Fall and Early Winter Movement and Habitat Use of Wild Brook Trout
Abstract
Brook Trout Salvelinus fontinalis populations face a myriad of threats throughout the species’ native range in
the eastern United States. Understanding wild Brook Trout movement patterns and habitat requirements is essential
for conserving existing populations and for restoring habitats that no longer support self-sustaining populations.
To address uncertainties related to wild Brook Trout movements and habitat use, we radio-tracked 36 fish in a
headwater stream system in central Pennsylvania during the fall and early winter of 2010–2011. We used generalized
additive mixed models and discrete choice models with random effects to evaluate seasonal movement and habitat
use, respectively. There was variability among fish in movement patterns; however, most of the movement was
associated with the onset of the spawning season and was positively correlated with fish size and stream flow. There
was heterogeneity among fish in selection of intermediate (0.26–0.44 m deep) and deep (0.44–1.06 m deep) residual
pools, while all Brook Trout showed similar selection for shallow (0.10–0.26 m) residual pools. There was selection for
shallow residual pools during the spawning season, followed by selection for deep residual pools as winter approached.
Brook Trout demonstrated a threshold effect for habitat selection with respect to pool length, and selection for pools
increased as average pool length increased up to approximately 30 m, and then use declined rapidly for pool habitats
greater than 30 m in length. The heterogeneity and nonlinear dynamics of movement and habitat use of wild Brook
Trout observed in this study underscores two important points: (1) linear models may not always provide an accurate
description of movement and habitat use, which can have implications for management, and (2) maintaining stream
connectivity and habitat heterogeneity is important when managing self-sustaining Brook Trout populations.
Publication Date: 2014
Credits: R. Mollenhauer et al.,
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