HR: 1330h
AN: NB33G-10    [Abstracts]
TI: When the Well Runs Dry: Ecological Consequences of Dewatering Rivers
AU: * Miller, S W
EM: millersc@onid.orst.edu
AF: Department of Fisheries and Wildlife Oregon State University, Nash Hall Rm. #104, Corvallis, OR 97333 United States
AB: Disturbances related to river discharge are thought to define the physical template that structures biological communities and selects for effective life history strategies. Through managing river discharge to support agricultural production in arid and semi-arid landscapes, the timing, frequency, magnitude, and duration of low flow events has been altered. Despite the ubiquitous nature of this management practice, we are currently unable to predict when low flow events impose a disturbance on lotic ecosystems or the spatiotemporal extent of biotic responses. This poster outlines a study that examines gradients in water withdrawal intensity to: 1. Determine if macroinvertebrate communities and environmental variables exhibit threshold or proportional responses to channel dewatering; 2. Characterize spatiotemporal response and recovery patterns of macroinvertebrates to low flow disturbances; 3. Compare life history traits, growth, and developmental rates for invertebrates inhabiting different flow regimes. Preliminary results show macroinvertebrate community structure changing at greater spatial and temporal rates as compared to reference conditions when discharge is reduced by 75 percent or more. The characterization of macroinvertebrate response and recovery patterns to low flow events will help develop innovative strategies that allow agricultural water use, while mitigating structural and functional impacts on lotic systems.
DE: 1803 Anthropogenic effects
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly