Changes in Standing Crop of Brook Trout Concurrent with Removal of Exotic Trout Species, Great Smoky Mountains National Park

摘要

Exotic rainbow trout (Salmo gairdneri) and brown trout (Salmo trutta) were removed by electrofishing from sympatric populations containing native brook trout (Salvelinus fontinalis) in remote headwater stream study areas in Great Smoky Mountains National Park. Exotic trouts were removed each year and brook trout were marked and returned to the areas from which they were captured. As exotic species were removed from sympatric populations, brook trout populations responded markedly, showing increases in numbers and total weights as reflected by standing crops of each sympatric population. In 1978, the standing crop of only one sympatric population had increased to surpass the numerical value present at the beginning of this investigation in 1976.