LIFE HISTORY AND ECOLOGY OF INVASIVE LIONFISH POPULATIONS IN THE NORTHERN GULF OF MEXICO: IMPACTS TO NATIVE REEF FISH COMMUNITIES AND THEIR POTENTIAL MITIGATION By KRISTEN ANN DAHL A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2019 © 2019 Kristen Ann Dahl To Mom & Dad, Mema, and Uncle Steven ACKNOWLEDGMENTS I could not have accomplished my PhD without the backing of my family and friends, who have always encouraged my career aspirations. To Mema (Velma Collier) and Uncle Steven (Dahl), two of the strongest people I have ever known, who are no longer here to see this achievement but inspire me to this day. I am grateful for my parents, sisters, Lana and Shea, my grandparents, and Tom TinHan, who make life worth living. They kept me level-headed, never failed to believe in me, and helped me move from Florida to Alabama, and back again. I cherish the trips they took to visit in Alabama for Mardi Gras parades and balls, and in Gainesville for football games at The Swamp, and trips to Ichetucknee and Cedar Key. Tom, thank you for always understanding the struggles of this degree, stemming any self-doubt, and tolerating our distance over the years. Thanks to Brian Klimek, Whitney Scheffel, and Steve Garner for being the best roommates I could ask for over the last four years. Thanks to Matt and Brittany Knee and the Anderson family for your encouragement over many more years. Your friendship and support have lifted me through uncertain times. I also must thank my dogs, Kiah and Dill, for forcing me to stay active, and always giving me something to laugh about. I would not be here and could not have done this project without the support and guidance of my advisor, Dr. Will Patterson. From the time I first met Will during my undergraduate degree, he has mentored me and allowed me to realize my own potential as a scientist. Will has always led by example and I strive to be as driven, accomplished, and respected as he is. I thank him for providing me endless support to obtain my degree and attend professional opportunities at local, state, national, and international conferences. I thank him for his humor and compassion in difficult times. I 4 consider myself quite lucky to have had him as a teacher and mentor and have learned so much during this experience. After this, I plan to “keep my foot on the gas” and to make him proud. I thank my committee members, Dr. Tom Frazer, Dr. Mike Allen, and Dr. Dave Portnoy, for agreeing to take me on as an advised student, and for their guidance and expertise during this process. I consider myself fortunate to have had such an invested, yet easy-going supervisory committee. I thank Dave for welcoming me into his lab at Texas A&M-Corpus Christi to learn the molecular skills necessary to apply microsatellite genotyping. I thank Mike for his support, instruction, and excitement about my project over the years beginning at the NMFS RTR Lionfish Ecosystem Modeling Workshop. I thank Tom for his help navigating my transfer to UF, as he has been a member of my committee from the start. I appreciate the time he took to explain what to expect as I neared various hurdles of the PhD. I thank other mentors from Dauphin Island Sea Lab, Alison Robertson, Alice Ortmann, and Ken Heck. Special thanks to Alice and Alison for assisting with molecular methodology that became an important and novel part of this project. Thanks to Dick Snyder for being a fantastic teacher and mentor, and for his contributions to my lionfish removal experiment. I thank Derek Hogan, John Johnson and John Gold for welcoming me at TAMU-CC and for contributions to the development of my microsatellite genotyping work. I thank Morgan Edwards for her assistance and experience in aging lionfish otoliths. Next, I thank Dalton Kennedy, Clint Retherford, Scott Bartel, Bryan Clark & Anna Clark, Josh & Joe Livingston, Andy Ross, Alex Fogg, Bob & Carol Cox, Grayson Shepherd, Michael Day, Jeremy Porter, Kylie Gray and Meaghan Faletti for help in 5 scuba diving and collecting thousands of lionfish. I thank charter vessel captains Johnny Greene, Gary Jarvis, Josh Livingston, Sean Kelley, and Seth Wilson and their crews for aid in ROV sampling. You all have made enormous contributions to this work, and I admire your abilities and sheer determination to fight this invasive species. Above all, you are great people who I enjoyed spending time with over the years of this project. I am indebted to a great deal of people that helped shape my graduate school journey. I have worked at two labs in pursuit of my PhD - Dauphin Island Sea Lab and here at the University of Florida. When I started out in the lab, I was the only woman in a lab of men. I will always remember times spent debating endless subjects in the lab and vying for who would stay working the latest. I thank Joe Tarnecki and Steve Garner for their help and incredible skill with ROV operating. I thank Joe, again, for help learning video analysis, and diet analysis, and Brian Klimek, Miaya Glabach, Steve Garner, Michael Norberg, Justin Lewis, Jordan Bajema, Beverly Barnett, Erin Bohaboy, Holden Harris, Joe Kuehl, Lauren Still, Gracie Barnes and Sarah Friedl for help in the field and laboratory. I thank Amanda Barker, Lei Wang, Pearce Cooper, Natalie Ortell, Pavel Dimens, Shannon O’Leary, Dannielle Kulaw, Liz Hunt, Dom Swift, and Stuart Willis for support in molecular labs at DISL and TAMU-CC. The thousands of hours spent aboard offshore vessels, processing whole lionfish, reading ROV videos, pipetting, cutting otoliths, and writing was made faster, more efficient, and much more fun with all of your help. Finally, thanks to all the other friends I have made from DISL and UF during my PhD, who are now spread out at STEM jobs across the country. To all those that gave me camaraderie, feedback, motivation, and charity, I thank you. 6 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST OF TABLES .......................................................................................................... 10 LIST OF FIGURES ........................................................................................................ 12 LIST OF ABBREVIATIONS ........................................................................................... 15 ABSTRACT ................................................................................................................... 17 CHAPTER 1 INTRODUCTION AND JUSTIFICATION FOR STUDY........................................... 19 2 HABITAT-SPECIFIC DENSITY AND DIET OF RAPIDLY EXPANDING POPULATIONS OF INVASIVE RED LIONFISH, PTEROIS VOLITANS, POPULATIONS IN THE NORTHERN GULF OF MEXICO ..................................... 29 Materials and Methods............................................................................................ 32 Lionfish Density Estimates ............................................................................... 32 Sampling Lionfish Tissues ................................................................................ 34 Diet Analysis ..................................................................................................... 35 Muscle Stable Isotope Analysis ........................................................................ 36 Results .................................................................................................................... 37 Lionfish Density and Size ................................................................................. 37 Lionfish Diet Analysis ....................................................................................... 38 Muscle Stable Isotope Analysis ........................................................................ 41 Discussion .............................................................................................................. 42 Lionfish Density Trends .................................................................................... 42 Lionfish Trophic Ecology in the nGOM ............................................................. 44 Conclusions and Implications ........................................................................... 47 3 DNA BARCODING SIGNIFICANTLY IMPROVES RESOLUTION OF INVASIVE LIONFISH DIET IN THE NORTHERN GULF OF MEXICO ..................................... 60 Materials and Methods............................................................................................ 63 Study Location and Specimen Collection ......................................................... 63 Visual Gut Content Analysis ............................................................................. 63 DNA Barcoding Preparation and Analysis ........................................................ 64 Barcoding Sequence Analysis .......................................................................... 66 Incorporating Barcode Information into Diet ..................................................... 67 Results .................................................................................................................... 68 Discussion .............................................................................................................. 73 Potential Cannibalism ....................................................................................... 74 7 Trends in Diet with Unidentified Fish Resolved ...............................................