GLOBAL PATTERNS OF FRESHWATER FISH COMMUNITIES IN MEDITERRANNEAN BIOMES Elif Esther Fehm-Sullivan B.S., California State University, Sacramento, 2003 THESIS Submitted in partial satisfaction of the requirements for the degree of MASTER OF SCIENE in BIOLOGICAL SCIENCES at CALIFORNIA STATE UNIVERSITY, SACRAMENTO FALL 2010 GLOBAL PATTERNS OF FESHWATER FISH COMMUNITIES IN MEDITERRANNEAN BIOMES A Thesis by Elif Esther Fehm-Sullivan Approved by: __________________________________, Committee Chair Jamie Kneitel, Ph.D. __________________________________, Second Reader Brett Holland, Ph.D. __________________________________, Third Reader Patrick Foley, Ph.D. __________________________________ Date ii Student: Elif Esther Fehm-Sullivan I certify that this student has met the requirements for format contained in the University format manual, and that this thesis is suitable for shelving in the Library and credit is to be awarded for the thesis. __________________________, Graduate Coordinator ___________________ Susanne Lindgren, Ph.D. Date Department of Biological Sciences iii Abstract of GLOBAL PATTERNS OF FRESHWATER FISH COMMUNITIES IN MEDITERRANNEAN BIOMES by Elif Esther Fehm-Sullivan Explaining patterns of species richness is a central theme in community ecology. Ecologists have focused on local (within a site), regional (among sites in a given region), or geographical (among regions) explanations of diversity patterns. In the case of freshwater fish, studies illustrate that biological factors (competition and predation), along with physical factors (habitat diversity, water chemistry, flow regime, temperature and channel morphology), interact to influence species richness within and among communities and that both operate within a range of spatial scales. This study identified global patterns of species richness and trophic diversity in twelve Mediterranean biome freshwater fish communities located on six continents. Differences were found in both species richness and trophic diversity between continental river basins. This study also examined energetic, ecological, and historical factors that may explain freshwater fish species richness and trophic diversity among Mediterranean biome river basins. The energetic factor, average annual discharge, was found to explain species richness; and that none of the seven factors measured explained trophic diversity. This result is contrary to studies that have shown net primary productivity as explaining species richness in global freshwater fish communities. The difference presented in this iv study states that all basin studies were in one habitat type, the Mediterranean biome, whereas other studies examined several varying habitat types. The resulting specific knowledge can help conserve species richness and manage river basins altered by human activity. ___________________________, Committee Chair Jamie Kneitel, Ph.D. ___________________________ Date v DEDICATION In loving memory of Sherwood Anthony Fehm Jr. and Saba Phyllis Fehm-Sullivan. vi ACKNOWLEDGMENTS Completing a Masters is truly a marathon event, and I would not have been able to complete this journey without the aid and support of countless people over the past seven and a half years. I would like to express my gratitude to my supervisor, Dr. Jamie Kneitel, whose expertise, understanding, and patience added considerably to my graduate experience. I appreciate his vast knowledge and skill in many areas (e.g., statistical analysis, community ecology, and dry humor), and his assistance in writing. I also want to thank him for his calm reserve during times of stress. I would like to thank the other members of my committee, Dr. Bret Holland, and Dr. Patrick Foley for the assistance they provided at all levels of my thesis project. Finally, I would like to thank Dr. Susanne Lindgren, the Graduate Student Advisor, for giving me the opportunity to finish my thesis. I would like to give my eternal gratitude to my father James E. Sullivan for the guidance and wisdom that he has given me throughout my life. I have been able to develop and grow as an individual as a result. He provided me with moral, emotional, and writing support during this entire process. I doubt I will ever be able to convey my appreciation fully. I must also acknowledge the quiet, constant, intense and enduring support of my mother Sadie Çançar Sullivan. A very special thank you goes to Dr. Barbara Cordonii, who years ago diagnosed my learning disabilities, and with whose tutelage enabled me to reach this level of vii education. Without her motivation and encouragement, I would not have considered a graduate career. viii TABLE OF CONTENTS Page Dedication .......................................................................................................................... vi Acknowledgments............................................................................................................. vii List of Tables .......................................................................................................................x List of Figures .................................................................................................................... xi Introduction ..........................................................................................................................1 Methods................................................................................................................................9 Results ................................................................................................................................11 Discussion ..........................................................................................................................24 Conclusion .........................................................................................................................29 Appendix A. Trophic level richness per drainage basin. ...................................................32 Appendix B. Data sources ..................................................................................................33 Appendix C. Species lists and trophic level .......................................................................34 Appendix D. Table of environmental factor values per drainage basin ............................42 Appendix E. Calculation table for NPP .............................................................................43 Literature Cited ..................................................................................................................44 ix LIST OF TABLES Page Table 1. Trophic Level ANOVA ......................................................................................14 Table 2. Species Richness ANOVA .................................................................................16 Table 3. Continental Trophic Richness ANOVA. ............................................................18 Table 4. Multiple Regression on Species Richness and Trophic Diversity. .....................21 x LIST OF FIGURES Page Figure 1. Global map of Mediterranean Biome Locations .................................................8 Figure 2. Trophic Level Histogram. .................................................................................15 Figure 3. Species Richness Histogram. .............................................................................17 Figure 4. Continental Trophic Species Richness Histogram. ...........................................19 Figure 5. Continental Community Composition Chart. ....................................................20 Figure 6. Species Richness Regression with the San Joaquin River. ...............................22 Figure 7. Species Richness Regression without the San Joaquin River. ..........................23 xi 1 INTRODUCTION A central issue in both biogeography and community ecology is to understand the factors that shape species richness patterns across different spatial scales (Cody and Mooney, 1978; Griffiths, 2006). Among vertebrates, fish have been one of the most intensely studied groups for local (within river), regional (among rivers), and geographical (among regions) community structure. Numerous common patterns in fish community organization have been identified among distinct river basins at several different spatial scales. For example, at a local scale, physical factors appear to determine species richness in variable environments (Capone and Kushlan, 1991). On larger spatial scales (regional and geographical), physical factors such as area, total discharge, and primary productivity, along with historical factors such as speciation rates and dispersal are the major determinant of species richness and regulate the importance of local-scale factors (Lamoureux et al., 2002). To better understand freshwater fish communities, ecologists have studied several aspects of community structure. These include biogeographic histories and their relation to the distribution of freshwater fishes (Novacek, 1976; Bernatchez and Wilson, 1998; McDowall, 2002; Landini and Sorbini, 2005; Goren and Ortal, 1998), diversity of trophic categories (feeding patterns) (Tonn, 1990; Winemiller, 1991; Behrens and Lafferty, 2007; Daufresne and Boёt, 2007; Erös, 2007; Mittelbach et al., 2007; Lévêque et al., 2008), and species richness (Hawkins et al., 2003; Oberdorff et al., 1995; Guégan et al., 1998; Oberdorff et al., 2001; Griffiths, 2006; Reyjol et al., 2007). 2 The inland water fishes of the Mediterranean have been studied since the first description