Sensor 'Fish' Measures Journey Through Hydroelectric Dams

by / November 11, 2014

For young salmon in the Pacific Northwest, the trek toward the ocean is a treacherous one -- it must dodge predatory birds and sea lions, and hydroelectric dams introduce manmade currents that sweep fish past swirling turbines and other obstacles.

Though most juvenile salmon survive this journey every year, scientists at the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL) are using an upgraded synthetic fish to help existing hydroelectric dams and new, smaller hydro facilities become more fish-friendly. The latest version of this Sensor Fish, pictured below, is a small tubular device filled with sensors that analyze the physical stresses fish experience. And, compared to its predecessor, it measures more forces, costs about 80 percent less and can be used in more hydro structures, according to the PNNL.


"The earlier Sensor Fish design helped us understand how intense pressure changes can harm fish as they pass through dam turbines," said lead Sensor Fish developer Daniel Deng, a chief scientist at the Department of Energy's PNNL, in a press release. "And the newly improved Sensor Fish will allow us to more accurately measure the forces that fish feel as they pass by turbines and other structures in both conventional dams and other hydro power facilities. As we're increasingly turning to renewable energy, these measurements can help further reduce the environmental impact of hydropower."

The upgraded sensor fish is the same size as a juvenile salmon -- approximately 3.5 inches long and 1 inch in diameter -- and measures pressure, acceleration, strain and turbulence, among other things. It weighs about 1.5 ounces and costs $1,200.