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STANDARDIZED ASSESSMENT METHOD (SAM) FOR RIVERINE MACROINVERTEBRATES
Citation:
Flotemersch, J E., K A. Blocksom, J J. Hutchens, B C. Autrey, AND D J. Klemm. STANDARDIZED ASSESSMENT METHOD (SAM) FOR RIVERINE MACROINVERTEBRATES. Presented at Biological Advisory Committee Meeting, Washington, DC, October 7-10, 2002.
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:
During the summer of 2001, twelve sites were sampled for macroinvertebrates, six each on the Great Miami and Kentucky Rivers. Sites were chosen in each river from those sampled in the 1999 methods comparison study to reflect a disturbance gradient. At each site, a total distance equal to 40 times the mean wetted width was sampled at specific intervals. Timed kick net and dip/pick samples were combined into a single sample for each transect and bank. All samples were sorted up to a maximum of 2000 organisms. Using Monte Carlo simulation, samples from successively longer distances across both banks were combined, and 100-, 200-, and 300-organism sub-samples were randomly selected. This process was repeated 100 times per sub-sample size, and the mean metric value for each site was plotted against distance sampled. Total taxa richness and Ephemeroptera richness increased and separation of sites improved with increasing sub-sample size. Percent Ephemeroptera curves were unaffected by sub-sample size. Metric values usually reached an asymptote within a distance of 500 m. Future testing of this method over a 500-m reach in other rivers and evaluating relationships with habitat and chemistry is planned.