Perry, Stephen

Predicting Brook Trout Occurrence in Stream Reaches throughout their Native Range in the Eastern United States: The Brook Trout Salvelinus fontinalis is an important species of conservation concern in the eastern USA. We developed a model to predict Brook Trout population status within individual stream reaches throughout the species’ native range in the eastern USA. We utilized hierarchical logistic regression with Bayesian estimation to predict Brook Trout occurrence probability, and we allowed slopes and intercepts to vary among ecological drainage units (EDUs). Model performance was similar for 7,327 training samples and 1,832 validation samples based on the area under the receiver operating curve (»0.78) and Cohen’s kappa statistic (0.44). Predicted water temperature had a strong negative effect on Brook Trout occurrence probability at the stream reach scale and was also negatively associated with the EDU average probability of Brook Trout occurrence (i.e., EDU-specific intercepts). The effect of soil permeability was positive but decreased as EDU mean soil permeability increased. Brook Trout were less likely to occur in stream reaches surrounded by agricultural or developed land cover, and an interaction suggested that agricultural land cover also resulted in an increased sensitivity to water temperature. Our model provides a further understanding of how Brook Trout are shaped by habitat characteristics in the region and yields maps of stream-reach-scale predictions, which together can be used to support ongoing conservation and management efforts. These decision support tools can be used to identify the extent of potentially suitable habitat, estimate historic habitat losses, and prioritize conservation efforts by selecting suitable stream reaches for a given action. Future work could extend the model to account for additional landscape or habitat characteristics, include biotic interactions, or estimate potential Brook Trout responses to climate and land use changes.
Located in Science and Data / Brook Trout Related Publications
Probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty from maximum temperature metric selection: Predictions of the projected changes in species distribution models and potential adaptation action benefits can help guide conservation actions. There is substantial uncertainty in projecting species distributions into an unknown future, however, which can undermine confidence in predictions or misdirect conservation actions if not properly considered. Recent studies have shown that the selection of alternative climate metrics describing very different climatic aspects (e.g., mean air temperature vs. mean precipitation) can be a substantial source of projection uncertainty. It is unclear, however, how much projection uncertainty might stem from selecting among highly correlated, ecologically similar climate metrics (e.g., maximum temperature in July, maximum 30-day temperature) describing the same climatic aspect (e.g., maximum temperatures) that is known to limit a species’ distribution. It is also unclear how projection uncertainty might propagate into predictions of the potential benefits of adaptation actions that might lessen climate change effects. We provide probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty stemming from the selection of four maximum temperature metrics for brook trout (Salvelinus fontinalis), a cold-water salmonid of conservation concern in the eastern U.S. Projected losses in suitable stream length varied by as much as 20% among alternative maximum temperature metrics for mid-century climate projections, which was similar to variation among three climate models. Similarly, the regional average predicted increase in brook trout occurrence probability under an adaptation action scenario of full riparian forest restoration varied by as much as 0.2 among metrics. Our use of Bayesian inference provides probabilistic measures of vulnerability and adaptation action benefits for individual stream reaches that properly address statistical uncertainty and can help guide conservation actions. Our study demonstrates that even relatively small differences in the definitions of climate metrics can result in very different projections and reveal high uncertainty in predicted climate change effects.
Located in Science and Data / Brook Trout Related Publications
Project Completion Reports: This folder contains project completion reports that were submitted by the principal investigator(s) for those Brook Trout conservation projects that received EBTJV/FWS-NFHAP funding support.
Located in Projects
Project Sheet for Marsh Brook Road: Status report on the Marsh Brook Road project.
Located in Projects / … / 2013 Projects / Upper White River Habitat Restoration, VT
Project Sheet for Moose Run: Status report on the Moose Run project.
Located in Projects / … / 2013 Projects / Upper White River Habitat Restoration, VT
Project Sheet for North Hollow Road: Status report on the North Hollow Road project.
Located in Projects / … / 2013 Projects / Upper White River Habitat Restoration, VT
Project Sheet for Woodlawn Cemetery: Status report on the Woodlawn Cemetery project.
Located in Projects / … / 2013 Projects / Upper White River Habitat Restoration, VT
Quantifying the effect of semi-natural riparian cover on stream temperatures: implications for salmonid habitat management: Previous studies examining the effects of riparian cover on stream temperatures have led to highly variable findings. In an attempt to reduce these uncertainties, this study examines the relationship between stream temperature variability and local climatic conditions over discrete 300-m sections of a watercourse. Seventeen stream sections were chosen within the Slaney catchment on the basis of riparian cover and size. Continuous monitoring over a 2-year period from May 2010 found that riparian cover had a measurable cooling effect on water temperatures at small spatial scales. The magnitude of this effect was dependent on stream size and local climactic conditions.
Located in Science and Data / Brook Trout Related Publications
Ranking Site Vulnerability to Increasing Temperatures in Southern Appalachian Brook Trout Streams in VA: An Exposure-Sensitivity Approach - Trumbo et al. 2014: This publication describes an approach determining habitat vulnerability to climate change based on measures of sensitivity and exposure.
Located in Science and Data / Brook Trout Related Publications / Chesapeake Bay Brook Trout Management Strategy-References
Ranking Site Vulnerability to Increasing Temperatures in Southern Appalachian Brook Trout Streams in Virginia: An Exposure - Sensitivity Approach: Climate change vulnerability classification model for brook trout populations; brook trout populations are classified into one of four quadrants based on direct measurements or model predictions of sensitivity and exposure. Low exposure, low sensitivity populations are most likely to persist under various climate change scenarios.
Located in Science and Data / Brook Trout Related Publications

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