ABIOTIC AND BIOTIC FACTORS AFFECTING SIZE-DEPENDENT CRAYFISH (ORCONECTES OBSCURUS) DISTRIBUTION, DENSITY, AND SURVIVAL A dissertation submitted to Kent State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy by Jennifer M. Clark May 2009 Dissertation written by Jennifer M. Clark B.S., Kent State University, 2003 Ph.D., Kent State University, 2009 Approved by __________________________________, Chair, Doctoral Dissertation Committee Mark W. Kershner __________________________________, Members, Doctoral Dissertation Committee Laura G. Leff __________________________________ Joseph R. Holomuzki __________________________________ Andrew L. Moore __________________________________ Accepted by __________________________________, Chair, Department of Biological Sciences James L. Blank __________________________________, Dean, College of Arts and Sciences John R. D. Stalvey ii TABLE OF CONTENTS LIST OF FIGURES ……………………………………………………………………..vii LIST OF TABLES ……………………………………………………………………….xi ACKNOWLEDGMENTS …………………………………………………………........xii CHAPTER I. Introduction………………………………………………………………..1 Current velocity…………………………………………………...2 Sediment grain size and heterogeneity……………………………4 Water depth………………………………………………………..5 Predation…………………………………………………………..6 Competition………………………………………………………..8 Flooding………………………………………………………….10 Organismal distribution………………………………………….11 Dissertation organization………………………………………...11 References………………………………………………………..13 II. Size-dependent effects of Visible Implant Elastomer marking on crayfish (Orconectes obscurus) growth, mortality, and tag retention…………….22 Abstract…………………………………………………………..22 Introduction………………………………………………………23 Methods…………………………………………………………..26 Experimental procedure………………………………….27 Statistical analyses…………………………………….....27 Results…..………………………………………………………..29 Discussion………………………………………………………..33 Acknowledgments………………………………………………..35 References………………………………………………………..36 III. Grain size and sorting effects on size-dependent responses by lotic crayfish to high flows…………………………………………………….39 Abstract…………………………………………………………..39 Introduction………………………………………………………40 Methods…………………………………………………………..43 iii Flume experiments……………………………………….43 Grain size effects…………………………………43 Grain sorting effects……………………………...44 Statistical analyses……………………………….45 Crayfish size distributions in the field…………………...46 Crayfish size, current velocity, and grain characteristics……………………………………46 Statistical analyses……………………………….47 Results……………………………………………………………48 Flume Experiments………………………………………48 Grain size effects…………………………………48 Grain sorting effects……………………………...54 Crayfish size distributions in the field…………………...55 Crayfish size, current velocity, and grain characteristics…………………………………….55 Discussion………………………………………………………..59 Crayfish responses to elevated flows in the flume……….59 Crayfish size distributions in relation to grain characteristics in the field………………………………..62 Acknowledgments………………………………………………..65 References………………………………………………..............66 IV. Short- and long-term impacts of a major flood event on crayfish (Orconectes obscurus) in a forested stream……………………………...74 Abstract…………………………………………………………..74 Introduction………………………………………………………75 Methods…………………………………………………………..78 Study site description…….……………………………....78 Short-term assessment of flooding effects on crayfish…..79 Mark-recapture of crayfish during flooding versus baseflow conditions………………………………………………...85 Long-term assessment of flooding effects on crayfish…..86 Analysis of short- and long-term assessment…………….87 Results…..………………………………………………………..88 Short-term assessment of flooding effects on crayfish…..88 Mark-recapture of crayfish during flooding versus baseflow conditions………………………………………………...93 Long-term assessment of flooding effects on crayfish…..98 Discussion………………………………………………………103 Acknowledgments………………………………………………110 References………………………………………………………111 iv V. Habitat-specific effects of grain size, current velocity, water depth, and predation risk on size-dependent crayfish distributions………………...118 Abstract…………………………………………………………118 Introduction……………………………………………………..119 Methods…………………………………………………………123 Field site and habitat descriptions………………………123 Habitat-specific abiotic measurements and crayfish/fish survey…………………………………………………...124 Statistical analyses………………………….......125 Survey of predatory fish diets…………………………..127 Predation assays………………………………………...128 Statistical analyses……………………………...131 Grain size manipulation experiment……………………132 Statistical analyses……………………………...134 Results…..