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TEMPORAL VARIATION IN OHIO RIVER MACROINVERTEBRATES: A HISTORICAL ROCK BASKET COMPARISON, 1960'S TO PRESENT
Citation:
Wooten, M. S., E. B. Emery, AND B R. Johnson. TEMPORAL VARIATION IN OHIO RIVER MACROINVERTEBRATES: A HISTORICAL ROCK BASKET COMPARISON, 1960'S TO PRESENT. Presented at North American Benthological Society, Vancouver, Canada, June 6-10, 2004.
Impact/Purpose:
The purpose of this research project is to provide methods, tools and guidance to Regions, States and Tribes to support the TMDL program. This research will investigate new measurement methods and models to link stressors to biological responses and will use existing data and knowledge to develop strategies to determine the causes of biological impairment in rivers and streams. Research will be performed across multiple spatial scales, site, subwatershed, watershed, basin, ecoregion and regional/state.
Description:
Collection of representative macroinvertebrate samples has historically been a problem for researchers working on the Ohio River. The USEPA utilized rock basket artificial substrates to sample benthic assemblages from 1964-1971. By this method, a steel basket (7" diameter, 11" long) was filled with 2 - 3 inch limestone aggregate and suspended by steel cable in 2 - 3 feet of water. The baskets were generally suspended from lock chamber walls, although other permanent structures, such as concrete water intakes, were also used. The objective of this study was to repeat these rock basket surveys in order to accurately observe temporal trends within the macroinvertebrate community. Rock baskets were deployed in late summer 2002 in the same general areas of the historical studies and were allowed to colonize for the same six week time period. Macroinvertebrates collected from baskets were examined using a community similarity index, nonmetric multidimensional scaling, and a draft macroinvertebrate index developed for the Ohio River. Results indicated the 2002 data were distinct from historic data and showed increases in taxa richness, sensitive species, and index scores. Our findings indicate marked improvement in the macroinvertebrate community since passage of the 1972 Clean Water Act.