Responses of Blueback Herring to High-Frequency Sound and Implications for Reducing Entrainment at Hydropower Dams

Abstract

Low‐ and high‐frequency sounds were tested as a means of repelling blueback herring Alosa aestivalis in confined‐area and open‐water experiments. Confined‐area tests were performed by analyzing the response of blueback herring in floating net‐pens to sounds differing in frequency, sound pressure levels (SPLs, given in decibels [dB] in reference to l.0 μPa), and pulse width. Highfrequency sounds between 110 and 140 kHz, at SPLs above 180 dB (at 1.0 m from the transducer) and at various pulse widths, elicited statistically significant (P < 0.05) avoidance responses by blueback herring. A reduced response was observed at sound frequencies of 100 and 150 kHz. Low‐frequency sounds between 0.1 and 1 kHz at SPLs of 160–175 dB (at 1.0 m from the transducer) elicited only short‐term startle responses. Field tests were performed at Richard B. Russell Dam (on the Savannah River at the Georgia‐South Carolina border) to evaluate candidate transducers and amplifiers. In field evaluations a single high‐frequency transducer emitting 124.6‐ and 130.9‐kHz sounds at an SPL of 187 or 200 dB (at 1.0 m) partially repelled blueback herring that were approximately 60 m away from the transducer for periods of up to I h. These results suggest that high‐frequency sound may provide an effective and inexpensive method, relative to structural measures, for reducing entrainment of blueback herring at hydropower stations.

Effects of Ultrasonic Frequencies on Schooling Behavior of American Shad (Alosa sapidissima)

“…Steam or hydro-powered electricity generating stations often entrain and kill fish and can therefore have a negative impact on fish populations. High frequency sounds emitted by transducers used at dams have been shown to reduce the entrainment of A. aestivalis and A. pseudoharengus for short periods of time [9]. Applying high intensity pulsed ultrasound (frequencies from 110-140kHz at power levels above 180dB) has been shown to repel several species of Clupeiformes, including A. sapidissima, A. aestivalis and A. pseudoharengus, from cold water intakes used in power plants.…”

Ultrasound detection in the Gulf menhaden requires gas-filled bullae and an intact lateral line

“…However, in the early 1990s it was reported that ultrasonic sonar pulses were an efficient way of repelling certain clupeiform fish species from the water intakes of power plants (Dunning et al, 1992;Nestler et al, 1992). It was not clear whether the fish responded to the ultrasonic component of the sonar or whether they responded to low frequency by-products.…”

Behavioral Responses to Underwater Sound in the Small Benthic Octopus Octopus ocellatus

“…In fisheries, sound has been applied to drive fishes into nets, and attracting fishes using sound has been tried [2][3][4] . It is also possible to keep fish away from a certain area (e.g., a water intake opening of a power plant) using sound [5][6][7][8][9] . Moreover, the strong ability of associate learning in fish allows conditioning procedures to be applied for fish aggregations using sound in aquaculture 10).…”