Fry, Benjamin, Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA, 17701, bjfry174@yahoo.com; Kaunert, Matt, , Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA, 17701, kaunert@lycoming.edu; Rieck, Leslie, Clean Water Institute Lycoming College 1 College Place Williamsport PA, 17701, rieck@lycoming.edu.
The Lycoming Biology Field Station (LBFS) is a 116 acre subsidized property owned by Lycoming College adjacent to Loyalsock Creek north of Montoursville, PA. In 2011, Tropical Storm Lee caused historic flooding in Loyalsock Creek resulting in the formation of an avulsion channel that now bisects the LBFS property. Increased bank degradation, nutrient/sediment loading, and damage to local properties led LBFS and USFWS to propose extensive stream restoration efforts to redirect stream flow to the historic channel to improve downstream water quality and prevent future erosion. In this study, we evaluated variation in macroinvertebrate community composition (macroinvertebrate density, Shannon diversity, Hilsenhoff Biotic Index, and EPT taxa) between the historic and avulsion channel as well as sites upstream of the restoration site to provide control data. We collected macroinvertebrates using three 90-s Surber samples in riffle habitat and three 60-s Kick-nets in run/pool habitats stratified across the stream width at each site. We compared indices across channel types using linear models. We found no significant differences in Shannon diversity index (F_1,16= 3.66, p = 0.22), Hilsenhoff Biotic Index (F_1,22= 0.12, p = 0.75), or EPT taxa richness (z= 3.66, df = 22, p = 0.74) between the avulsion and historic channels. We found that macroinvertebrate communities reached higher densities within the historic channel, but this difference was only near-significant (F_1,16= 3.67, p = 0.07). This study provided valuable baseline information on macroinvertebrate community composition throughout the proposed LBFS restoration site, broadly showing similarities in all community metrics evaluated. Future sampling should continue in subsequent years at sites throughout LBFS to evaluate effects of restoration on stream biota. Benthic macroinvertebrates show seasonal shifts in abundance and assemblage composition, and should therefore be sampled twice per year (late spring and late summer) to collect representative samples. Future sampling should also evaluate fine-scale differences in community composition between the historic and avulsion channels, paying particular attention to changes in sensitive taxa (e.g.; EPT families) in response to channel restoration efforts.
stream restoration, aquatic macroinvertebrates