This study examines the behavioural responses of juvenile chinook salmon in riverine and vertically stratified estuarine conditions and to hypoxia within a water column simulator. Swimming speeds, schooling behaviour and distribution were quantified in relation to the simulated conditions through the analyis of time-lapse video tape recording. Temporal changes were examined by conducting a series of experiments encompassing the period of natural downstream migration, estuarine residence, and entry into sea water. This report presents data generated from these analyses together with graphical examples of the responses of underyearling salmon to the imposed conditions.