HR: 16:15h
AN: NB24D-04    [Abstracts]
TI: The independent and interactive effects of reduced streamflow and fine sediment deposition on macroinvertebrate community structure and function.
AU: * Albano, C M
EM: calbano@lamar.colostate.edu
AF: Colorado State University, Department of Biology, Fort Collins, CO 80523 United States
AU: Hurst, B E
EM: behurst@engr.colostate.edu
AF: Colorado State University, Department of Civil Engineering, Fort Collins, CO 80523 United States
AU: Poff, N L
EM: poff@lamar.colostate.edu
AF: Colorado State University, Department of Biology, Fort Collins, CO 80523 United States
AU: Bledsoe, B P
EM: bbledsoe@engr.colostate.edu
AF: Colorado State University, Department of Civil Engineering, Fort Collins, CO 80523 United States
AB: Fine sediment deposition is a major cause of benthic habitat degradation and macroinvertebrate community impairment in stream ecosystems. Reduction in streamflow caused by human extraction of water can have dramatic effects on sediment transport dynamics, often resulting in an increase in fine sediment deposition downstream of the diversion structure. While reduced streamflow and fine sediment deposition are both known to affect benthic communities, the independent and interactive effects of these habitat alterations have not been addressed. This research is aimed at decoupling these effects. In autumn, 2004, colonization boxes containing 5 different levels (percent, by mass) of fine sediments were implanted in a gravel-bed mountain stream and exposed to 4 different levels of streamflow (15, 33, 67, 100 percent of ambient). Aquatic macroinvertebrate colonization was measured after 4 and 8 weeks. We predicted that community structure and diversity would become impaired as fine sediments increased and streamflow decreased. Moreover, we hypothesized that particular species traits such as rheophily, habit, feeding type, and respiration mode would show sensitive and differential responses to flow and fine sediment treatments. Results from this research are expected to provide insight into the mechanistic causes of benthic community impairment associated with water diversions in mountain streams.
DE: 1803 Anthropogenic effects
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly