HR: 16:00h
AN: NB24B-03    [Abstracts]
TI: A 28-Year Comparison of Urbanization Effects on Stream Macroinvertebrate Richness and Secondary Production
AU: * Pollock, J B
EM: pollo001@bama.ua.edu
AF: University of Alabama, Aquatic Biology Program Box870206 , Tuscaloosa, AL 35487 United States
AU: Benke, A C
EM: abenke@biology.as.ua.edu
AF: University of Alabama, Aquatic Biology Program Box870206 , Tuscaloosa, AL 35487 United States
AB: Long term changes in urbanization and stream invertebrate communities were investigated from analysis of data collected 28 years apart in the Atlanta, Georgia metropolitan region. Twenty-one streams were selected for study in 1975, and the same streams were studied in 2003 (minus two streams flooded by reservoir construction). Watersheds ranged in land use from 0 to 97% urban across years, but the degree of urbanization increased substantially for many of the previously more natural sites after 28 years. Four modified Hester-Dendy samplers were placed in each stream in July of each year of study for a period of 4-5 weeks. Upon collection, all macroinvertebrates were identified to the lowest possible taxonomic resolution (species or genus) and lengths were measured. Macroinvertebrate richness and an index of secondary production were determined for each sampler in all streams. Biomass was estimated using taxon-specific length-mass regressions, and production was estimated using empirical models of production/biomass values. Richness ranged from <7 to 32 taxa per sampler and production ranged from 0.1 to 4.9 mg dry mass sampler^-1 day^-1. Both taxa richness and production had a significant relationship with percent urban land-use (p<0.01). The relationship of invertebrate richness and production with increasing urbanization will be discussed.
DE: 1803 Anthropogenic effects
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly