Video

Video by Chief Petty Officer Matthew Cole

Passive Integrated Transponder

U.S. Army Corps of Engineers Walla Walla District

Nov. 25, 2019 | 1:07

The U.S. Army Corps of Engineers Walla Walla District, in conjunction with NOAA and the Pacific States Marine Fisheries Commission, began installing the Passive Integrated Transponder (PIT) tag monitoring antenna system in the Lower Granite Dam spillway on Nov. 21.
The monitoring system will be the first of its kind to read and store PIT tag data collected in the high-velocity spillway environment on the Snake/Columbia river system.

Prior to this project, PIT tag data for outmigrating juvenile salmon and steelhead could only be collected when the fish pass through the Juvenile Bypass System to be either returned to the river or transported downstream in a fish barge. In recent years, more and more emphasis has been placed on keeping the fish in the river and passing the dams via the spillway rather than the bypass system. When the spillway PIT tag monitoring system is operational, it will provide a much larger data set for regional fish managers to use to evaluate system performance and make decisions about future system operations.