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File 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 Resources / Brook Trout Related Publications
File A regional neural network ensemble for predicting mean daily river water temperature
Water temperature is a fundamental property of river habitat and often a key aspect of river resource management, but measurements to characterize thermal regimes are not available for most streams and rivers. As such, we developed an artificial neural network (ANN) ensemble model to predict mean daily water temperature in 197,402 individual stream reaches during the warm season (May–October) throughout the native range of brook trout Salvelinus fontinalis in the eastern U.S. We compared four models with different groups of predictors to determine how well water temperature could be predicted by climatic, landform, and land cover attributes, and used the median prediction from an ensemble of 100 ANNs as our final prediction for each model. The final model included air temperature, landform attributes and forested land cover and predicted mean daily water temperatures with moderate accuracy as determined by root mean squared error (RMSE) at 886 training sites with data from 1980 to 2009 (RMSE = 1.91 C). Based on validation at 96 sites (RMSE = 1.82) and separately for data from 2010 (RMSE = 1.93), a year with relatively warmer conditions, the model was able to generalize to new stream reaches and years. The most important predictors were mean daily air temperature, prior 7 day mean air temperature, and network catchment area according to sensitivity analyses. Forest land cover at both riparian and catchment extents had relatively weak but clear negative effects. Predicted daily water temperature averaged for the month of July matched expected spatial trends with cooler temperatures in headwaters and at higher elevations and latitudes. Our ANN ensemble is unique in predicting daily temperatures throughout a large region, while other regional efforts have predicted at relatively coarse time steps. The model may prove a useful tool for predicting water temperatures in sampled and unsampled rivers under current conditions and future projections of climate and land use changes, thereby providing information that is valuable to management of river ecosystems and biota such as brook trout.
Located in Resources / Brook Trout Related Publications
File Octet Stream Removal of Two Dams in the Wetmore Run Watershed, PA_FY12 Project
As part of a plan to upgrade their public water supply to a non-dam alternative, the Borough of Galeton agreed to remove two dams and their associated impoundments. The dams were located on Wetmore Run and Right Branch of Wetmore Run, Potter County, PA. Both streams are classified as High Quality – Coldwater Fishery (HQ – CWF) by the Pennsylvania Department of Environmental Protection (PA DEP) and drain a predominantly forested watershed comprised of ~60% public land. The barriers blocked upstream Brook Trout passage to approximately 8.5 miles of headwater habitat, contributed to the elevation of instream temperatures, interrupted the natural flow regime, and negatively impacted ecosystem function. As a result of the dam removals, almost 8.5 miles of headwater habitat was reconnected to the rest of the upper Pine Creek Watershed, which contains several intact eastern Brook Trout populations.
Located in Projects / Project Completion Reports
File Description of Methods Used to Develop Brook Trout Conservation Priority Scores at the Subwatershed Scale - Hanson et al. 2014
This document describes the methodology used to develop priority scores for Brook Trout conservation at the subwatershed scale.
Located in Resources / Brook Trout Related Publications / Chesapeake Bay Brook Trout Management Strategy-References
File Final Report to EBTJV
Final Report to EBTJV
Located in Projects / 2011 Projects / Restoring Habitat Connectivity in Machias and Saint Croix River Tributary Streams, Maine
File Troff document Final Report
Final report to EBTJV
Located in Projects / 2011 Projects / Restoring Habitat Connectivity in Machias and Saint Croix River Tributary Streams, Maine
File 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 Resources / Brook Trout Related Publications / Chesapeake Bay Brook Trout Management Strategy-References
File 2014 MSCGP Grant Application
This document describes the full proposal seeking funding from the 2014 MSCGP.
Located in Resources / EBTJV Operational Grants / 2014 MSCGP Grant
File PS document 2014 MSCGP Grant Scope of Work for Eastern Fish Habitat Partnerships
This document describes the scope of work to be performed by the three Eastern FHPs (ACFHP, SARP, EBTJV) under the 2014 MSCGP grant.
Located in Resources / EBTJV Operational Grants / 2014 MSCGP Grant
File Troff document 2014 MSCGP Grant Performance Report
This document describes the grant-related accomplishments achieved during the 1/1/14 to 12/31/14 performance period.
Located in Resources / EBTJV Operational Grants / 2014 MSCGP Grant