Diel and seasonal movements of White Sturgeon (Acipenser transmontanus) in the mid-Columbia River.

Abstract

In the mid-Columbia River, radio-tagged White Sturgeon (Acipenser transmontanus) exhibited seasonal and diel movement patterns from 1975-1977. Seasonally, movements >2 km away from release locations began in spring when water temperature exceeded 13 oC and ended in autumn when water temperature fell below 13 oC. Daily, sturgeon exhibited movements among habitats with different substrates, as measured by changes in water temperature during 24-h diel periods. Movement to cooler, deeper areas of the river occurred before sunrise, while movement to warmer, shallower areas peaked after sunset. Because water temperatures varied by only a few tenths of a degree among substrate areas, it is likely that photoperiod influenced sturgeon movements between deeper, darker resting areas and shallower, food-rich feeding areas.