A Dissertation entitled Creating a Spatially-Explicit Habitat Suitability Index Model for Lake Sturgeon (Acipenser fulvescens) in the Maumee River, Ohio by Jessica J. Collier Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Biology (Ecology Track) _________________________________________ Jonathan M. Bossenbroek, PhD, Committee Chair _________________________________________ Christine M. Mayer, PhD, Committee Member _________________________________________ Todd Crail, PhD, Committee Member _________________________________________ Daryl M. Moorhead, PhD, Committee Member _________________________________________ Christopher S. Vandergoot, PhD, Committee Member _________________________________________ Amanda Bryant-Friedrich, PhD, Dean College of Graduate Studies The University of Toledo, May 2018 Copyright 2018, Jessica J Collier This document is copyrighted material. Under copyright law, no parts of this document may be reproduced without the expressed permission of the author. An Abstract of Creating a Spatially-Explicit Habitat Suitability Index Model for Multiple Life Stages of Lake Sturgeon (Acipenser fulvescens) in the Maumee River, Ohio by Jessica J. Collier Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Biology (Ecology Track) The University of Toledo May 2018 Biodiversity and ecological function are increasingly threatened by human impacts including fragmented systems, modified water and sediment flow, pollution, habitat degradation and alteration, overexploitation of species, and invasive species introduction. These impacts necessitate the need for conservation and restoration practices to protect natural resources and biodiversity. This dissertation outlines the development and implementation of habitat suitability index (HSI) models as tools to support species reintroduction efforts and monitor populations of imperiled species. Lake sturgeon (Acipenser fulvescens), a state listed species in Ohio, are a candidate for reintroduction in the Maumee River, Ohio, where they were historically abundant, but are now functionally extirpated. The goal of my dissertation was to determine if current habitat quantity and quality in the Maumee River are sufficient to support lake sturgeon reintroduction using habitat suitability index models for two important life stages: spawning adult and age-0 fish. The models I developed, using substrate, water velocity, and water depth, indicated that habitat quality, quantity, and connectivity for both spawning adult and age-0 lake sturgeon would support efforts to reintroduce this species. iii The results of these HSI models were used in the development of a reintroduction plan to summarize important elements for successful reintroduction efforts. The reintroduction plan provided a comprehensive outline incorporating biological, managerial, and societal perspectives, to identify potential barriers to lake sturgeon reintroduction and highlight direct actions to increase success. HSI models are valuable tools for reinforcing species restoration plans and improve conservation monitoring. After the development of the lake sturgeon HSI models for the Maumee River, I wanted to further investigate if the model structure and habitat data could be utilized for other species in the Maumee River. I tested model transferability on native unionid communities, a highly imperiled group of organisms, and found that the HSI model structure successfully predicted higher unionid abundances in habitats designated as high-quality, compared to marginal and unsuitable habitats. The models developed in this dissertation provide a tool for resource managers to evaluate restoration practices and monitor species populations which will help protect biodiversity and sustain our natural resources. iv This dissertation is dedicated to the amazing women in my life. Especially my mother, Dalyce, and my Aunt Chris. Your steadfast encouragement, support, reassurance, and love kept me going and made this dissertation a reality. I am so grateful to you. And to my husband, Chris, who brought me dinner on many late nights, listened to countless presentations, and wholly embraced my love for sturgeon. Thank you. I love you. v Acknowledgements The completion of this dissertation would not have been possible without support and help from the wonderful people in my life. First and foremost, I would like to thank my advisor, Dr. Jonathan Bossenbroek, for his encouragement, advice, and patience. He let me forge my own path while providing guidance and structure to keep me on track. A sincere thank you to my committee, Drs. Christine Mayer, Daryl Moorhead, Todd Crail, and Christopher Vandergoot, for their helpful insights and thoughtful challenges. I am deeply appreciative of Justin Chiotii and James Boase for their collaboration, support, and perspectives throughout this project. I would also like to express my gratitude and appreciation to the DES administrative assistants, Scott McBride & Dianne Mauter, who answered endless questions and were always quick to provide help. Further, I am so grateful to the many volunteers who provided field assistance and I owe a great deal of appreciation to my lab mates and friends who kept me going and shared endless laughs. A special thank you to Sara Guiher, Jake Kvistad, Deepesh Bista, and Kristen Hebebrand. To my husband, Chris, who was so steadfast in his encouragement, love, and patience – thank you for being there for me. Finally, thank you to my wonderful family, for always supporting and believing in me. To my grandparents, my Aunts & Uncles, and Steve – I owe you so much. Thank you to my mom, Dalyce, and my Aunt Chris, who have been my biggest supporters and taught me to believe in myself. vi Table of Contents Abstract .............................................................................................................................. iii Acknowledgements ............................................................................................................ vi Table of Contents .............................................................................................................. vii List of Tables .................................................................................................................... xi List of Figures ................................................................................................................... xii List of Abbreviations ....................................................................................................... xiv List of Symbols ..................................................................................................................xv 1 Introduction ..........................................................................................................1 1.1 Goals & Objectives ......................................................................................7 2 Assessing the Reintroduction of Lake Sturgeon (Acipenser fulvescens) to the Maumee River, Ohio using Habitat Suitability Index Models ................................9 2.1 Abstract ........................................................................................................9 2.2 Introduction ................................................................................................10 2.3 Methods......................................................................................................13 2.3.1 Site Description ..............................................................................13 2.3.2 Field Data Collection ....................................................................14 2.3.3 Model Development .......................................................................16 2.3.4 Sensitivity Analysis ......................................................................18 2.3.5 Habitat Connectivity .....................................................................19 vii 2.4 Results .......................................................................................................19 2.4.1 Spawning Adult HSI Model ..........................................................19 2.4.2 Age-0 HSI Model ..........................................................................20 2.4.3 Sensitivity Analysis ......................................................................21 2.4.4 Habitat Connectivity ......................................................................23 2.4.5 Relatedness of Habitat Variables ..................................................23 2.5 Discussion .................................................................................................24 2.5.1 Implications for Reintroduction .....................................................29 2.6 Acknowledgements ...................................................................................31 3 Maumee River Lake Sturgeon Reintroduction Plan ..............................................46 3.1 Executive Summary ...................................................................................46 3.2 Introduction ................................................................................................49 3.2.1 Biology and Historic Status of Lake Sturgeon in the Maumee River ...............................................................................................52 3.2.2 Assessing Lake Sturgeon Habitat in the Maumee River ..............54 3.2.2.1 Objective 1 .....................................................................54