BOAT lovers beware: the noise from your engines may be stressing out fish. Lidia Wysocki and her colleagues at the University of Vienna, Austria, recorded underwater ship noise from the river Danube and two Austrian lakes and played it back in the lab at similar volumes, 153 decibels, to common carp, European perch and gudgeon. After 30 minutes they measured the amount of cortisol, a common marker of stress, released into the water through the fishes’ gills.
They repeated the experiment using no noise and hissing white noise at 156 decibels – about as loud as a pistol shot. Fish…
