HR: 1330h
AN: NB33O-06    [Abstracts]
TI: Effects of Urbanization and Colonization of Hydrilla verticillata on the Macroinvertebrate Community Structure in Tributaries to the Lower St. Johns River, Florida
AU: * Thiele, J E
EM: thiel002@bama.ua.edu
AF: Aquatic Biology Program, Department of Biological Sciences University of Alabama, Tuscaloosa, AL 35487
AU: Chadwick, M A
EM: chadwick@bama.ua.edu
AF: Aquatic Biology Program, Department of Biological Sciences University of Alabama, Tuscaloosa, AL 35487
AU: Dobberfuhl, D R
EM: ddobberfuhl@sjrwmd.com
AF: Division of Environmental Sciences Saint Johns River Water Management District, 4049 Reid St., Palatka, FL 32177
AU: Benke, A C
EM: abenke@bama.ua.edu
AF: Aquatic Biology Program, Department of Biological Sciences University of Alabama, Tuscaloosa, AL 35487
AU: Huryn, A D
EM: huryn@bama.ua.edu
AF: Aquatic Biology Program, Department of Biological Sciences University of Alabama, Tuscaloosa, AL 35487
AU: Suberkropp, K
EM: ksuberkp@biology.as.ua.edu
AF: Aquatic Biology Program, Department of Biological Sciences University of Alabama, Tuscaloosa, AL 35487
AB: We are investigating relationships between urbanization and macroinvertebrate communities in 20 tributaries of the St. John's River, Florida. Preliminary data are available for three streams. The first is unimpacted (=reference), the second is urbanized but has a forested riparian zone (=urban), while the third is urbanized but lacks a forested riparian zone (=Hydrilla). Due to the lack of shading this third stream has been colonized by the invasive macrophyte Hydrilla verticillata. Macroinvertebrate taxa richness was 25 for the reference, 15 for the urban, and 45 for the Hydrilla stream. Densities for the reference, urban, and Hydrilla streams were 2,546, 7,026, and 24,451 ind/m², respectively. The increase in diversity and density in the Hydrilla stream may be a result of a shift from a lotic to a more lentic environment. Functional feeding-group composition varied between streams. The reference had the greatest proportion of filter-feeders (26% vs 5-6% of ind/m²). The Hydrilla stream had the greatest proportion of predators (9% vs 2-4%) and scrapers (12% vs 1%). The urban stream had the greatest proportion of collector-gatherers (90% vs 66-71%). These preliminary data indicate that quantitative and qualitative differences in land-use/land-cover can have substantial influences on community functional attributes of small subtropical streams.
DE: 1803 Anthropogenic effects
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly