Portland State University PDXScholar Dissertations and Theses Dissertations and Theses Summer 8-10-2017 Anthropogenic Effects on the Fouling Community: Impacts of Biological Invasions and Anthropogenic Structures on Community Structure Whitney Elizabeth McClees Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Environmental Sciences Commons, and the Marine Biology Commons Let us know how access to this document benefits ou.y Recommended Citation McClees, Whitney Elizabeth, "Anthropogenic Effects on the Fouling Community: Impacts of Biological Invasions and Anthropogenic Structures on Community Structure" (2017). Dissertations and Theses. Paper 3883. https://doi.org/10.15760/etd.5771 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Anthropogenic Effects on the Fouling Community: Impacts of Biological Invasions and Anthropogenic Structures on Community Structure by Whitney Elizabeth McClees A thesis submitted in partial fulfillment of the requirements of the degree of Master of Science in Environmental Science and Management Thesis Committee: Catherine de Rivera, Chair Sarah Eppley Gregory Ruiz Portland State University 2017 © 2017 Whitney Elizabeth McClees Abstract Coastal anthropogenic infrastructure has significantly modified nearshore environments. Because these structures often have a strong association with shipping as would be found in ports and harbors, they have been identified as invasion hotspots. Due to propagule pressure from shipping and recreational boating and suitable uncolonized substrate that provides a refuge from native predators, a greater number of non-native species have been found on these structures compared to nearby natural substrate. The mechanisms that limit the spread of non-native species from anthropogenic structures to natural substrate have been explored for several taxa at a species-specific level, but less so from an overall community perspective. Predation has been identified as one of the biotic interactions limiting invasion success. In addition to predation, dispersal ability may also prevent the spread of non-native species from anthropogenic structures to natural substrate. This thesis addresses how these two mechanisms interact to limit the spread of non-native species from anthropogenic structures to natural substrate and how that alters overall community composition. I aimed to explore differences between communities inside and outside of a marina and determine the extent to which predator and dispersal limitation were structuring these communities. I used a three-factor design, deploying seven unglazed ceramic tiles per each treatment combination of 1) in versus outside a marina in Yaquina Bay, Oregon; 2) cage keeping out predators greater than the mesh size, no cage, or partial cage; 3) fixed near the substrata (benthic) versus suspended 1 meter below the surface. I also transplanted caged, suspended tiles of either adults or recruits from inside the marina to benthic and suspended caging treatments outside of the i marina. These tiles allowed me to examine predation when dispersal limitation was not a factor for the community inside the marina, i.e. what happens to both recruits and adults if they can get outside of the marina. I found that the communities inside and outside of the marina were different and the data suggest that both predation and dispersal limitation interact to limit the spread of non-native species. Additionally, I found that mesopredators that could fit through the caging may be influencing predation results and community structure. This research addresses gaps in scientific knowledge regarding the mechanisms that prevent or facilitate the spread of non-native species. Future work could include the further exploration of mesopredation as an important factor in limiting the spread of non- native species and exploring dispersal limitation more in depth as well as broadening the geographic scope to see if the same trends hold true across bays and bioregions. ii Acknowledgements I would first like to thank my advisor, Dr. Cat de Rivera. I would not have made it this far without her support, guidance, reassurance, and unfailing good humor. I would also like to extend my thanks to my committee members, Drs. Greg Ruiz and Sarah Eppley, for their guidance and input throughout this process. This research would not have been possible without funding from the NSF Cascades to Coast GK-12 Program, the GK-12 Mini-Grant, and two Edward D. and Olive C. Bushby Scholarships. Thank you to the Embarcadero Marina in Newport, especially the dock master Matt Williams, for being such generous hosts to my research by providing me with boats to use, allowing me to store equipment on site, and permitting me to hammer nails into their docks. Along a similar vein, thanks to Hatfield Marine Science Center for providing me with lab and tank space and a few of their summer interns to help with my research. To everyone who assisted me with this work, I could not have done it without you: Corinne Heath, Roxanne Valencia, Yen Vu, Hayley Hinrichs, Chase Spearing, Gabriel Court, Alissa Harrison, Jessica Schutt, John Zalusky, Sebastien Eichvalds, Inez Lawson, Amy Ehrhart, Alex Drinkard, Kazia Mermel, Olivia Blondheim, and anyone else I am forgetting. A big thank you to my de Rivera lab mates who helped in the lab, in the field, provided constructive criticism, experimental design input, and many, many laughs. I would also like to extend heartfelt thanks to the staff of the Environmental Science and Management Department at Portland State University, especially to Sherie Huffman for helping me stay sane while navigating all the appropriate paperwork. Thank iii you to Jim Carlton for starting me on this crazy fouling journey and for letting me send him barnacle bits in the mail for identification. A huge thank you to my family and friends who have supported me through this whole journey. Thank you to my parents, Jock and Carol; without your support and guidance, I would not be where I am today (and thanks, Dad, for passing along your bio nerd genes). To my sister, Cameron: thank you for enduring field and lab work when you came to visit; I promise I won’t steal your vacation again. And finally, a huge thank you to my partner, Stephanie, whose unflappable and unfailing love and support have been an integral part of this whole process. She has been my copy editor, my sounding board, my captive defense audience, my shoulder to cry one, but above all, she has been my love. iv Table of Contents Abstract ................................................................................................................................ i Acknowledgements ............................................................................................................ iii List of Tables ..................................................................................................................... vi List of Figures .................................................................................................................. viii Chapter 1: Introduction ....................................................................................................... 1 1.1 Biological Invasions ................................................................................................. 1 1.2 Marine Biological Invasions ..................................................................................... 2 1.3 The Fouling Community and Biological Invasions .................................................. 5 1.4 Effect of Flow and Dispersal on Recruitment .......................................................... 6 1.5 Predation and Biotic Resistance in Fouling Communities ....................................... 9 Chapter 2: The limitation of spread of non-native marine invertebrates from anthropogenic structures to natural habitats ..................................................................... 13 Introduction ................................................................................................................... 13 Methods ........................................................................................................................ 18 Study Site .................................................................................................................. 18 Field Sampling .......................................................................................................... 19 Laboratory Data Collection....................................................................................... 23 Data Analysis ............................................................................................................ 24 Results ........................................................................................................................... 30 Does Community Characterization Change Across Location and Depth? ............... 30 Does Dispersal Play a Role in Structuring Fouling Communities and Contribute to Limiting the Spread of Non-Native Species? ........................................................... 32 Does Predation Play a Role in Structuring Fouling Communities and Contribute to Limiting the Spread of Non-Native Species? ........................................................... 34 Discussion