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DEVELOPMENT OF BENTHIC MACROINVERTEBRATE INDEX FOR MEASURING THE CONDITION OF STREAMS AT A REGIONAL SCALE
Citation:
Cormier, S M., D J. Klemm, AND F A. Fulk. DEVELOPMENT OF BENTHIC MACROINVERTEBRATE INDEX FOR MEASURING THE CONDITION OF STREAMS AT A REGIONAL SCALE. Presented at National Science Meeting, Toronto, Canada, January 18-20, 2000.
Impact/Purpose:
The goal of this research is to develop methods and indicators that are useful for evaluating the condition of aquatic communities, for assessing the restoration of aquatic communities in response to mitigation and best management practices, and for determining the exposure of aquatic communities to different classes of stressors (i.e., pesticides, sedimentation, habitat alteration).
Description:
A multimetric macroinvertebrate index of stream condition was developed for the Mid-Atlantic Highlands Region of the United States. Benthic macroinvertebrate samples were collected from 562 first through third order streams between 1993 and 1995. Macroinvertebrates were collected from riffles or runs and identified to the lowest possible taxon (genus and species). Measurements of physical habitat and water chemistry were collected at 407 stream sites. Forty-two candidate metrics were evaluated in a logical, statistical process that eliminated metrics using three criteria: 1) each metric's ability to discriminate sites with better chemical and physical habitat indicators from impaired sites; 2) each metric's independence or lack of redundancy with other metrics; and 3) each metric's relationship with stressors. Final selection of eight metrics was based on best performance for redundant (autocorrelated) metrics, ecological relevance, acceptance by scientific community, and added value to the performance of the complete index. The final Stream Benthos Invertebrate Index (SBII) consisted of eight metrics: total number of taxa, number of EPT taxa, % intolerant taxa, % non-insect individuals, % chironomid taxa, % plecoptera taxa, % oligochaete/leech individuals, and the Hilsenhoff Biotic Index (HBI). When the index was compared with the first axis from a principal component analysis using the original forty-two metrics, the correlation was highly significant. The process that was used to develop the index provides confidence because it is based on a jargon, logical process that is consistent with ecological theory using metrics that are accepted by state biologists. Furthermore, there is independent evidence of ability to detect impairment and independent confirmation from multivariate analysis. Thus, comparisons of biological conditions in streams can be confidently reported across regional scales.