Examination and Characterization of Brook Trout Ecology Before and After a Broad Scale Disturbance Event in Headwater Streams of West Virginia, USA

Abstract

The Appalachian Mountains have experienced comprehensive human disturbance since the colonial period. Activities such as mining, logging, and development for agriculture and residential lands have changed the landscape from the old growth state of centuries past. These disturbances have also led to changes in the forests and their drainage systems over time. Native species like the Brook Trout Salvelinus fontinalis have experienced declines in both size and abundance due to changes in their headwater stream habitats as a function of human activities. Restoration of these habitats by both state and federal agencies, as well as non-government organizations, has been occurring following the destructive logging of the late nineteenth and early twentieth centuries. In many places, a return to the conditions found in the old-growth state would take hundreds or even thousands of years, but restoration efforts have shown promise in accelerating the recovery of these native ecosystems. Restoration efforts may focus on chemical, physical, or biological endpoints. Within these headwater streams, a lack of physical channel structure in the form of deep pools and large wood has been shown to limit Brook Trout growth and reproduction. Therefore, many times restoration teams will focus on rebuilding habitat complexity through the physical construction of pools or addition of large wood pieces that may aid in providing fish cover and sediment/organic matter retention. These artificial habitat supplements have been studied by others and have shown some successes in benefitting habitat conditions. However, less is known about natural disturbances that may represent additional stream habitat benefits. Brook Trout populations of headwater streams in West Virginia, USA, and the effects of one such natural disturbance are the focus of the following chapters. Hurricane Sandy, otherwise known as "superstorm" or "frankenstorm" Sandy was the largest (by area) Atlantic hurricane on record in the United States. It struck the eastern continental United States in late October/early November 2012 and combined with a traditional winter nor'easter storm across the mid-Atlantic. This combination of storms produced record snowfall in much of the Appalachian Mountains, with snow accumulations over three feet (0.9 meters) in just a 24 hour period. The snowfall was very wet and dense, and resulted in widespread tree collapse in many forested areas. Some of those trees were deposited in headwater streams that coincided with study sites for a 15+ year study of stream habitat and Brook Trout populations conducted at West Virginia University. The objectives of this work were numerous and were to first quantify the amount and extent of large wood deposition within the set of headwater streams used in the long-term study. The second objective was to identify and explain some Brook Trout population dynamics across throughout the process of this dissertation work. First, thanks to Dr. Kyle Hartman as my graduate advisor and as the chair of my academic commit...

Genetic predictors of population resilience: A case study of native Brook Trout in headwater streams

“…In our study streams, Brook Trout populations have been observed to experience >60% reductions in abundance due to environmental factors such as drought disturbance (Hakala and Hartman 2004). Some populations within our study systems have been observed to respond to disturbances differently than what is observed in the majority of the streams due primarily to demographic and habitat factors (Andrew 2018). Since Brook Trout populations, including our study populations, fluctuate naturally, the N e of our populations may be largely driven by long‐term stability and gene flow rather than short‐term stability.…”