Temporal Dynamics of Benthic Macroinvertebrate Communities and Their Response to Elevated TDS in Appalachian Coalfield Streams

Abstract

Maintaining integrity of benthic macroinvertebrate communities in Appalachian coalfield headwater streams is a key concern. Total dissolved solids (TDS) are ubiquitous as dissolved constituents in surface waters and often occur at elevated levels in streams draining Appalachian coal mines. Most TDS in surface waters originate from the dissolution of rock and mineral materials that are exposed to the natural elements; this process is accelerated in mining regions, as surface mines cause large volumes of fresh, unweathered rock material to be fractured, brought to the surface, and exposed to accelerated weathering processes. The concentration of TDS is closely related to specific conductance (SC), which is the ability for water to conduct a current at 25º C. We have been conducting research to identify benthic macroinvertebrate community composition relationships with TDS in southwestern Virginia’s mining area, where geology and environmental conditions are similar to adjacent coal‐mining areas of eastern Kentucky and southern West Virginia. This report summarizes the first year of a two‐year study, aimed to expand understanding of temporal variability within the benthic macroinvertebrate community in elevated‐TDS streams. Eleven sets of benthic macroinvertebrate and water quality grab samples have been collected to date and are being analyzed; and continuous conductivity loggers have been installed in all streams. Sampling will conclude in November 2012.