Journals Proceedings

Abstract

Although tidal energy is promoted as sustainable and clean, about 20 – 80 % of fish passing through a tidal barrage are killed. The moving turbine blades create sights and sounds, which act as warnings to fish. Fish which have not heeded the warning, are eliminated from the Darwinian struggle for survival. In comparison, dogs learn to maneuver through cars on busy city streets. This paper proposes to enhance the warning signals to marine life encouraging (scaring) them to stay away. The warnings can be both visual and auditory. Visual stimuli can be brightly colored patterned turbine blades, accompanied by flashing lights. Auditory warning signals can be clicks that fish are sensitive to. The intensity of lights and sounds should be that they are out of range to fish at a safe distance away. The precise nature of the audio-visual warnings will depend on the, visibility, turbine speed, water speed, fish sensitivity etc. The problem is not unlike using added audio-visual warnings to keep birds and bats away from wind turbines. Simple warnings are likely to greatly reduce the mortality rates of fish from the blades, and promote continued growth of of tidal energy.