Making dams safer for fish around the world

Tom Rickey at the Pacific Northwest National Laboratory: Think of the pressure change you feel when an elevator zips you up multiple floors in a tall building. Imagine how you'd feel if that elevator carried you all the way up to the top of Mt. Everest — in the blink of an eye. That's similar to what many fish experience when they travel through the turbulent waters near a dam. For some, the change in pressure is simply too big, too fast, and they die or are seriously injured.

In an article in the March issue of the journal Fisheries, ecologists from the Department of Energy's Pacific Northwest National Laboratory and colleagues from around the world explore ways to protect fish from the phenomenon, known as barotrauma.

Among the findings: Modifying turbines to minimize dramatic shifts in pressure offers an important way to keep fish safe when passing through dams. The research is part of a promising body of work that aims to reduce such injuries by improving turbine designs in dams around the world.

PNNL researchers are working with officials and scientists from Laos, Brazil, and Australia — areas where hydropower is booming — to apply lessons learned from experience in the Pacific Northwest, where salmon is king and water provides about two-thirds of the region's power. There, billions of dollars have been spent since 1950 to save salmon endangered largely by the environmental impact of hydropower.

"Hydropower is a tremendous resource, often available in areas far from other sources of power, and critical to the future of many people around the globe," said Richard Brown, a senior research scientist at PNNL and the lead author of the Fisheries paper. "We want to help minimize the risk to fish while making it possible to bring power to schools, hospitals, and areas that desperately need it," added Brown....

A sluice at Brazil's Itaipu Dam, shot by Herr stahlhoefer, public domain