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Wild Brook Trout (Salvelinus fontinalis) Demographics and Movement in the Presence of Undersized Road Crossings in Headwater Streams in Central New Hampshire By Tyson R. Morrill B.S. Fisheries & Wildlife Science: Wildlife Concentration, Paul Smith’s College, 2014 A THESIS Submitted to Plymouth State University In partial fulfilment of the requirements for the degree of Master of Science in Biology Defended July 22, 2019 Degree Conferred August 1, 2019 AN ABSTRACT OF THE THESIS OF Tyson R. Morrill for the degree of Master of Science in Biology presented on July 22, 2019 Title: Impacts of Historic Barriers on Wild Brook Trout (Salvelinus fontinalis) in Central New Hampshire Abstract approved: _______________________________ Brigid C. O’Donnell, Ph.D. Populations of wild Brook Trout (Salvelinus fontinalis) continue to decline across their historic range, making relatively healthy populations and intact habitats within northern New England increasingly important for conservation. The Beebe River watershed, located in central New Hampshire, is home to intact headwater populations of wild Brook Trout despite movement barriers and riparian manipulation affecting tributaries to the mainstem river. The region has also experienced two centuries of widespread timber harvest and a century of stream acidification, creating further ecological stressors. We focused on three headwater tributaries with 1) impassable road crossing and reduced canopy cover, 2) passable road crossing and reduced canopy cover, and 3) no impediments to movement and unaltered canopy. We documented Brook Trout abundance, density, age structure, condition, biomass, growth, net movement, cumulative movement, home range, and recruitment with the goal of better understanding potential habitat influences on fish across tributaries and among geomorphic threshold regions. Our primary sampling methods included depletion electrofishing, PIT tag mark-recapture techniques, and detailed habitat assessments and temperature monitoring. We hypothesized that undersized crossings and no-low canopy reaches would create physical and thermal barriers for fish. In particular, we predicted that fish in streams with these barriers would exhibit lower density, fewer age classes and lower growth rates while seasonal and annual movement would increase compared to fish in an unimpacted stream. Overall, tributary populations were comprised of young fish that exhibited little movement. We failed to support many of our hypothesis metrics due to underestimating the indirect influences of no-low canopy reaches. Although we documented a crossing barrier inhibiting upstream movement, fish with unrestricted access to the no-low canopy primarily grew more and moved less, while density remained stable interannually. In contrast, fish in the most impacted stream and the unimpacted stream exhibited increased movement and significant declines in interannual density. This project was a unique opportunity to compile a detailed description of the spatial and temporal differences in Brook trout populations for two seasons prior to multiple crossing replacements and habitat enhancement. Our research helps fisheries managers to better understand the benefit of watershed-wide restoration to inform the protection of wild Brook Trout populations. © Copyright by Tyson R. Morrill July 30, 2019 All Rights Reserved Master of Science thesis of Tyson R. Morrill presented on July 22, 2019 APPROVED: _________________________________________ Co-Major Professor Brigid C. O’Donnell, Ph.D. Associate Professor of Integrative Biology, Plymouth State University Department of Biological Sciences _________________________________________ Co-Major Professor Amy M. Villamagna, Ph.D. Associate Professor of Conservation Ecology, Plymouth State University Department of Environmental Science & Policy, Center for the Environment _________________________________________ Leonard R. Reitsma, Ph.D. Professor of Zoology, Plymouth State University Department of Biological Sciences I understand that my thesis will become part of the permanent collection of Plymouth State University, Lamson Library. My signature below authorizes release of my thesis to any reader upon request. _________________________________________ Tyson R. Morrill, Author ACKNOWLEDGEMENTS This study was part of a larger project intended to improve water quality, connectivity, aquatic habitat and improve degraded infrastructure across the majority of a watershed. I am thankful to become involved in such an expansive project, driven by diverse partners with a moral desire to ensure our natural resources persist for future generations. I thank everyone who’s primary goal was large-scale restoration, but accepted our ongoing research during project planning and ongoing