Comparison of benthic diatom assemblages from streams draining abandoned and reclaimed coal mines and nonimpacted sites

Abstract

We examined whether there was a particular group of diatoms specific to acid mine drainage (AMD) sites and/or reclaimed sites in streams in a coal-mining region of southeastern Ohio. Streams were initially placed into 5 categories: 1) stream receiving AMD from an unreclaimed site, 2) stream receiving drainage from a site reclaimed prior to a 1972 regulation, 3) stream receiving drainage from a site reclaimed between 1972 and 1982 under Ohio Revised Code (ORC) 1513, 4) stream receiving drainage from site reclaimed after 1982 under the Surface Mining Control and Reclamation Act (SMCRA), and 5) stream not impacted by AMD. The diatom flora from riffles in each system and environmental parameters (pH, conductance, metal concentrations [Al, Fe, Mn], current velocity, width, and depth) were examined to assess the recovery of reclamation sites from mining. Canonical correspondence analyses separated heavily impacted AMD streams from other sites. Total alkalinity and pH were highly correlated to the 1st axis, and SO4, average depth, and temperature were influential in additional axes. Discriminant analyses of the diatom and environmental data sets were successful in assigning samples into 1 of the a priori stream categories (85% and 81.8% accuracy, respectively). AMD streams were characterized by a dominant flora of Eunotia exigua and Frustulia rhomboides. Streams that fluctuated between acidic and circumneutral pH (termed oscillating) had greater abundances of Brachysira vitrea than other study streams. Streams of intermediate water quality (i.e., reclaimed sites) were dominated by Achnanthidium minutissimum. There was a predictable relationship between post-reclamation stream water quality and diatom assemblages, which may prove useful in assessment and management of reclamation efforts.