Aversiveness of sound in marine mammals : psycho-physiological basis, behavioural correlates and potential applications

Marine mammals--Effect of sound on;Marine mammals--Effect of noise on;Underwater acoustics

Götz, Thomas ; Janik, Vincent ; Janik, Vincent

University:University of St Andrews

Department:Research Centres and Institutes

关键词: Marine mammals--Effect of sound on;    Marine mammals--Effect of noise on;    Underwater acoustics;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/848/Thomas%20Goetz%20PhD%20thesis.pdf?sequence=3&isAllowed=y

来源: DR-NTU

【 摘 要 】

Understanding what psycho-physiological and behavioural factors influenceaversiveness of sound in marine mammals is important for conservation and practicalapplications. The aim of this study was to determine predictors for impact ofanthropogenic noise and to develop a target-specific predator deterrence system foruse on fish farms. Three classes of stimuli were tested: 1.) grey seal underwatercommunication calls expected to be used in territorial defence, 2.) high duty-cyclemoderately loud artificial sounds (some of which were based on models ofunpleasantness for humans), 3.) brief, intense pulses designed to elicit the acousticstartle reflex.Communication calls had no deterrence effect but instead caused attractionresponses. Tests with high duty-cycle artificial sounds showed that food-motivatedanimals habituate quickly, although sound exposure caused subtle changes in divingpatterns over a longer time. Field trials using the same stimuli were used todetermine avoidance thresholds but also indicated that sound features like‘roughness’ play a role. The startle eliciting stimuli, however, had the most dramaticeffects. To this stimulus most seals exhibited rapid flight responses, hauled out,sensitised and showed signs of fear conditioning. Startle thresholds were found to be80-85 dB above the assumed hearing threshold. The data showed that startlethresholds are a crucial predictor for the occurrence of strong avoidance behaviourand suggests that the startle response evolved to increase an animal’s propensity forflight. Finally, a prototype predator deterrence system based on the startle soundswas developed to repel seals whilst not affecting toothed whales. In fish farm trials,seals were deterred at close ranges but local abundance of cetaceans did notchange showing that it is possible to cause differential responses between speciesbased on differences in their audiograms.The results are used to develop noise exposure criteria and to elucidate acousticparameters that can be used to predict responses to anthropogenic noise.