HR: 1330h
AN: NB33B-06    [Abstracts]
TI: Sensitivity and Reproducibility of a Family-level Macroinvertebrate Index used to Assess Acid Mine Impacts on Streams in the Western Allegheny Plateau
AU: * Johnson, K S
EM: johnsok3@ohio.edu
AF: Department of Biological Sciences, Ohio University, Athens, OH 45701
AB: We report on the performance of a family-level multimetric index, the MAIS (Macroinvertebrate Aggregate Index for Streams) for assessing acid mine impaired (AMD) sites in the Western Allegheny Plateau (Ohio). Two sampling protocols were compared, one utilizing three collection techniques (kick net, dip net and Surber samples), the other using two (kick and dip net). Including Surber samples tended to increase the MAIS score, changing the classification of four out of 52 sampling events (7.7%), but substantially increased processing time. MAIS scores were positively correlated with water pH (R = -0.77) and other indicators of AMD (acidity, sulfates, conductivity, total Al, total Mn). MAIS scores at some sites were consistent over 2-3 years of repeated sampling, others were more variable. Nineteen of the 26 sites that were sampled multiple times were categorized the same each year (73%), whereas 7 were classified differently in at least one year (27%). Since rainfall, flow regime and disturbance events varied over the three years, we cannot identify whether this variation reflects sampling error or actual changes in the assemblages at each site. Nevertheless, a benefit of repeated, annual evaluation is a statistically strong baseline condition against which future changes can be assessed.
DE: 1803 Anthropogenic effects
DE: 1845 Limnology
DE: 1871 Surface water quality
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly