HR: 1330h
AN: NB33B-08    [Abstracts]
TI: Two-Year Comparison of a Stream Macroinvertebrate Functional Group Bioassessment Protocol for the Republic of Palau Archipelago
AU: * Olesen, A A
EM: olesenaa@notes.udayton.edu
AF: University of Dayton, Department of Biology, Dayton, OH 45469-2320 United States
AU: Benbow, M E
EM: benbow@msu.edu
AF: Michigan State University, Department of Entomology, East Lansing, MI 48824 United States
AU: Holm, T
AF: Forestry Unit-Bureau of Agriculture Ministry of Resources and Development, Palau Forestry Service, Koror, Palau
AU: Burky, A J
EM: albert.burky@notes.udayton.edu
AF: University of Dayton, Department of Biology, Dayton, OH 45469-2320 United States
AB: Macroinvertebrate functional feeding group data was collected in 2003 and 2004 to develop a rapid bioassessment protocol for Palauan streams. One reference stream, Ngardmau, was selected to test functional group ratios and associated ecosystem attributes against streams of variable impact. In both years qualitative samples were collected using 30s dip net samples in pool habitats and benthic scouring methods in cascades with additional quantitative cascade collections for sampling technique comparisons in 2004. In the reference stream riffle habitat, filtering-gatherers dominated the community (89.92% in 2003 and 47.37% in 2004) compared to all other functional groups. Among the impacted streams, riffle functional group composition was variable compared to the reference stream. In reference pool habitats, gathering-collectors and scrapers dominated in 2003 and 2004, respectively. Scrapers dominated pool habitats of impacted streams in 2004, with some functional groups missing. Changes in ecosystem attributes followed functional group variability depending on degree of impact. Functional group ratios indicated channel stability ratio ([filtering-collectors + scrapers]/[shredders + gathering-collectors]) was lowered with increasing impact, suggesting food and/or habitat quality for filtering-collectors was degraded in riffle habitats in 2003 with no trends in 2004. By this protocol streams were determined to be degraded in 2004 relative to 2003.
DE: 0400 Biogeosciences
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly