FISH HABITAT AND FISH POPULATIONS IN A SOUTHERN APPALACHIAN WATERSHEDBEFORE AND AFTER HURRICANE HUGO

Habitat features and relative abundance of all fish species were estim ated in 8.4 km of a small mountain stream system before and 11 months after Hurricane Hugo crossed the southern Appalachians in September 19 89. There was no change in the total amount (area) of each habitat typ e but the total number of habitat units decreased and average size and depth of habitat units increased. Transport and sorting of streambed sediments was evident from the increased proportion of habitat units i n which cobbles and small boulders were the most common constituents. Large woody debris more than doubled from 228 to 559 pieces/km of stre am channel. At the watershed scale, there were only minor changes in t he fish community 11 months after the hurricane. Eleven species were f ound both before and after the storm, and most species were uncommon. Among common species, densities increased in riffles for darters Etheo stoma spp., increased in pools for blacknose dace Rhinichthys atratulu s, and were largely unaffected for rainbow trout Oncorhynchus mykiss. The results of this case study suggest that the effects of catastrophi c disturbances on fish habitat and populations depend on the predistur bance condition of instream and riparian habitat, timing of the distur bance, and life histories of individual species.