Harmful Algal Blooms in Small Lakes: Causes, Health Risks, and Novel Exposure Prevention Strategies Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Igor Mrdjen, B.S. Graduate Program in Public Health The Ohio State University 2018 Dissertation Committee Jiyoung Lee, Advisor Christopher M. Weghorst C.K. Shum Qinghua Sun 1 Copyrighted by Igor Mrdjen 2018 2 Abstract The increasing frequency and severity of harmful algal blooms (HABs) has quickly become an environmental health concern worldwide. As rates of anthropogenic nutrient use rise with growing food demand, and as extreme precipitation events are expected to increase with the changing climate, rates of nutrient influx into watersheds are expected to increase. With increasing nutrient loads and temperatures in watersheds, many of the world’s water bodies and reservoirs are becoming eutrophic, establishing optimal conditions for HAB formation. HABs may change the ecology of water bodies; produce hypoxic zones resulting in fish deaths; and produce cyanotoxin compounds toxic to the liver, nervous system, and reproductive system of most eukaryotic organisms. Human and animal exposure to the most commonly occurring cyanotoxin, microcystin (MC), has been linked with hepatotoxicity, nausea, vomiting, and death in extreme circumstances. Within the MC family of toxins, microcystin-LR (MC-LR) is the most common, possesses the highest toxicity, and is cited as a suspected carcinogen. While HAB mitigation and MC exposure prevention efforts have often focused on large lakes and bodies of water, small lakes and ponds (SLaPs) remain understudied and unmonitored. SLaPs are the most numerous lentic bodies of water worldwide, providing vital ecosystem services and biodiversity support. Due to their location, low volume, and seasonal water level changes, SLaPs are at an increased risk for eutrophication and HAB formation. SLaPs have many uses including recreation, aquaculture, irrigation, and even drinking water sources in ii economically stressed areas of the world. The utility of SLaPs presents a potential exposure pathway to HABs and MC compounds. While our knowledge base of MC-related health outcomes continues to grow, several gaps exist, including: low dose, chronic exposure outcomes; differences in toxicity between pure toxic compounds and crude cyanobacterial extracts; and the cancer promoting role of MCs. Finally, current satellite-based remote sensing methods demonstrate several limitations in the study and monitoring of HAB formation in SLaPs, including: land adjacency effect contamination, prohibitive costs, and inadequate spatial and temporal resolutions. The overall goal of this work is to address the existing knowledge gaps pertaining to HAB appearance in SLaPs, MC toxicity from chronic and acute exposures, and to improve the current monitoring methods. Chapter 1 reviews the current knowledge base of HABs and cyanobacteria, the production of toxins, and the mechanisms of MC toxicity and potential mechanisms of cancer promotion. Various cyanobacterial genera were discussed in terms of different types of cyanotoxin production. Contributions of environmental triggers of cyanotoxin production are described and detailed. Chapter 2 explores the impacts of anthropogenic land use and nutrient runoff on HABs in 24 SLaPs in central Ohio. Statistical analyses showed several relationships connecting anthropogenic land use to increased nutrient concentrations in sampled SLaPs. In one of those 24 lakes, the impact of tile drainage was explored. Changes in prokaryotic and eukaryotic communities, HAB occurrence, and high MC concentrations were noted. Chapter 3 and Chapter 4 focus on the potential health outcomes in acute and chronic exposure scenarios, respectively, using mice. Chapter 3 explores the changes in pathological, iii clinical chemistry, and gap junction intercellular communication (GJIC) attributed to acute MC- LR exposures. Male and female CD-1 mice exposed to MC-LR via oral gavage were evaluated for measures of changes in liver health. Findings show increased MC-LR toxicity in female mice compared to males, and show that GJIC does not play a prominent role in MC-LR toxicity under the experimental condition. Similarly, Chapter 4 explores chronic exposure to 10 µg/L MC-LR and a crude M. aeruginosa Lysate in a two-stage mouse model of cancer promotion. Mice were initiated with a known carcinogen, and administered MC-LR or cyanobacterial Lysate via ad libitum drinking water consumption. Results show increased toxicity of cyanobacterial Lysate and the potential promotion of liver cancer by MC compounds. Chapter 5 summarizes a proof-of-concept of a novel approach to HAB monitoring in near-shore lake environments based on remote sensing technologies. An unmanned aerial