Potential Implications of Acoustic Stimuli As a Non-Physical Barrier to Silver (Hypophthalmichthys molitrix) and Bighead Carp (H. noblis)

The effectiveness of an acoustic barrier to deter the movement of silver (Hypophthalmichthys molitrix) and bighead (H. noblis) carp was evaluated. A pond (10 x 5 x 1.2 m) was divided in half by a concrete-block barrier with a channel (1 m across) allowing fish access to each side. Underwater speakers were placed on each side of the opening and an outboard motor noise (broadband sound; 1 Hz to 10 kHz) was broadcast to repel carp that approached within 1 m of the channel. Broadband sound was effective at reducing the number of successful crossings in schools of silver carp, bighead carp, and a combined school. Repulsion rates were 82.4% (silver carp), 93.7% (bighead carp) and 92.2% (combined). This study demonstrates that broadband sound is effective in deterring carp and could be used as a barrier in an integrated pest management system.