Post‐Defaunation Recovery of Fish Assemblages in Southeastern Blackwater Streams

We analyzed fish assemblage structure at 37 sites in South Carolina streams before and nearly one year after experimental defaunation to test assemblage resiliency. Decreases in stream depth and width in the second year reflected an intervening drought, but habitat structure remained highly correlated between years. Fish assemblages recovered well over four scales of analysis. Total fishes sampled, collective assemblage properties (species richness, density, biomass, and mean mass of fish), local assemblage structure, and single—species attributes generally did not significantly differ after defaunation, as determined by species— and individual—abundance correlations, detrended correspondence analysis, and a proportional similarity index. These assemblages were not randomly structured units, but were largely deterministic systems highly predictable from local habitat structure.