construction, including The Conservation Fund, NH Fish and Game Department, the Towns of Campton and Sandwich, NH, Trout Unlimited: Pemigewasset Chapter and New England Culvert Project, Tin Mountain Conservation Center, Squam Lake Conservation Society, NH Department of Environmental Services, USDA Forest Service, US Natural Resources Conservation Service and local contractors. Our work could not have been possible without the trust of the landowner, Nancy Bell and her vision of preserving vulnerable natural resources. I would like to thank Ben Nugent for his tireless support intellectually and in the field. His passion for fisheries is inspiring to myself and anyone he interacts with. Our project could not have been accomplished to the scale I envisioned without the dozens of Trout Unlimited volunteers. Their long days of shuttling buckets of fish and passion for wild trout keep the spirt alive. I am thankful for financial support by Plymouth State University through the Joe and Gail White Graduate Fellowship, Student Research Advisory Council (SRAC) and tuition assistance, The Conservation Fund and Trout Unlimited: Pemigewasset Chapter. Furthermore, I am appreciative for Plymouth State University by providing the opportunity to teach. It defined my unrecognized desire to advocate for the natural world by educating others. I would like to thank Dr. Len Reitsma for his critical yet thoughtful feedback on my writing and project as a whole. His expertise as a naturalist is a critical skill that I strive to gain as a future scientist. I sincerely appreciate the devotion and persistence of Dr. Brigid O’Donnell and Dr. Amy Villamagna over the last three years, beginning with taking the risk of accepting a skunk trapper to establish a fish project. Their grounded inspiration helped me grow as a researcher, even as I tested their patience. I will forever attribute my future career success to the opportunity they provided me. Finally I would like to thank my family and friends. They understood how difficult it was for someone who lives for the outdoors to spend days on end behind a computer, but they knew how important this degree was for me. And to my parents- I promise I will move out soon, again. CONTRIBUTION OF AUTHORS Dr. Brigid O’Donnell assisted in project study design, led acquisition and use of sampling and monitoring equipment, provided intellectual expertise, thesis revisions, and overall guidance. Dr. Amy Villamagna assisted in project study design, led acquisition and use of sampling and monitoring equipment, provided intellectual expertise, thesis revisions, and overall guidance. Ben Nugent assisted in project study design, provided sampling and monitoring equipment, co-led field sampling, provided specialized intellectual expertise, and was the primary NH Fish & Game Department liaison. i ACKNOWLEDGEMENTS This study was part of a larger project intended to improve water quality, connectivity, aquatic habitat and improve degraded infrastructure across the majority of a watershed. I am thankful to become involved in such an expansive project, driven by diverse partners with a moral desire to ensure our natural resources persist for future generations. I thank everyone who’s primary goal was large-scale restoration, but accepted our ongoing research during project planning and ongoing construction, including The Conservation Fund, NH Fish and Game Department, the Towns of Campton and Sandwich, NH, Trout Unlimited: Pemigewasset Chapter and New England Culvert Project, Tin Mountain Conservation Center, Squam Lake Conservation Society, NH Department of Environmental Services, USDA Forest Service, US Natural Resources Conservation Service and local contractors. Our work could not have been possible without the trust of the landowner, Nancy Bell and her vision of preserving vulnerable natural resources. I would like to thank Ben Nugent for his tireless support intellectually and in the field. His passion for fisheries is inspiring to myself and anyone he interacts with. Our project could not have been accomplished to the scale I envisioned without the dozens of Trout Unlimited volunteers. Their long days of shuttling buckets of fish and passion for wild trout keep the spirt alive. I am thankful for financial support by Plymouth State University through the Joe and Gail White Graduate Fellowship, Student Research Advisory Council (SRAC) and tuition assistance, The Conservation Fund and Trout Unlimited: Pemigewasset Chapter. Furthermore, I am appreciative for Plymouth State University by providing the opportunity to teach. It defined my unrecognized desire to advocate for the natural world by educating others. I would like to thank Dr. Len Reitsma for his critical yet thoughtful feedback on my writing and project

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