ABSTRACT IMPACT OF VESSEL NOISE ON OYSTER TOADFISH (OPSANUS TAU) BEHAVIOR AND IMPLICATIONS FOR UNDERWATER NOISE MANAGEMENT By Cecilia S. Krahforst April 2017 Director of Dissertation: Joseph J. Luczkovich, Ph.D. Major Department: Coastal Resources Management ABSTRACT Underwater noise and its impacts on marine life are growing management concerns. This dissertation considers both the ecological and social concerns of underwater noise, using the oyster toadfish (Opsanus tau) as a model species. Oyster toadfish call for mates using a boatwhistle sound, but increased ambient noise levels from vessels or other anthropogenic activities are likely to influence the ability of males to find mates. If increased ambient noise levels reduce fish fitness then underwater noise can impact socially valued ecosystem services (e.g. fisheries). The following ecological objectives of the impacts of underwater noise on oyster toadfish were investigated: (1) to determine how noise influences male calling behavior; (2) to assess how areas of high vessel activity (“noisy”) and low vessel activity (“quiet”) influence habitat utilization (fish standard length and occupancy rate); and (3) to discover if fitness (number of clutches and number of embryos per clutch) is lower in “noisy” compared with “quiet” sites. Field experiments were executed in “noisy” and “quiet” areas. Recorded calls by males in response to playback sounds (vessel, predator, and snapping shrimp sounds) and egg deposition by females (“noisy” vs. “quiet” sites) demonstrated that oyster toadfish are impacted by underwater noise. First, males decreased their call rates and called louder in response to increased ambient noise levels. Second, oyster toadfish selected nesting sites in areas with little or no inboard motorboat activity. Third, male oyster toadfish at “noisy” sites either had no egg clutches on their shelters or the number of embryos per clutch was significantly lower than in the “quiet” areas. Underwater noise and disturbance from vessels are influencing the fitness of the oyster toadfish. The social significance of the growing concerns regarding underwater noise was investigated by identifying dominant themes found within two types of texts: four recent underwater noise management strategy papers and 14 texts from the federal enabling legislation. To uncover themes that might reveal underlying cultural patterns and values, word frequency of key terms in each set of documents was compared using a correspondence analysis and network analyses. The predominant theme within the noise management documents was "assessing the acoustic impacts and protecting marine life [esp. marine mammals]." The legislative documents spanned a range of concerns but focused primarily on themes associated with the trade-offs between human use and the environment, such as resource "conservation" and "development." In terms of marine life, the enabling federal legislation used “fish” and the noise management documents focused on “marine mammals” as their primary animal of concern. This disparity between document types explained the paucity of ecosystem services that were discussed in the noise management documents because fish and fisheries provide important ecosystem services to the human population. By focusing more on the concept of fish, the noise management documents would be more effective at incorporating ecosystem services, which is likely to be more socially accepted than the current management initiatives. IMPACT OF VESSEL NOISE ON OYSTER TOADFISH (OPSANUS TAU) BEHAVIOR AND IMPLICATIONS FOR UNDERWATER NOISE MANAGEMENT A Dissertation Presented to the Faculty of The Institute for Coastal Science and Policy, Coastal Resources Management East Carolina University In Partial Fulfillment of the Requirements for the Degree of Ph.D. in Coastal Resources Management Primary Concentration in Coastal & Estuarine Ecology Secondary Concentration in Social Science & Coastal Policy By Cecilia S. Krahforst April 2017 © Copyright 2017 Cecilia S. Krahforst IMPACT OF VESSEL NOISE ON OYSTER TOADFISH (OPSANUS TAU) BEHAVIOR AND IMPLICATIONS FOR UNDERWATER NOISE MANAGEMENT By Cecilia S. Krahforst DISSERTATION DIRECTOR: ____________________________________________ (Joseph J. Luczkovich, Ph.D.) COMMITTEE MEMBER: ____________________________________________ (Mark W. Sprague, Ph.D.) COMMITTEE MEMBER: ____________________________________________ (Michael L. Fine, Ph.D.) COMMITTEE MEMBER: ____________________________________________ (David K. Loomis, Ph.D.) COMMITTEE MEMBER: ____________________________________________ (Jeffrey C. Johnson, Ph.D.) DIRECTOR OF COASTAL RESOURCES MANAGEMENT: ____________________________________________ (Siddhartha Mitra, Ph.D.) DEAN OF THE GRADUATE SCHOOL: ____________________________________________ (Paul J. Gemperline, Ph.D.) DEDICATION This work is dedicated to those who never stopped believing in me. Especially: Dr. Roger A. Rulifson & My Family & Friends Words cannot express my thanks. The future belongs to those who believe in the beauty of their dreams. -Eleanor Roosevelt ACKNOWLEDGEMENTS There are many people that I need to