586 Sediment and epilithon metabolism and hydrolytic activity in streams affected by mountaintop removal coal mining, West Virginia, USA

Thursday, May 21, 2009: 2:00 PM
Ambassador West
Ken M. Fritz , U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Division, Cincinnati, OH
Brent Johnson , Office of Research and Development, National Exposure Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH
Rachel Price , Federal Energy Regulatory Commission, Washington, DC
Mountaintop removal and valley filling (MTR/VF) is a method of coal mining used in the Central Appalachians.  Despite regulations requiring that potential impacts to stream function be considered in determining compensatory mitigation associated with permitted fill activities, assessments of MTR/VF have only included structural measures.  We measured sediment and epilithon metabolism and hydrolytic activity (fluorescein diacetate) seasonally in 10 streams (5 forested and 5 mined) to determine the feasibility of these functional measurements.  Sediment metabolism and hydrolytic activity were significantly higher in forested streams than in mined streams across all seasons.  Epilithic metabolism was significantly higher in forested streams than in mined streams in October, but did not vary in February, April or July.  Metabolism and hydrolytic activity were strongly correlated.  The percent cover by fine sediment was negatively correlated with epilithic metabolism and hydrolytic activity, whereas the total upstream channel length was positively correlated with sediment metabolism and hydrolytic activity.  All measures were negatively related to specific conductance.  These results suggest that MTR/VF has negative effects on stream function by truncating stream networks, altering water chemistry, and increasing sedimentation.  Combining functional measures with traditionally used structural measures will provide a more complete assessment of ecosystem integrity.