Mapping the Movement of Marine Fishes: Methods, Mechanisms, and Implications for Invasion Management
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Mapping the Movement of Marine Fishes: Methods, Mechanisms, and Implications for Invasion Management by Natascia Laila Tamburello B.Sc., McGill University, 2007 Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Department of Biological Sciences Faculty of Science Natascia Laila Tamburello 2015 SIMON FRASER UNIVERSITY Fall 2015 Approval Name: Natascia Laila Tamburello Degree: Doctor of Philosophy (Biological Sciences) Title: Mapping the Movement of Marine Fishes: Methods, Mechanisms, and Implications for Invasion Management Examining Committee: Chair: Eirikur Palsson Assistant Professor Isabelle M. Côté Senior Supervisor Professor Nicholas K. Dulvy Supervisor Professor Wendy J. Palen Supervisor Associate Professor David J. Green Internal Examiner Professor Phillip Levin External Examiner Program Manager Ecosystem Science NOAA Fisheries Date Defended/Approved: September 21, 2015 ii Ethics Statement iii Abstract Movement represents a key ecological trait of individuals that has important implications for the spatial structuring of population, community, and ecosystem processes. However, the spatial ecology of terrestrial organisms is much better understood than that of their comparatively understudied aquatic counterparts. My thesis focuses on the methods and mechanisms underpinning the study of movement ecology in fishes, with special attention on the movement of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) on Caribbean coral reefs and its implications for invasion management. I begin by comparing broad-scale patterns of space use across all vertebrates, including fishes, to draw general conclusions about the factors driving their space requirements. My models reveal that body mass, locomotion strategy, foraging dimension, and trophic level predict ~80% of the variation in vertebrate home range size. I then describe a versatile method for GPS-based underwater mapping that will enable more routine collection of a wide variety of spatial data, including movement patterns, habitat characteristics, and bathymetry. This method is ideal for studies operating on smaller scales and budgets and will help advance the study of spatial ecology in aquatic environments. Next, I apply this mapping method to characterize the movements of tagged lionfish on Bahamian coral reefs, and find that lionfish movement is density dependent, declines at larger body sizes, and varies with seascape structure. Using these movement data, I model the metapopulation dynamics of lionfish in a patch reef network to show how removing lionfish from single patches influences metapopulation dynamics at the network scale, and show how landscape features that facilitate recolonization of cleared patches can negatively influence management outcomes. My thesis helps to fill critical gaps in our understanding of movement and space use of animals in general, and of marine fishes in particular. This work also demonstrates how a better understanding of movement ecology can help to optimize the distribution of limited resources for the management of marine invasive species, which represent a significant and growing threat to marine ecosystem biodiversity and function. Keywords: Spatial ecology; marine ecology; movement; home range; underwater mapping; invasive species. iv Acknowledgements Like the fishes I’ve followed, the path that led me here has been a long and winding one, and in my case, one with many people to thank along the way. First and foremost, thank you to my supervisory committee, Isabelle Côté, Nick Dulvy, and Wendy Palen, for all their guidance and support throughout the many twists and turns of this work. Isabelle, thank you for giving me the opportunity to study what I love, letting me follow research leads down the rabbit hole, encouraging me to stick with it through a Ph.D., and always inspiring me to be a better science communicator. Nick, you have always been a whirlwind of positive energy and good ideas – your ability to lend a fresh perspective, provide exactly the right obscure reference, and pull off pastels will never cease to amaze me. Wendy, thank you for guiding my first steps into the world of population modelling, I only wish we’d had more occasions to work together. Thanks also to David Green and Phil Levin for acting as the internal and external examiners, respectively, for my thesis. I could not have asked for a better setting in which to do research than the Earth to Ocean Research Group at SFU. Thank you all for helping me to think creatively about ecological problems, draw my inspiration from across disciplines, succumb to the siren song of R, and generally be a better scientist. I owe a special debt of gratitude to Stephanie Green and Holly Kindsvater in particular. Stephanie, thank you for giving me a crash course in surviving grad school, introducing me to my study system, and showing me how to trap, tag, spear, dissect, fillet, and, yes, even make ceviche out of my study species. Holly, you have been a friend, mentor, troubleshooter, therapist, and all-around inspiration, and I am forever grateful that you gave me a good reason to dust off my dive buoy, my drysuit, and my French. Thank you also to all the Côté lab members who welcomed me with open arms when I arrived bright-eyed and bushy tailed and kept me in good company during my time there: Stephanie Green, Emily Darling, Brett Favaro, Evan Henderson, Nicola Smith, Luis Malpica Cruz, Brett Howard, Fiona Francis, Adrienne Berchtold, and Lais Chaves. This project would not have been possible without my fearless field assistants. Molly Brewis, Chelsea Chisholm, and Nicola Smith, I cannot express how grateful I am for v your support in wrangling indignant lionfish, fending off hungry nurse sharks, weighing fish guts, hunting birthday lobster, keeping it classy in hurricane weather, and always getting me where I needed to be in the Mac Daddy, Mac Daddy, Mac Daddy. Your enduring friendship, along with the support of many other friends and loved ones, has helped stave off insanity through to the end. I am also indebted to all of the individuals and organizations that lent their support to this work. Thank you to all the scientists who graciously provided their data for synthesis – Douglas Kelt, Dirk Van Vuren, and Daniela Ottaviani for providing databases of mammal and bird home range sizes, Chris Carbone for providing a database of predator-prey mass ratios, and David Booth for providing unpublished data on fish length-weight relationships. I have truly stood on the shoulders of giants. Thank you also to all of the institutions that provided funding for this work in the form of an NSERC Canada Graduate Scholarship, a Michael Smith Foreign Study Supplement , an FQRNT Quebec Graduate Scholarship, a C.D. Nelson Memorial Graduate Entrance Scholarship, and a from Simon Fraser University Graduate Fellowship. Last but not least, thank you to all of the people who helped put me on this path. Alisa Dowling for teaching me to dive with military precision in the cold waters of the Pacific Northwest; Don Kramer for giving me my first taste of tropical field ecology and for nurturing the spark it touched off in me; Ian Popple for proving that marine biology is not just something people do on TV; and last but not least, thank you to my parents, Miki and Paolo for always indulging my childhood interest in the natural world, notwithstanding countless messy experiments, multiple municipal bylaw violations, and one escaped python. vi Table of Contents Approval .............................................................................................................................ii Ethics Statement ............................................................................................................... iii Abstract .............................................................................................................................iv Acknowledgements ........................................................................................................... v Table of Contents ............................................................................................................. vii List of Tables .....................................................................................................................ix List of Figures....................................................................................................................xi Introductory Image ...........................................................................................................xv Chapter 1. General Introduction ................................................................................. 1 Chapter 2. Energy and the scaling of animal space use ......................................... 4 2.1. Abstract .................................................................................................................... 4 2.2. Introduction .............................................................................................................. 5 2.3. Methods ................................................................................................................... 9 2.4. Results ................................................................................................................... 15 2.5. Discussion .............................................................................................................. 26 Chapter 3. Applications of diver-towed GPS mapping for aquatic spatial ecology