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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Ecotoxicology
BIOASSESSMENT OF A WATERSHED INFLUENCED BY POSTMINING COAL ACTIVITIES.
T.C. Merricks, D.S. Cherry, R.J. Currie, and C.E. Zipper. Department of Biology, Virginia Polytechnic and State Institute, Blacksburg, Virginia
The Middle Creek watershed in Tazewell County, VA, is subject to multiple postmining coal influences, such as drainages from three hollow fills and an abandoned coal processing plant (ACPP). In the summer of 2001, laboratory 48 hr acute water column bioassays with Ceriodaphnia dubia indicated severe toxicity levels from three of five ACPP settling ponds which drain into Middle Creek, with LC50 values ranging from 1.4–20.6%. However, the three major hollow fill drainages in Middle Creek only had a subtle toxic effect upon C. dubia. Benthic macroinvertebrate samples were collected in Middle Creek from nine survey stations and an unimpacted reference area to better assess the impact upon the biotic communities. Taxa richness was significantly lower than the reference station at a site adjacent to the ACPP, whereas EPT richness was significantly lower than the reference at four stations associated with hollow fill drainages and the ACPP drainages. Additionally, Ephemeroptera populations were most significantly reduced at the oldest hollow fill (13 yr) that discharges the most leachate. Upon data analysis, hollow fill age was not correlated to severity of negative influence upon biotic communities.
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