Lavigne, H. R. Oregon State University, hank@mail.cor.epa.gov
Greene, M. R. Dynamac Corp., greenem@mail.cor.epa.gov
Landers, D. H. U.S.EPA, NEERHL, Western Ecology Division, landers@mail.cor.epa.gov

 
DIEL MOVEMENT OF ADULT LARGESCALE SUCKER IN THE ALLUVIAL UPPER WILLAMETTE RIVER, OREGON, DURING REGULATED SUMMER LOW-FLOW
 
The diel movement of adult largescale sucker (Catostomus macrocheilus) was observed, using radio telemetry, a GPS, and night-vision gear, on the alluvial upper Willamette River, Oregon, during the summer low-flow of 1998. The objective was to to determine the extent of nocturnal inshore movement, and the frequency of use of off-channel floodplain features. Adult largescale sucker showed significant inshore movement at night. Most movement occured within the mainstem, with movement from relatively deep areas, used diurnally, to gravel-cobble shallows at night. A modest percentage of tagged sucker migrated into parapotamon, or seasonally lentic side-arms, at night. We present a preliminary analysis of this movement and discuss the alternate hypotheses that explain this behavior.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS47TU0492S