vehicle (UAV) equipped with multispectral cameras was deployed for remote sensing of near-shore areas of Lake Erie and Buckeye Lake. Image derived Normalized Difference Vegetation Index (NDVI) values were compared to lab analyzed water samples. The feasibility of UAV-based remote sensing is discussed and solutions to future implementations are proposed. iv Dedication This work is dedicated to my family, friends, and mentors, who have invested a great deal of time and energy to allow me the opportunity to follow my passions. v Acknowledgments This work would not have been possible without the guidance of my advisor and lab- mates, support of my mentors, and the help of my family and friends. I would like to acknowledge the incredible contributions of my advisor Dr. Jiyoung Lee. Her patience, support and guidance were invaluable during my time at The Ohio State University (OSU). Dr. Lee is an incredible advisor and role model who ensured a professional, friendly, and educational environment in lab and in the classroom. Additionally, I would like to thank my past and current peers & lab-mates: Seungjun Lee, Lindsay Collart, Tyler Gorham, Claire Bollinger, Alba Mayta, Manjunath Manubolu, Chenlin Hu, Xuewen Jiang, Alina Yang, Yuehan Ai, Yuanyuan Jia, and Matt McCrink. The training, experience and friendships they provided were essential to my development. I am forever grateful for the support and patience provided to by my committee and various collaborators during my studies at OSU. I would personally like to thank Dr. Christopher M. Weghorst for his wiliness to mentor me and introduce me to areas of research which were previously unknown to me. Special thanks also go out to my collaborators Dr. C.K. Shum, Dr. Jim Gregory, Dr. Kellie Archer, Dr. Michael Pennell, Dr. Mark Morse, and Dr. Randall J. Ruch, for all of their contributions toward my education and the completion of my research. I wish to thank Dr. Michael Bisesi and Dr. Amy Ferketich for mentoring me and supporting me in my development as an instructor. I would also like to acknowledge Dr. Thomas J. Knobloch, who vi was there at every step of the way to offer guidance, advice, friendly conversation, and much- needed coffee breaks. Finally, special thanks go to my parents, who sacrificed everything imaginable to provide me with the opportunity at a great education and the chance to follow my dreams. Their love and support will forever be welcomed. Finally, I would like to thank my brother and friends for always pushing me to succeed and providing an outlet for the stress that comes with ambition. vii Vita 2010................................................................Normandy High School 2014................................................................B.S. Biology Baldwin Wallace University 2014 to present ...............................................Graduate Program in Public Health Specialization: Environmental Health Sciences The Ohio State University Publications Mrdjen, I, Fennessy, S, Schaal, A, Slonchzewski, J, Lee, J. Tile Drainage and Anthropogenic Land Use Contribute to Harmful Algal Blooms and Microbiota Shifts in Inland Water Bodies, Environmental Science and Technology, 2018, in press. Mrdjen, I. & Lee, J. Simple and Practical On-Site Treatment of High Microcystin Levels in Water Using Polypropylene Plastic for Protection of Human, Animal, and Ecosystem Health, Journal of Environmental Science and Health Part A, (2018) in press. Mrdjen, I & Lee, J. High volume hydraulic fracturing operations: potential impacts on surface water and human health, International Journal of Environmental Health Research, 2016: 26:4, 361-380, DOI: 10.1080/09603123.2015.1111314 viii Field of Study Major Field: Public Health ix Table of Contents Abstract ........................................................................................................................................... ii Dedication ....................................................................................................................................... v Acknowledgments.......................................................................................................................... vi Vita ............................................................................................................................................... viii List of Tables ............................................................................................................................... xiv List of Figures ............................................................................................................................... xv Chapter 1. Introduction ..................................................................................................................