Predicting trout population and fish assemblage responses to reduced riprian [sic] buffer widths in northern Georgia, USA

The Georgia State Legislature reduced the mandatory riparian buffer width along Georgias trout streams from 30 to 15 m. This research evaluated the responses of trout populations and fish assemblages to this buffer width reduction. With a 15-m buffer, stream temperatures will increase by 1.6 to 2.3 C and fine sediment in riffles will increase by 11%, resulting in an over 80% reduction in the biomass of young-of-the-year trout. With a 15-m buffer, 91% of the trout stream network would be too warm (> 21.5 C) to support reproducing trout populations. As stream temperatures increase, range-restricted and benthic spawning fishes will decline. Substantial warming of trout streams has occurred along the trout stream network because of existing riparian deforestation. Further deforestation of riparian areas, which is allowed with the 15-m buffer width, will contribute to the thermal warming of trout streams and, thereby, jeopardize their capacity to support trout and native Southeastern fishes.