An Ecological Approach to Management of an Important Reservoir Fishery
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An ecological approach to management of an important reservoir fishery DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Jahn Lee Kallis Graduate Program in Evolution, Ecology, and Organismal Biology The Ohio State University 2013 Dissertation Committee: Professor Elizabeth A. Marschall, Adviser Professor Stuart A. Ludsin Professor Roy A. Stein Copyright by Jahn Lee Kallis 2013 Abstract The research described herein was an attempt to determine the mechanisms underlying variation in success of saugeye (female Sander vitreus X male S. canadensis) stocked into Ohio reservoirs. In addition, we sought to identify the mechanisms that can be affected by management practices and provide a model framework for experimental assessments of fish stocking alternatives. We accomplished our goals using laboratory experiments and field assessments conducted at the individual and population levels. In a manipulative field study, we evaluated two fish management alternatives, stocking saugeye fry (approximately 6 mm total length (TL)) and stocking saugeye fingerlings (approximately 30 mm TL). We based our evaluation on a comprehensive analysis that included biological responses (i.e. saugeye growth and survival), economic criteria (i.e., saugeye production costs), and multiple fishery objectives. We also correlated saugeye growth and survival with environmental variables to help inform future stocking decisions. Although predation and the timing and abundance of larval gizzard shad prey have been implicated in the success of stocked saugeye cohorts, results from our field manipulative study did not strictly follow predictions from previous research. ii Thus, we combined saugeye historical data with data from our research to test earlier assumptions about saugeye predation mortality and the influence of gizzard shad on stocked saugeye cohorts. In separate study, we sought to link growth rate while fish were in the hatchery with survival in the reservoirs hypothesizing that knowing which traits were associated with high survival would give insights into the major sources of mortality. Finally, to determine if the first winter of life is an important recruitment bottleneck, we used laboratory and field studies to quantify first-winter effects, including indirect effects on growth and survival of stocked saugeye cohorts. The work described here addresses the limitations to recruitment and management in fish populations in general, but does so in the context of a reservoir-stocked piscivore whose survival is highly variable and poorly understood. We addressed basic questions about fish growth and survival during the first weeks of life, first growing season, and first winter. From an applied perspective we experimentally evaluated management alternatives and used our ecological findings to provide management recommendations. iii Acknowledgments I thank my adviser, Libby Marschall, for her continued support, counsel, and guidance through my doctoral program. Libby was instrumental in helping me find direction especially during the early parts of my research. She encouraged independence but went to great effort to make herself accessible. I also thank my committee members, Roy Stein and Stuart Ludsin, who provided valuable insights throughout this project and feedback on early drafts of this dissertation. The research described herein would not have been possible without the many people who assisted me in the field and laboratory. I thank former technicians Erich Williams, Brittany Gunther, and Michael Bahler and undergraduate researcher, Beth Dickey, who spent countless hours in the field and laboratory. I was fortunate to have such a team. I also thank the large number of people who assisted with fish tagging, a number that is far too long to list here. The Aquatic Ecology Lab has been a wonderful place to grow as a researcher. This dissertation and my own personal development was influenced by conversations with fellow graduate students, including Ruth Briland, Emily iv Burbacher, Paris Collingsworth, Thomas Evans, Troy Farmer, Brian Kinter, Cassandra May, Jeramy Pinkerton, Joseph Smith, Adam Thompson, and Jason Van Tassell. I am grateful to have overlapped with such a wonderful group of scientists let alone good people. Two Aquatic Ecology Lab post-docs, Joe Conroy and Kevin Pangle, were also influential. I especially thank Joe Conroy, who mentored me during the first year of this project. Barb Fate, Melissa Marburger, and Margarita Talavera helped me navigate technical issues and provided council on any number of subjects. This research was made possible by funding from the Ohio Department of Natural Resources, Division of Wildlife: Federal Aid in Sport Fish Restoration Project F-69-P, Fish Management in Ohio. This research also benefited through support from and interactions with personnel from the Ohio Division of Wildlife. I especially thank Scott Hale, Jon Sieber-Denlinger, and Rich Zweifel for their support and guidance. I also thank the large number of biologists who provided assistance in the field. Finally, I thank my family for their endless support and inspiration. Most of all, I thank my wife, Erica, who was always a source of love and encouragement. v Vita January 1978 .......................................... Born - Yakima, Washington 2000 ....................................................... B.S. Biology, Whitworth College 2005 ...................................................... M.S. Environmental Science, Western Washington University 2007 to present ...................................... Graduate Research Associate, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University Publications Kallis, J.L., L. Bodensteiner, and A. Gabriel. Hydrological controls and freshening in meromictic Soap Lake, Washington, 1939-2001. Journal of the American Water Resources Association. 46:744-756 Fields of study Major Field: Evolution, Ecology, and Organismal Biology vi Table of Contents Abstract .................................................................................................................ii Acknowledgments ................................................................................................iv Vita .......................................................................................................................vi List of Tables ...................................................................................................... viii List of Figures .......................................................................................................xi 1. Introduction ............................................................................................. 1 2. How body size and food availability influences first-winter growth and survival of a stocked piscivore ......................................................... 7 Introduction ..................................................................................... 7 Methods ........................................................................................ 10 Results .......................................................................................... 16 Discussion ..................................................................................... 19 3. How size at stocking, reservoir conditions, and fishery objectives influence success of a reservoir-stocked piscivore ............................... 32 Introduction ................................................................................... 32 Methods ........................................................................................ 35 Results .......................................................................................... 42 Discussion ..................................................................................... 47 4. Explaining variable survival of a reservoir-stocked piscivore using retrospective analyses .......................................................................... 69 Introduction ................................................................................... 69 Methods ........................................................................................ 72 Results .......................................................................................... 81 Discussion ..................................................................................... 84 5. Does growth during the first weeks of life explain survival of a reservoir-stocked piscivore? ................................................................. 99 Introduction ................................................................................... 99 Methods ...................................................................................... 101 Results ........................................................................................ 103 Discussion ................................................................................... 103 Literature Cited ................................................................................................. 112 vii List of Tables Table 1. Characteristics of Ohio reservoirs from which age-0 saugeye were collected for energy density estimation during fall and spring. The mean chlorophyll-a concentration was the grand mean of outflow sites collected once per month (April - October) during 2007 – 2011. .............................................................................. 26