CALIFORNIA STATE UNIVERSITY, NORTHRIDGE Initial Indicators Of

CALIFORNIA STATE UNIVERSITY, NORTHRIDGE Initial indicators of MPA success and factors that contribute to MPA efficacy A thesis submitted in partial fulfillment of the requirements For the degree of Master of Science in Biology By Erin M. Jaco December 2018 The thesis of Erin M. Jaco is approved: _________________________________________ __________________ Dr. Robert Carpenter Date _________________________________________ __________________ Dr. Larry Allen Date _________________________________________ __________________ Dr. Mark Steele, Chair Date ii ACKNOWLEDGEMENTS First and foremost I would like to thank my advisor, Dr. Mark Steele. Mark helped me in so many ways throughout the development and execution of my thesis research. By some how keeping me sane when I started getting lost down data and calculus rabbit holes, reminding me to keep the big picture in perspective, correcting my stacked modifiers, and trusting an Oregon driver to trailer his boat through Los Angeles traffic, Mark shaped me to be a better writer and scientist. I want to thank him for his mentorship and friendship. I would also like to thank the other two members of my thesis committee: Dr. Larry Allen and Dr. Robert Carpenter. Both Larry and Bob had invaluable insight into the development of my project. I really appreciate all of the comments and revisions that they contributed to my thesis. A huge thanks to everyone who helped with my field work: James French, Sigfrido Zimmermann, Lindsey Stockton, Hannah Nelson, Melissa Kurman, Juan Enciso, Zoë Scott, Dan Sternberg, Russell Dauksis, Kathryn Scafidi, George Jarvis, Erika Nava, Griffin Srednick, Alexis Estrada, Dorothy Horn, and Ashtyn Isaak. I cannot express how grateful I am to these positive and hardworking people who, paid only in kettle chips and gummy worms, put up with hours of tank hauling, early mornings, L.A. traffic, wildfires, seasickness and many long, cold dives. Thank you for the support from my fellow CSUN grad students who accompanied me on many adventures. From getting lost in the Sierras to celebrating at the Bunker, my time at CSUN has meant so much more to me than a degree because of the amazing people that I have gotten to know. To call out a few: Melissa, you always stood by me, iii even through trailering situations that still give me nightmares; Hannah, you pushed me to be a stronger scientist and you never let me take the easy way out both when it came to my research and to our adventures; Sigfrido, thank you for providing stress relief in the form of disc golf, Mario Kart, and backpacking. I have had so much support from all of my friends and family scattered around the world. A huge thank you to my parents, Stan and Kathy Jaco, who always pushed me to be independent and hardworking and who never waivered in their encouragement of my goals. And finally, thank you to all of the members of the Steele lab, both past and present. Working with my lab mates have been some of my favorite times in grad school, from car karaoke to Frisbee breaks to late nights in the lab. Many of you listened to my research ideas and helped turn my ramblings into coherent thoughts with direction. I feel lucky to have found myself a part of this goofy, supportive, slightly dysfunctional, and hardworking group of people. iv TABLE OF CONTENTS SIGNATURE PAGE ................................................................................................................. II ACKNOWLEDGEMENTS ...................................................................................................... III ABSTRACT ............................................................................................................................. VI CHAPTER 1: INTRODUCTION ................................................................................................ 1 CHAPTER 2: USING STEREO-VIDEO TO ASSESS INITIAL RESPONSES OF FISH TO PROTECTION IN RECENTLY ESTABLISHED MPAS ........................................................... 5 INTRODUCTION: ...................................................................................................................... 5 METHODS ............................................................................................................................... 8 RESULTS ............................................................................................................................... 15 DISCUSSION .......................................................................................................................... 18 CHAPTER 3: EFFECTS OF MPAS ON TARGETED FISHES ARE GREATER IN AREAS OF HIGH EXPLOITATION ........................................................................................................... 33 INTRODUCTION ..................................................................................................................... 33 METHODS: ............................................................................................................................ 38 RESULTS: .............................................................................................................................. 46 DISCUSSION: ......................................................................................................................... 50 CHAPTER 4: CONCLUSION .................................................................................................. 75 WORKS CITED ....................................................................................................................... 77 v ABSTRACT INITIAL INDICATORS OF MPA SUCCESS AND FACTORS THAT CONTRIBUTE TO MPA EFFICACY By Erin M. Jaco Master of Science in Biology Fishing is one of the most destructive anthropogenic forces in the marine environment. As the number of overfished stocks increases there is a greater need for effective management. Marine Protected Areas (MPAs) can be successful tools in combating the effects of overfishing by creating no-take zones that protect entire ecosystems. Despite evidence of the positive effects of MPAs, such as increases in abundance, biomass, and body size of targeted organisms, the magnitude of the effects of MPAs can vary dramatically. This study examined heterogeneity in the effects of MPAs on fishes to determine how quickly effects develop, if there is variation in detectability of MPA effects among biological metrics, and if heterogeneity in the responses of fishes to MPA protection can be predicted by historical fishing pressure. Using a diver operated stereo-video camera system, I compared assemblages of fishes targeted by anglers within seven MPAs to nearby comparison areas (non-MPAs) within the Southern California Bight. The differences of body size, biomass, and density of fishes between MPAs and non-MPAs were evaluated to determine which metrics showed detectable MPA effects after 5 years of protection. The size-based indicators, body sizes and biomass, showed the strongest responses to protection. There was, however, high regional variation in the degree of responses among MPAs. Some of this regional variation was explained by historical fishing pressure. By using fine-scale fishing pressure quantified within each MPA prior to protection, I was able to test responses of fishes to protection along a vi gradient of exploitation. MPAs in areas with heavy historical fishing pressure had greater responses in average lengths and size distributions of targeted species than did those in areas with low fishing pressure. Because many stakeholders are invested in marine resources, there is strong societal pressure for accurate predictions of MPA outcomes. The biological metric used to evaluate MPAs must be considered when predicting the magnitude and speed of responses within MPAs. Additionally, historical fishing pressure influences the efficacy of MPAs, and prioritizing heavily exploited areas for protection when implementing MPAs could maximize ecological outcomes. vii CHAPTER 1: INTRODUCTION As human populations increase, so has the number of overfished populations, with more than 33% of the world’s fish stocks classified as overfished (FAO, 2018). Although humans have fished for thousands of years, increased demand, due to human population growth combined with technological advances, has resulted in fishing becoming increasingly destructive (Pauly et al., 2000; Jackson et al. 2001). Most extraction by humans involves selective harvesting, where individuals with certain desirable traits are removed. Frequently, individuals are selected based on body size, with fishers most often selecting for the largest, most profitable individuals within a population (Fenberg and Roy, 2008). Overfishing and size-selective harvesting can negatively affect populations by reducing abundances, altering life history traits (e.g., age at maturation), and decreasing the average body size of targeted organisms (Conover et al., 2009). Ecosystem-based management has become a commonly used strategy among resource managers, due to its capacity to protect entire ecosystems rather than individual species. In the marine realm, ecosystem-based management is primarily done through the implementation of marine protected areas (MPAs). This protection can ultimately increase abundances and sizes of targeted species in fished areas outside of MPAs via adult migration (da Silva et al., 2015) and larval dispersal (Christie et al., 2010). Despite extensive documentation on the positive effects of MPAs on ecosystems (Lubchenco et al., 2003), not all MPAs are equally effective, and predicting

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