Author ORCID Identifier

https://orcid.org/0009-0003-1243-6709

Semester

Summer

Date of Graduation

2025

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Division of Forestry and Natural Resources

Committee Chair

Kyle Hartman

Committee Member

Brent Murry

Committee Member

David Thorne

Abstract

Projects which monitor long-term trends in ecosystems are uncommon but extremely important in the management of fish and wildlife populations. By assessing the health of a population or community over multiple temporal scales, these projects provide true insight into population success that cannot be elucidated through short-term studies. Long-term projects are also instrumental in assessing the effects of disturbance events as they provide valuable baseline information which can be compared to data collected post-disturbance. Even more importantly, long-term studies can help identify crucial changes in the health and success of imperiled and invaluable species to improve and focus conservation efforts.

One such species, the Brook Trout, Salvelinus fontinalis, was the focus of this thesis. In the central Appalachians, few fish are as beloved or as important, economically and ecologically, as the Brook Trout. The only stream trout native to the eastern United States, Brook Trout are desirable and iconic target for anglers. The species is also a top predator in headwater stream ecosystems and impacts the biotic community at multiple levels. However, anthropogenic disturbance over the past century has resulted in significant declines in the abundance and distribution of Brook Trout across their range. To conserve the species, managers must have accurate information regarding the long-term health of Brook Trout populations and the ways in which those populations vary across the landscape. In fisheries management, metrics like abundance and biomass are often used to evaluate population success in this way; however, other metrics are available which may be able to measure the health of Brook Trout populations more accurately.

Secondary production, the biomass produced in an area over time, is a useful but underutilized metric for the evaluation of fish populations. As it is a rate, it naturally encompasses temporal changes in population health better than static metrics like abundance. However, as each production estimate requires multiple sampling events and detailed information about cohort size, production is rarely calculated by agencies or used to make management decisions. As such, typical Brook Trout production estimates and the factors that might affect production in the region are unknown. Likewise, prior to this thesis study, it was not yet known whether the broad decline in Brook Trout abundance documented throughout their range had impacted Brook Trout production in headwater central Appalachian streams. Therefore, the overarching aim of this thesis was to evaluate changes in Brook Trout production over the past two decades and in response to various changes in their environment. To do this I used data collected as part of a long-term Brook Trout monitoring project which began in 2003. This project encompassed 25 headwater Brook Trout streams in east-central West Virginia which were sampled annually to quantify their biotic community and the availability and quality of fish habitat. The breadth of this long-term monitoring project, both spatially and temporally, provided unique insight into the spatial and temporal variability that Brook Trout populations in the region experience.

In my first chapter, I aimed to fill current knowledge gaps by quantifying annual Brook Trout production in the 25 study sites monitored annually and in two additional larger sites which also contained Brook Trout. Then, I used environmental data collected as part of the longterm project or collected by other agencies also monitoring the study sites to determine what factors were driving variability in Brook Trout production over time and across the landscape. Mean annual Brook Trout production in the study sites was 0.920 g/m2 /yr, much lower than many other published estimates of salmonid production and indicative of low overall productivity in the study sites. I also detected significant declines in Brook Trout production over time, driven primarily by changes in summer precipitation and increased Beaver Castor canadensis activity. Spatial variability in production was primarily driven by surficial geology, though additional factors like elevation, canopy cover, and habitat played a role.

The second chapter of this thesis focused on the response of Brook Trout populations and instream habitat to a significant disturbance event. Superstorm Sandy, a major Atlantic hurricane, struck the study sites in October of 2012, midway through the monitoring project. A previous study on the impact of superstorm Sandy found significant increases in large wood (LW) loads in the study sites immediately following the storm. I examined long-term trends in LW loads and Brook Trout production in the study sites based on the magnitude of those impacts and found no long-term difference in either parameter when comparing streams significantly impacted by Sandy and those hardly touched. However, I also identified a slight but significant decline in LW loads in the study sites over the past two decades, possibly driven by historic changes to the riparian forest from widespread logging in the early 20th century. These results serve as valuable baseline data for the conservation of Brook Trout in central Appalachia and highlight the value of long-term monitoring projects. Without two decades of relevant data, the trends in fish populations and their habitat I detected would have been difficult, if not impossible, to identify. Moving forward, other studies evaluating the production of Brook Trout or other species present in the region will have comparable literature to reference. Conservation efforts can now be focused on those streams and populations most at risk of habitat loss and population decline.

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