Failure of Reach-Scale Restoration to Improve Biotic Integrity in a Mid-Atlantic Stream

Reach-scale restoration to re-establish habitat integrity is practiced throughout the US. These techniques, while yielding aesthetic enhancement, may not result in ecological improvement. Using a before-after, control-impacted (BACI) sampling design, we evaluated the benthic macroinvertebrate community in two branches of the Codorus Creek, Southeastern PA throughout the course of restoration projects. Reach-scale restoration activities at several sites along both branches have been conducted since 2002. There was no significant change in the benthic macroinvertebrate community associated with reach-scale restoration. Even after the restoration projects were completed, downstream-impacted sites on both branches reflected severe stress with reduced numbers of organisms, low diversity, and impoverished pollution sensitive species. Thus, our results indicate that there were no significant short-term benefits resulting from reach-scale restoration. We recommend that the actions of individuals and organizations concerned with streams focus on watershed-scale conservation and restoration activities.