Family-Level Benthic Macroinvertebrate Communities Indicate Successful Relocation and Restoration of a Northeast Iowa Stream

Abstract

A major stream relocation and restoration project was started in 2004 near Dorchester, Iowa. The project converted riparian cropland and stream bank trees to native tallgrass prairie vegetation while relocating Brook Creek to its original streambed. The goal of this project was to restore Brook Creek to conditions comparable with South Pine Creek, a nearby reference coldwater stream that was used as a model for Brook Creek. Benthic macroinvertebrates were monitored in 2005, 2007, 2010, and 2012 in both Brook Creek and South Pine Creek. Benthic macroinvertebrate family-level taxonomic richness, Ephemeroptera/Plecoptera/Trichoptera (EPT) family richness, and family-level biotic indices (FBI) were calculated. We found that Brook Creek’s FBI values were lowered and EPT richness values increased significantly from 2005 to 2012, indicating establishment of a high quality benthic macroinvertebrate community. Benthic macroinvertebrate communities in Brook Creek became increasingly similar to South Pine Creek over the course of this study as evidenced by a principle component analysis and percent similarity, from a 28.72% similarity in 2005 to 62.54% similarity in 2012. These results demonstrate the successful reestablishment of a benthic macroinvertebrate assemblage following stream reconstruction and similarity to a high-quality reference stream.