Preliminary exploration for effects of sound stimulus on the movement behavior of Litopenaeus vannamei

As one of the most alarming underwater noises today, pile driving noise is the only anthropogenic sound source other than explosives that has caused the death of fish , according to the available literature. The present study explored the effects of simulated pile driving noise on the movement behavior of Litopenaeus vannamei. The experiments were conducted in a tank equipped with DSG and recording apparatus. During the experimental phase, ten individuals of L. vannamei were allocated equally to control and test groups. The test group were exposed to a drubbing noise (178dB_peak re 1uPa) for 10 min. By comparing the time-frequency characteristics, we found that the drubing noise used in this study had a good simulation result for representing shallow water pile driving noise at 200m from the source, which in this case was generated from a 2m diameter steel pile (SL_peak=228.4dB re 1uPa). Results showed that exposure under the simulated pile driving noise caused a significant increase in motility of L. vannamei, accompanied with them keeping away from the sound source, and gathering together and swimming to the water surface. The speeds and total movement distances between test and control group varied significantly (P values were 0.013 and 0.011, respectively). What is more, the results indicated that the pile driving noise (SL_peak=228.4dB re 1uPa) could have an effect on the movement behavior of L. vannamei within 200 m from the sound source, which offered an indication for evaluating noise effects.