Potential effects of global climate warming on brook trout growth and prey consumption in central Appalachian streams, USA

Abstract

The effects of global warmlng 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 w ~ l l 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 Virg~nia, USA, and basehne stream temperatures were measured in mid to high elevation streams. The mean annual stream temperature was increased by 2 and 4°C to smula t e the effects of climatic warming. Brook trout populations at h ~ g h elevations In the Appalachian Mountains could either benefit from increased growth rates in sprlng and fall, or suffer from shnnklng habitat and reduced growth rates in summer, d e p e n d ~ n g 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 bigher prey produc!ion P. 15 to 2 0 % increase in focd ccns~rnnt inn r----wcc!d he r-ni-d --I-**-!G maintain present rates of growth with an increase of 2C, and 30 to 40% more food would be required with an increase of 4°C.