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 30.5cm-diameter thin-walled pipe into which compressed air was delivered. Fish were lifted from water depths of 14-25 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.

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A large box net was constructed to capture migrating juvenile salmonids from turbine intake gatewells at hydroelectric dams. This net, operated at John Day Dam on the Columbia River, caught an average of 97.3% of the fall chinook salmon Oncorhynchus tshawytscha smolts present in the gatewells. The net is presently being used at other hydroelectric dams on the Columbia River system.

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