For generations, the death toll of young salmon passing through hydroelectric dams was attributed to the obvious violence of spinning steel — yet the bodies told a quieter, more invisible story. Researchers in the Pacific Northwest discovered that it is not the blade but the void behind it, a catastrophic collapse of pressure lasting mere seconds, that ruptures swim bladders and kills millions of smolts each spring. By sending instrumented robots through working turbines and recreating the experience in laboratory chambers, scientists transformed an unseen physical force into a measurable, and
Pressure, Not Blades, Kills Salmon in Dam Turbines, Study Reveals
Millions of young salmon die annually passing through Columbia and Snake river dams; research-driven turbine redesigns aim to reduce this mortality.