ABSTRACT: The effects of global warming trends on growth and food consumption rates for a brook trout Salvelinus fontinalis population were simulated with a bioenergetics model. We examined the hypothesis that improved growth conditions during cooler months will offset the opposing effects of extreme temperatures during the summer. Annual growth increments of brook trout were determined from a population in a high elevation stream in West Virginia, USA, and baseline stream temperatures were measured in mid to high elevation streams. The mean annual stream temperature was increased by 2 and 4*C to simulate the effects of climatic warming. Brook trout populations at high elevations in the Appalachian Mountains could either benefit from increased growth rates in spring and fall, or suffer from shrinking habitat and reduced growth rates in summer, depending on the magnitude of temperature change and on food availability. An increase of 2*C or less could very likely increase brook trout growth, but the effect of larger temperature increases is less predictable due to greater dependence on higher prey production. A 15 to 20% increase in food consumption would be required to maintain present rates of growth with an increase of 2*C, and 30 to 40% more food would be required with an increase of 4*C.

KEY WORDS: Brook trout . Bioenergetics model . Global warming . Temperature effects

Published in CR Vol. 5, No. 3 (1995) on December 7
ISSN: 0936-577X. Copyright © Inter-Research, Oldendorf/Luhe, 1995