Hydrobiologia

, Volume 727, Issue 1, pp 151–166

The temperature–productivity squeeze: constraints on brook trout growth along an Appalachian river continuum

  • J. Todd Petty
  • David Thorne
  • Brock M. Huntsman
  • Patricia M. Mazik
Primary Research Paper

Abstract

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 high water 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.

Keywords

Brook trout Growth and consumption Diet Watershed scale Density dependence Competition Thermal refugia 

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • J. Todd Petty
    • 1
  • David Thorne
    • 1
    • 3
  • Brock M. Huntsman
    • 1
  • Patricia M. Mazik
    • 2
  1. 1.Division of Forestry and Natural ResourcesWest Virginia UniversityMorgantownUSA
  2. 2.U.S. Geological Survey, WV Cooperative Fish and Wildlife Research UnitWest Virginia UniversityMorgantownUSA
  3. 3.West Virginia Division of Natural ResourcesElkinsUSA

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