Date of Graduation

2017

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Forest Resource Management

Committee Chair

Jeffrey T Petty

Committee Co-Chair

Jeff L Hansbarger

Committee Member

Kyle Hartman

Abstract

Understanding the localized ecological impacts of large-scale environmental (i.e., land use and climate) change is of critical importance not only to scientists tasked with natural resource management, but also individuals and communities across the world. In the Appalachian Mountains of the eastern United States, Brook Trout Salvelinus fontinalis serve as a key indicator species for the integrity of stream habitats. Brook Trout populations have largely declined throughout their native range, with impending climate change and thermal habitat exclusion potentially reducing Brook Trout habitat by more than 50%. Therefore, it is imperative that we understand interactions between Brook Trout and the changing thermal landscape, as well as their responses to management projects designed to mitigate effects of land use and climate change. We conducted a telemetry study within Shavers Fork, West Virginia, to assess Brook and Brown Trout Salmo trutta response to restoration activities which were designed to create thermal refugia and improve Brook Trout habitat suitability in the main-stem channel while increasing fish access to previously severed tributary systems. The objectives of this study were to 1) quantify Brook and Brown Trout movement and habitat use throughout a high-elevation watershed consisting of a restored mainstem stream channel and reconnected tributaries, comparing these results to a pre-restoration study; and 2) determine association of native and exotic trout with restored habitat structures on the mainstem channel.;We implanted 51 Brook Trout and 13 Brown Trout with radio transmitters during two field seasons from June 1-3, 2015 (23 Brook Trout and 5 Brown Trout) and June 1-4, 2016 (28 Brook Trout and 8 Brown Trout) and tracked the movements of 38 Brook Trout and 11 Brown Trout through August 15, 2015 and 2016 On average, Brook Trout moved greater total distances from their tagging site (>3.00 km) than Brown Trout (<1 >km), in some cases moving over 4km in 24 hours. Brown Trout remained in the mainstem channel in all cases and associated with constructed habitat structures and natural pools. Analyses for relationships between Brook Trout and habitat structures show no verifiable response (X 2 =38.86, p = 0.651), while there does appear to be an association between Brown Trout and structure pools (X 2 = 14.24, p < 0.001). Net Dispersal analyses indicate a difference (t = 1.70, p = 0.02) in Brook Trout dispersal post versus pre-restoration. Comparisons of movement rates in Brook Trout using Kolmogorov-Smirnov tests also indicate a difference in rates of movement (meters/day) for Brook Trout from this study compared to those tagged in the pre-restoration survey (D = 0.35, p = 0.02). These results confirm the importance of connected, continuous fluvial systems with accessible coldwater habitat in facilitating Brook Trout dispersal and maintaining large-scale metapopulation structure. Our study suggests that native fish communities may benefit more from the removal of dispersal barriers than structural habitat improvement on mainstem rivers, and that structural improvements in larger mainstems may have the unintended consequence of benefiting exotic species to the detriment of native species.

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