Perry, Stephen

The Importance of Scale: Assessing and Predicting Brook Trout Status - Hudy et al. 2013: This article analyzes extensive fine-scale occupancy data across the southern historic range of Brook Trout.
Located in Science and Data / Brook Trout Related Publications / Chesapeake Bay Brook Trout Management Strategy-References
The Importance of Scale: Assessing and Predicting Brook Trout Status in its Southern Native Range: Occupancy models are of increasing interest to managers and natural resource decision makers. Assessment of status and trends, as well as the specific drivers influencing occupancy, both may change as a function of scale, and analyses conducted at multiple scales can help identify important mechanisms leading to changes in distributions. We analyzed extensive fine-scale occupancy data across the southern historic range of the brook trout, Salvelinus fontinalis to determine which landscape metrics and thresholds were useful in predicting brook trout presence across three relevant spatial scales and how brook trout occupancy varied by scale. Percentage occupancy declined markedly with increased spatial resolution, as 52% of watersheds (HUC10) but only 32% of subwatersheds (HUC12) and 14% of catchments (HUC14) were occupied. Across all three scales, habitats which were exclusively occupied by native brook trout (without non-native trout) were rare (<10%). CART models using GIS-derived landscape predictor variables were developed for three classification cases: Case 1:(brook trout; no brook trout), Case 2 (brook trout; non-native trout only; no trout), and Case 3 (brook trout only; brook and non-native trout; non-native trout only and no trout). Model results were sensitive to both scale and the number of classification categories with respect to classification accuracy, variable selection and variable threshold values. Classification accuracy tended to be lowest at the finest (catchment) scale potentially reflecting stochastic population processes and barriers to movement. Classification rates for the overall models were: Case 1: Watershed (80.19%); Subwatershed (85.06%); Catchment (71.13%); Case 2: Watershed (69.31%); Subwatershed (68.72%); Catchment (57.38%); Case 3: Watershed (58.91%); Subwatershed (59.83%); Catchment (47.59%). Our multiscale approach revealed soil permeability (positive) and atmospheric pollution (negative) to be important predictors. The predicted occupancy and observed status of brook trout appear to be influenced by the scale the data are collected and reported.
Located in Science and Data / Brook Trout Related Publications
The influence of land cover composition and groundwater on thermal habitat availability for brook trout populations: Brook charr (Salvelinus fontinalis) is a sentinel fish species that requires clean, cold water habitats generally resulting from landscapes that allow for surface water flows devoid of sediment and contaminants and high groundwater discharge of cold water. As such, brook charr are impacted by land cover changes that alter stream temperature regimes. We evaluated brook charr populations across their eastern and midwestern range in the United States with reference to thermal habitat availability in relationship to land cover and percent baseflow. We found that while forest cover does protect brook charr thermal habitat, high levels of groundwater discharge can allow for increased levels of agriculture within a watershed by keeping the water cold in spite of warm ambient summer temperatures. Our study concludes that with enhanced communication among land, water and fisheries managers, society can provide for sustainable stream salmonid populations despite increased threats on cold water resources.
Located in Science and Data / Brook Trout Related Publications
The temperature–productivity squeeze: constraints on brook trout growth along an Appalachian river continuum: We tested the hypothesis that brook trout growth rates are controlled by a complex interaction of food availability, water temperature, and competitor density. We quantified trout diet, growth, and consumption in small headwater tributaries characterized as cold with low food and high trout density, larger tributaries characterized as cold with moderate food and moderate trout density, and large main stems characterized as warm with high food and low trout density. Brook trout consumption was highest in the main stem where diets shifted from insects in headwaters to fishes and crayfish in larger streams. Despite highwater temperatures, trout growth rates also were consistently highest in the main stem, likely due to competitively dominant trout monopolizing thermal refugia. Temporal changes in trout density had a direct negative effect on brook trout growth rates. Our results suggest that competition for food constrains brook trout growth in small streams, but access to thermal refugia in productive main stem habitats enables dominant trout to supplement growth at a watershed scale. Brook trout conservation in this region should seek to relieve the ‘‘temperature–productivity squeeze,’’ whereby brook trout productivity is constrained by access to habitats that provide both suitable water temperature and sufficient prey.
Located in Science and Data / Brook Trout Related Publications
The use of environmental (eDNA) to inform fish eradication efforts to restore native aquatic species.: 30 minute webinar
Located in The Story of Wild Brook Trout / Brook Trout Video and Webinar Gallery
Tipton Creek Culvert Replacement, NC_FY10 Project: In the summer of 2011 the culvert at the Davis Creek Road (FSR 420) crossing of Tipton Creek was removed and replaced with a concrete arch, stream simulation crossing for the purpose of passing aquatic organisms, where the existing culvert was known to be a barrier to aquatic passage due to velocity and outlet drop. The crossing was sized using the 100-year flow calculation derived from the USGS Regression Equation for the mountains of North Carolina. Additionally, the width of the crossing was designed to accommodate a bankfull flow channel dimension plus a small area of floodplain. The channel was reconstructed through the crossing using the dimension, pattern, and profile of the reference reach upstream. The new channel was constructed using imported boulders and onsite alluvial materials. Grass seed was sown, and trees and shrubs were planted, both potted and live-stakes. Over the last year since construction, the site has experienced several small flood events. The site remains stable, passable to all aquatic species, and looks more and more natural every year as planted and natural vegetation establishes.
Located in Projects / Project Completion Reports
TU Eastern Brook Trout Conservation Portfolio, Range-wide Assessment and Focal Area Tools: Trout Unlimited developed three conservation planning products to help identify strategic conservation opportunities and evaluate potential projects within the range of Eastern Brook Trout (EBT) in the eastern US.
Located in Science and Data / Data and Brook Trout Decision Support Tools
Understanding environmental DNA detection probabilities: A case study using a stream-dwelling char Salvelinus fontinalis: Environmental DNA sampling (eDNA) has emerged as a powerful tool for detecting aquatic animals. Previous research suggests that eDNA methods are substantially more sensitive than traditional sampling. However, the factors influencing eDNA detection and the resulting sampling costs are still not well understood. Here we use multiple experiments to derive independent estimates of eDNA production rates and downstream persistence from brook trout (Salvelinus fontinalis) in streams. We use these estimates to parameterize models comparing the false negative detection rates of eDNA sampling and traditional backpack electrofishing. We find that using the protocols in this study eDNA had reasonable detection probabilities at extremely low animal densities (e.g., probability of detection 0.18 at densities of one fish per stream kilometer) and very high detection probabilities at population-level densities (e.g., probability of detection N0.99 at densities of ≥3 fish per 100 m). This is substantially more sensitive than traditional electrofishing for determining the presence of brook trout and may translate into important cost savings when animals are rare. Our findings are consistent with a growing body of literature showing that eDNA sampling is a powerful tool for the detection of aquatic species, particularly those that are rare and difficult to sample using traditional methods.
Located in Science and Data / Brook Trout Related Publications
Upper Shavers Fork Instream and Riparian Habitat Restoration: Project application
Located in Projects / … / 2015 Projects / Upper Shavers Fork Instream and Riparian Habitat Restoration, Randolph County, WV
Upper South Branch/Thorn Creek Brook Trout Patch Restoration and Monitoring, Cave, WV: This project will restore habitat to a degraded three mile section of Thorn Creek in support of strengthening the Thorn Creek Brook Trout Patch, and expand that patch into the South Branch of the Potomac. The project cost is $270,250 and the estimated socioeconomic benefit is $1.6 million.
Located in Projects / 2006 - 2018 Projects / 2018 Projects

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