HR: 09:00h
AN: NB21A-03 INVITED     [Abstracts]
TI: Intermittent Streams and Habitats Function as Refugia for Fish and Crayfish
AU: * Magoulick, D D
EM: danmag@uark.edu
AF: USGS, Arkansas Cooperative Fish & Wildlife Research Unit, Department of Biological Sciences University of Arkanasas, Fayetteville, AR 72701 United States
AU: Bare, C M
EM: cbare@uark.edu
AF: USGS, Arkansas Cooperative Fish & Wildlife Research Unit, Department of Biological Sciences University of Arkanasas, Fayetteville, AR 72701 United States
AU: Dekar, M P
EM: mdekar@uark.edu
AF: USGS, Arkansas Cooperative Fish & Wildlife Research Unit, Department of Biological Sciences University of Arkanasas, Fayetteville, AR 72701 United States
AU: Hodges, S W
EM: swhodge@uark.edu
AF: USGS, Arkansas Cooperative Fish & Wildlife Research Unit, Department of Biological Sciences University of Arkanasas, Fayetteville, AR 72701 United States
AU: Flinders, C A
EM: flinders@acnatsci.org
AF: Patrick Center for Environmental Research, Academy of Natural Sciences, Philadelphia, PA 19103 United States
AU: Dick, A
AF: University of Central Arkansas, Department of Biological Sciences University of Central Arkansas, Conway, AR 72035 United States
AB: Drought and summer drying can be important disturbance events in many small streams leading to intermittent or isolated habitats. We examined the influence of stream permanence on fish and crayfish population and community dynamics in multiple streams over several years. We found total crayfish densities and densities of some crayfish species were significantly greater in intermittent than in permanent streams, whereas crayfish species richness did not differ significantly between the two stream types. There was a significant relationship between crayfish relative abundance and abiotic environmental variables for permanent, but not intermittent streams. Fish densities were high in intermittent streams, especially for small species-size classes. Fish moved at large spatial and temporal scales to use intermittent streams, especially for spawning, and fish moved at smaller spatial and temporal scales to avoid drying habitats, especially riffles. During drying events fish survival was greater in pools than in riffles, and pools were more likely to remain permanent habitats. Intermittent streams and permanent pools within dry portions of stream appear to function as refugia for some species and size classes of fish and crayfish. Understanding this relationship will allow natural resource managers to implement effective conservation strategies for fish and crayfish in intermittent streams.
DE: 1800 HYDROLOGY
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly