Sensitive Streams: Seasonal Assessments of Benthic Macroinvertebrate Community Assemblage at Five Headwater Streams in Central Pennsylvania

This was the end of the second year of a survey of five headwater streams in Bald Eagle State Forest (Little Weikert, Green Gap, Lick, Coral and Henstep Run), each of which forms a separate cut on Penns Creek Mountain. Conductivity (11-29 µs/cm) and buffering capacity (57.37-304 µeq/L) are low, pH varied between 4.85 and 6.84, but the average pH remained below 6.5 across all sites. We sampled each stream for benthic macroinvertebrates (BMI) using the PADEP six kick method within a one-hundred-meter reach each season which were later identified to family-level taxonomy. Compared to samples taken during the summer of 2015, we saw a higher Proportional Bray-Curtis similarity in communities between streams during 2016 (24%-55% and 36%-80%, respectively). Bray-Curtis similarity in communities between streams sampled during the fall of 2016 were slightly lower than those observed during the fall of 2015 (31%-74% and 37%-62%, respectively).