………………………………………………………134 Habitat-specific abiotic measurements and crayfish/fish survey…………………………………………………...134 Crayfish survey…………………………………134 Fish predator survey…………………………….137 Crayfish and predatory fish comparisons………140 Summer 2005 Principal Components Analysis...140 Survey of predatory fish diets…………………………..146 Predation assays………………………………………...146 Summer 2005…………………………………...146 Spring 2006……………………………………..152 Summer 2006…………………………………...152 Seasonal comparisons…………………………..155 Habitat-specific abiotic effects on survival……..156 Grain size manipulation experiment……………………157 Discussion………………………………………………………160 General Conclusions……………………………………………168 Acknowledgments………………………………………………169 References………………………………………………………171 VI. Size-structured crayfish (Orconectes obscurus) responses to lotic fishes: coupling field survey with behavioral assays…………………………..180 Abstract…………………………………………………………180 Introduction……………………………………………………..181 Methods…………………………………………………………184 Size relationships in the field…………………………...184 Statistical analyses……………………………………...186 v Y-maze experiments……………………………………187 Experimental animals…………………………..187 Crayfish behavioral responses to fish and other crayfish………………………………………….187 Statistical analyses……………………………………...190 Results…..………………………………………………………191 Size relationships in the field…………………………...191 Crayfish behavioral responses to fish and other crayfish…………………………………………….……200 Discussion………………………………………………………200 Acknowledgments………………………………………………210 References………………………………………………………211 VII. Habitat overlap and resource partitioning between a lotic fish assemblage and crayfish (Orconectes obscurus) in a forested stream………………217 Abstract…………………………………………………………217 Introduction……………………………………………………..218 Methods…………………………………………………………221 Habitat-specific crayfish and fish distribution survey….221 Statistical analyses……………………………………...223 Food web interactions between crayfish and fish………225 Stable isotope collection………………………..225 Stable isotope preparation………………………226 Statistical analyses……………………………………...226 Results…..………………………………………………………227 Discussion………………………………………………………245 Acknowledgments………………………………………………261 References………………………………………………………262 VIII. Discussion and Synthesis……………………………………………….271 Importance of study…………………………………………….275 References………………………………………………………278 vi LIST OF FIGURES CHAPTER 1. Introduction Figure 1. Abiotic and biotic factors potentially affecting distribution patterns of the crayfish Orconectes obscurus in stream ecosystems…………………………3 CHAPTER 2. Size-dependent effects of Visible Implant Elastomer marking on crayfish (Orconectes obscurus) growth, mortality, and tag retention Figure 2. Abdominal somite of a male Orconectes obscurus tagged with red Visible Implant Elastomer (VIE)………………………………………………...28 Figure 3. Average number of molts and average growth per molt of control and tagged juvenile and adult Orconectes obscurus………………………………….32 CHAPTER 3. Grain size and sorting effects on size-dependent responses by lotic crayfish to high flows Figure 4. Number of crayfish dislodged at each current velocity interval on small pebbles, large pebbles, small cobbles, and well, moderately, and poorly sorted grain treatments…………………………………………………………………..50 Figure 5. Average activity time of crayfish during each 5-minute current velocity interval on small pebbles, large pebbles, small cobbles, and well, moderately, and poorly sorted grain treatments…………………………………………………...53 Figure 6. Average crayfish carapace length at each average current velocity, grain size, and sorting index in each sample habitat…………………………………...57 CHAPTER 4. Short- and long-term impacts of a major flood event on crayfish (Orconectes obscurus) in a forested stream Figure 7. Hydrograph of the West Branch of the Mahoning River, Ravenna, Ohio, USA from 30 August-15 September 2005………………………………...83 vii Figure 8. Total density of crayfish captured via electroshocking from days 0-16 in the shallow pool and riffles 1 and 2…………………………………………..90 Figure 9. The density of small and large crayfish captured via electroshocking in the shallow pool and riffles 1 and 2……………………………………………...92 Figure 10. The proportion of tagged crayfish recaptured on post-flood days 2-16 in the shallow pool and riffles 1 and 2…………………………………………...95 Figure 11. The proportion of crayfish recaptured from original and baseflow tagging events……………………………………………………………………97 Figure 12. Total crayfish density of small and large crayfish captured via electroshocking for long-term assessment of flooding on the crayfish population in the shallow pool and riffles 1 and 2………………………………………….100 Figure 13. Total crayfish density of small and large crayfish captured via electroshocking in 12 channel units for long-term assessment of flooding on the crayfish population……………………………………………………………...102 CHAPTER 5. Habitat-specific effects of grain size, current velocity, water depth, and predation risk on size-dependent crayfish distributions Figure 14. Habitat-specific seasonal densities of small, medium,