Determination of stream reaches in a ridge and valley creek using diatom periphyton communities

We used the diatom periphyton communities that occurred in Penns Creek as m arkers for stream reach. Diatom scrapings were taken from rocks at six site s in Penns Creek and one site in Pine Creek, cleaned, prepared, and viewed with scanning electron microscopy. Counts were weighted for biovolumes in o rder to determine biomass percentage compositions of each species in the co mmunity. Similarity was calculated using the Bray-Curtis similarity index. Results show that diatoms can be used to determine stream reach, and doing so separate Penns Creek into three reaches during the summer, the time of h ighest reach stability.