Brook trout use of thermal refugia and foraging habitat influenced by brown trout

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

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Abstract

The distribution of native brook trout (Salvelinus fontinalis) in eastern North America is often limited by temperature and introduced brown trout (Salmo trutta), the relative importance of which is poorly understood but critical for conservation and restoration planning. We evaluated effects of brown trout on brook trout behavior and habitat use in experimental streams across increasing temperatures (14–23 °C) with simulated groundwater upwelling zones providing thermal refugia (6–9 °C below ambient temperatures). Allopatric and sympatric trout populations increased their use of upwelling zones as ambient temperatures increased, demonstrating the importance of groundwater as thermal refugia in warming streams. Allopatric brook trout showed greater movement rates and more even spatial distributions within streams than sympatric brook trout, suggesting interference competition by brown trout for access to forage habitats located outside thermal refugia. Our results indicate that removal of introduced brown trout may facilitate native brook trout expansion and population viability in downstream reaches depending in part on the spatial configuration of groundwater upwelling zones.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Brook trout use of thermal refugia and foraging habitat influenced by brown trout
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/cjfas-2016-0255
Volume 74
Issue 3
Year Published 2017
Language English
Publisher NRC Research Press
Contributing office(s) Leetown Science Center
Description 13 p.
First page 406
Last page 418