Embodiments of the present invention provide a novel deterrent barrier based on the phenomenon of fluid cavitation. A drive unit comprising a motor and a propeller are configured for inducing cavitation in water. The cavitation takes the form of a rotationally confined vertical column of cavitation bubbles extending from the propeller, and a one-dimensional series of drive units spanning the width of a waterway may provide an effective, environmentally friendly and non-lethal barrier against entry of target fish species.
