|Document Type:||Journal Article|
|Title:||An air-lift pump for sampling juvenile salmonids at John Day Dam|
|Author:||Dean A. Brege, Winston E. Farr, Richard C. Johnsen|
|Journal:||North American Journal of Fisheries Management|
An air-lift pump system was designed and constructed to sample juvenile salmonid accumulations in the turbine-intake gatewells of John Day Dam on the Columbia River. A funnel concentrated fish into a 30.5-cm-diameter thin-walled pipe into which compressed air was delivered. Fish were lifted from water depths of l 4-25 m to heights of 1-7.3 m above the water surface. With a 14-m submergence and 1-m head, the sampling system operated continuously, dependably, and economically, providing hourly estimates of salmonid passage with little or no injury to fish.