HR: 10:30h
AN: NB42D-01 INVITED     [Abstracts]
TI: Correlation of Invertebrate Drift Density and Colonization Density on Submerged Wood During Rising and Falling Water Levels: Efficiency of Colonization
AU: * Weibell, B J
EM: benjamin.j.weibell@ua.edu
AF: Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487 United States
AU: Benke, A C
EM: abenke@biology.as.ua.edu
AF: Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487 United States
AB: Submerged wood is the major solid substrate available for invertebrate colonization in Coastal Plain rivers, and the quantity of wood submerged varies with discharge. As water level drops, invertebrates enter the drift, potentially to colonize other submerged wood. When water level rises, drifting animals colonize newly inundated habitat. We measured wood colonization and invertebrate drift monthly from February through July in the Sipsey River, Alabama. Samples were taken during rising and falling water levels to test how changes in water level affected rates of drift and colonization, and to determine whether there was a correlation between drift rates and colonization rates. The drift consisted of invertebrates originating from wood and floodplain habitats. No consistent differences in either drift or colonization were correlated with changing water levels. However, there was a strong correlation (0.93) between drift and colonization of wood-dwelling invertebrates. The highest 7-day colonization density was 44,249 animals/m² of wood surface with a biomass of 1868 mg/m². Minimum density and biomass were 4325 animals/m² and 258 mg/m². Drift of potential colonizers ranged from 4.90 to 1.98 animals/m²/s. Colonization densities calculated from drift rates agreed closely with actual 7-day colonization densities. This indicated that drifting invertebrates efficiently colonized any wood encountered.
DE: 1812 Drought
DE: 1821 Floods
DE: 1845 Limnology
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly