Physiological Response of Rainbow Trout to Sediment Released during Open-Cut Pipeline Water Crossing Construction

The physiological response of rainbow trout exposed to elevated suspended sediment concentrations downstream of two open-cut pipeline water crossings was investigated. Trout held in cages downstream of construction had increased respiration rates and shorter times till loss of equilibrium during sealed jar bioassays. Differences in blood hematocrit levels between experiments and transects is attributed to sediment concentration and particle size. Sediment exposure did not result in gill damage or fish mortality. The observed level of physiological effect was consistent with the predictions of the sediment-effects dose-response equation for salmonids.