HR: 10:30h
AN: NB22A-01 INVITED     [Abstracts]
TI: Structural and Functional Effects of Southern Redbelly Dace (Phoxinus erythrogaster)
AU: * Bertrand, K N
EM: bertrand@ksu.edu
AF: Kansas State University, Division of Biology, 232 Ackert Hall, Manhattan, KS 66056 United States
AU: Gido, K B
EM: kgido@ksu.edu
AF: Kansas State University, Division of Biology, 232 Ackert Hall, Manhattan, KS 66056 United States
AB: We used a combination of field and mesocosm experiments to measure the effects of southern redbelly dace (Phoxinus erythrogaster) on stream ecosystem structure and function. Ecosystem structure was quantified by algal filament length, algal biomass, size distribution of benthic organic matter, algal community composition, and invertebrate community composition. Ecosystem function was based on gross primary productivity (GPP). Throughout the experiments, dace changed ecosystem structure but not ecosystem function. The presence of Phoxinus resulted in reduced algal filament length and reduction in the mean size of benthic particulate organic matter (BPOM). Studies of other grazing minnows (e.g., central stoneroller Campostoma anomalum) also reported structural effects on stream ecosystems (i.e., reduced algal biomass, filament length, and mean BPOM size fraction) as well as effects on ecosystem function (i.e., net primary productivity). Although interspecific variation among grazing minnows may cause differences in ecosystem effects, the experimental context, including methodology, also can strongly affect the magnitude and nature of observed responses.
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly