Grant will expand use of ‘sensor fish’ in dams

Sep 14, 2011

RICHLAND, Wash. – As salmon wind their way through dams on the Columbia River, a small percentage ultimately end up passing through turbines. A project that helps fish move more safely through turbines recently received a grant to expand its scope.

Until about a decade ago, scientists didn’t know exactly what happened to fish during the seconds it takes them to pass through hydro turbines. That is until researchers at Pacific Northwest National Laboratory in Richland, Wash., invented the sensor fish.

This “robo fish” passes through turbines just as normal salmon do, but along the journey it collects data: How often fish hit blades, how rapidly they get decompressed – something scientists liken to the bends – and how turbulent the water is.

Enter the grant

Now through a Department of Energy grant, scientists are designing the fourth generation of sensor fish. Program manager Tom Carlson says unlike previous generations this mechanical fish is smaller and will more easily fit through turbines beyond the Columbia River.

“We’ll be able to look at some of the turbines that were put in place at locations that were not considered before.”

The synthetic salmon have allowed researchers to suggest structural changes and improvements to turbines old and new. One way to do this is to improve how water flows through turbines. Carlson says this helps fish, but it also generates power more efficiently.