thank for their assistance through this process. These individuals include my committee members, ECU faculty and staff, research support received from institutions outside of ECU, undergraduate assistants, volunteers, family, friends, and funding sources for this work. Your support and assistance made this work possible. First, Dr. Joseph J. Luczkovich was there through everything. Thank you for your support, encouragement, mentoring, and guidance through this process. I know there was rarely an easy day but I want you to know that I really appreciate everything that you have done for me. Thank you for allowing me to question and debate concepts with you every step of the way. This step was imperative to my learning process and my ability to improve as a scientist. I would especially like to express my gratitude to you for allowing me to follow my interests and explore concepts that I thought were valuable, even though funding was extremely difficult. Going forward, I hope that you can be proud of the scientist that you had a hand in creating. To my biologic/acoustic committee members, I hope you both know just how important and valuable your input was to me during this dissertation process. Dr. Mark W. Sprague, I relied heavily on your expertise in acoustics. I acknowledge your assistance, understanding, and patience regarding my acoustics-related questions. Thank you for your gentle encouragement and guidance and helping me to obtain some of the tools I need to move forward in the bioacoustics world. Dr. Michael L. Fine, thank you so much for your everyday enthusiasm and excitement over even the little things. Your little notes of encouragement or brief and often comical check-in e-mails brightened my day. I felt like I was talking to a friend and for that, I cannot thank you enough. I am in your debt for your encouragement to read outside of my discipline and to look beyond ecology and into the area of physiology to help answer some of my questions. Thank you so much for your unwavering support and encouragement. My social science committee members served such different roles but yet, they both worked to open my eyes to something new, social science, a concept that I have struggled with from the start of this dissertation. Dr. David K. Loomis worked hard at finding ways to identify with my biological mindset. All of the papers and books would never have changed my mind but your willingness to sit and chat with me helped to move me to better understand social values and their role(s) in management. I will never forget our discussions nor the coy way that you would drop a social term (procedural justice, distributive justice, norms, etc) into the conversation. These types of remarks, slowly helped me to understand the value of these concepts in everyday life, and thus their value to management. Without your persistence and patience, I do not think I would have made the connection. Dr. Jeffrey C. Johnson was an important member of my work from the start. When others told me that my work was not valuable you very pointedly disagreed with them, giving me hope that others would come to value my interests. As I was writing my proposal, you offered many dynamic points of view that led me to explore other areas of interest. At the end, it was so much fun to put our worlds together in a network analysis. Our conversations on the concept were enlightening and helped me to better understand the value of the data we had explored. Thank you for your encouragement, your advice, your guidance, and your willingness to stand-up for me when others argued against my work. Three CRM directors have been very supportive of me and my work. First, Dr. Lauriston R. King encouraged me to explore the politics associated with management decisions. His courses opened me up to a new world, where politics defines management decisions and thus what is protected and utilized in the environment. I realize now just how in-touch Dr. King was about the direction of management. When I started the CRM program, underwater noise problems were just beginning to be acknowledged. He told me back then to just wait, that the field of bioacoustics was soon to become important within the social framework. He couldn’t have been more accurate because in 2016 there was a management initiative written to address the concerns of underwater noise. Thank you, Dr. King, for your encouragement and excitement about the work I had yet to start. Second, I really appreciate Dr. Hans Vogelsong for his support and assistance. When funding was difficult for me to conduct my initial dissertation research, Dr. Vogelsong came up with funding for me to execute the work. Because of his support, I was able to obtain preliminary data that we were able to use to get a grant. He also was extremely supportive of me and knew when to step in and offer his encouragement and support. Thank you, Dr. Vogelsong, for being there for me, as a director and a friend. Finally, Dr. Siddhartha Mitra has been a person I have been able to lean on for support and advice. I know that I can talk to Dr.
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