HR: 16:45h
AN: NB24A-06    [Abstracts]
TI: Evaluation of the Representative Reach Sampling Methodology for Biomonitoring Using Benthic Macroinvertebrates
AU: * Orr, J C
EM: jorr@srbc.net
AF: Susquehanna River Basin Commission, 1721 N. Front Street, Harrisburg, PA 17102 United States
AU: * Orr, J C
EM: jorr@srbc.net
AF: The Pennsylvania State University, School of Forest Resources, 113 Ferguson Building, University Park, PA 16802 United States
AU: Ferreri, C P
EM: cpf3@psu.edu
AF: The Pennsylvania State University, School of Forest Resources, 113 Ferguson Building, University Park, PA 16802 United States
AU: Nieman, D
EM: dnieman@normandeau.com
AF: Normandeau Associates, 400 Old Reading Pike, Building A, Suite 101, Stowe, PA 19464 United States
AU: Martin, T H
EM: tmartin@wcu.edu
AF: Western Carolina University, Department of Biology, 132 Natural Science Building , Cullowhee, NC 28723 United States
AB: Bioassessments by resource management agencies to determine the condition of streams often rely on sampling benthic macroinvertebrate assemblages in "representative reaches". That information is used to represent assemblages in other reaches with similar characteristics. The goal of our study was to evaluate the effectiveness of using "representative reach" sampling to characterize assemblages at different scales (local-regional). During summer 1999, we sampled assemblages in a relatively undisturbed area in northwestern Pennsylvania using a nested design (n=81) to describe variation in assemblages at different scales. We found that assemblages changed gradually along the stream continuum rather than forming discrete groups based a priori on knowledge of environmental variables. Taxa richness in any sample averaged 12.5% of total taxa richness summed across all scales, requiring 4-30 1-m² samples to be taken in any reach to capture the majority (>70%) of taxa. Due to the continuous nature of assemblages, and the inability to collect the majority of taxa in any sample, caution should be used in relying solely on representative sampling to characterize other assemblages. An iterative process of refinement using a posteriori knowledge to test validity of methods should be used in establishing biomonitoring programs to assure accuracy and precision in management decisions.
DE: 0400 Biogeosciences
DE: 1824 Geomorphology (1625)
DE: 9800 GENERAL OR MISCELLANEOUS
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly