild diversity were positively influenced by increased maximum flows. Abiotic and biotic flow-ecology relationships can further improve the development of environmental-flow standards. I also determined the critical thermal maxima (CTM) of 15 species and the longer-term tolerance of 10 fish species from the Arbuckle Mountains. Longer-term studies had both a spring-fed and non spring-fed treatment that mimicked the thermal regime of Arbuckle Mountain streams. Comparing the results of the CTM and the longer-term study improves our understanding of species thermal tolerance and acclimation ability. Results showed that pelagic species had higher thermal tolerances than benthic species and had greater acclimation ability. Results from both objectives provide insight on the susceptibility of species to future flow and thermal alterations. This can be used to predict future fish assemblage changes and determine species of conservation concern. iv TABLE OF CONTENTS Chapter Page I. INTRODUCTION ......................................................................................................1 Introduction ..............................................................................................................1 Objectives ................................................................................................................6 References ................................................................................................................7 II. INFLUENCE OF FLOW REGIME ALTERATIONS ON FISH ASSEMBLAGE AND THE ABIOTIC STRUCTURE OF STREAMS ...........................................12 Abstract ..................................................................................................................12 Introduction ............................................................................................................13 Study Area .............................................................................................................17 Methods..................................................................................................................18 Results ....................................................................................................................22 Discussion ..............................................................................................................26 References ..............................................................................................................45 Appendices .............................................................................................................60 III. THERMAL TOLERANCE OF STREAM FISHES EXPOSED TO VARYING THERMAL REGIMES ..........................................................................................67 Abstract ..................................................................................................................67 Introduction ............................................................................................................68 Study Area .............................................................................................................72 Methods..................................................................................................................72 Results ....................................................................................................................75 Discussion ..............................................................................................................77 References ..............................................................................................................89 Appendices .............................................................................................................97 v LIST OF TABLES Table Page Chapter 2. Table 1 .....................................................................................................35 Chapter 2. Table 2 .....................................................................................................36 Chapter 3. Table 1 .....................................................................................................83 vi LIST OF FIGURES Figure Page Chapter 2. Figure 1 ...................................................................................................37 Chapter 2. Figure 2 ....................................................................................................38 Chapter 2. Figure 3 ...................................................................................................39 Chapter 2. Figure 4 ...................................................................................................40 Chapter 2. Figure 5 ...................................................................................................41 Chapter 2. Figure 6 ...................................................................................................42 Chapter 2. Figure 7 ...................................................................................................43 Chapter 2. Figure 8 ...................................................................................................44 Chapter 3. Figure 1 ...................................................................................................84 Chapter 3. Figure 1 ...................................................................................................85 Chapter 3. Figure 2 ...................................................................................................86 Chapter 3. Figure 3 ...................................................................................................87 Chapter 3. Figure 4 ...................................................................................................88 vii