The Little Tennessee River runs wide and deep just below Emory Dam, outside Franklin North Carolina. In the late-morning sun on an April day, a jon boat plied the water back and forth. Protruding from the bow and dropping into the water was a pair of electrodes wired to an on-board generator. Perched in the bow was a biologist with a long-handled net waiting to scoop up fish stunned by the electric current flowing through the water.