PRIMARY RESEARCH PAPER Assessment of mine drainage remediated streams using diatom assemblages and biofilm enzyme activities Justin R. Pool • Natalie A. Kruse • Morgan L. Vis Received: 8 August 2012 / Revised: 19 December 2012 / Accepted: 29 December 2012 / Published online: 22 January 2013 Ó Springer Science+Business Media Dordrecht 2013 Abstract A legacy of pre-regulation coal mining in many areas has been acid mine drainage (metal-rich, low pH water). Today, numerous remediation strategies may be implemented, but there is little data on efficacy in restoring biological condition. Two alkaline doser projects in Ohio were assessed using diatom assem- blages, and biofilm extracellular enzyme activities (EEA). In one stream, water quality steadily increased downstream of the doser; pH increased from 3.8 to 7.2 and Fe decreased from 107 to 0.42 mg l -1 . Likewise, the periphyton biomass (chl a 7.15–12.77 mg m -2 ) increased and periphyton index scores (4–27) improved. As well, EEA data showed greater activity for phos- phorus, nitrogen, and one carbon acquisition enzyme. For the other stream, the conductivity remained high ( [ 720 lS cm -1 ) and pH and alkalinity decreased downstream. Biological data, including EEA, varied along the stream length with higher numbers in the middle reach, such as chlorophyll a (0.56 to 87.75 to 2.77 mg m -2 ), and index scores (7 to 29 to 11). The first remediation site showed positive results in chemistry, biological community and measures of ecosystem function. The second stream was highly variable in these parameters suggesting further AMD inputs are hampering recovery. Keywords Biomonitoring Á Acid mine drainage Á Water quality Á Diatom index of biotic integrity Á Mining Á Periphyton Introduction Mining for coal has been and is prevalent in many parts of the world. For the US, coal continues to be a primary energy source, with coal mining being a major industry since the Industrial Revolution. Coal is obtained through either surface or underground min- ing and, prior to the 1970s, few regulations existed regarding operation and subsequent reclamation of mine land (United States Government, 1977). The leftover mine spoils and abandoned mine pits from surface mining were saturated with water and even- tually drained into nearby waterways. Likewise, once an underground mine was abandoned, it typically filled with water and that water subsequently drained into the nearest stream. The legacy of pre-regulation mining has been acid mine drainage (AMD), which is characterized by low Electronic supplementary material The online version of this article (doi:10.1007/s10750-012-1440-2) contains supplementary material, which is available to authorized users. Handling editor: Nicholas R. Bond J. R. Pool Á M. L. Vis (&) Department of Environmental and Plant Biology, Ohio University, Porter Hall Rm. 315, Athens, OH 45701, USA e-mail: vis-chia@ohio.edu N. A. Kruse Voinovich School of Leadership and Public Affairs, Ohio University, Athens, OH 45701, USA 123 Hydrobiologia (2013) 709:101–116 DOI 10.1007/s10750-012-1440-2