Effect of low-frequency under-water noise on the feeding behavior and growth of red sea bream Pagrus major

Abstract

The effect of low-frequency noise on the feeding and growth of 0+ year red sea bream Pagrus major was examined. Four groups (50 fish/group) of fish were reared in separate 600 L circular tanks and fed using self-feeders for 55 days. During day 20 to day 38, each group was exposed to one of four different sound conditions (100 Hz pure tone emitted from underwater speaker system at output sound pressure levels of 100, 120 and 140 dB re 1 μPa @1 m, or ambient noise only). Low-frequency noise exposure did not affect feeding rhythm, feed intake and growth performance. However, 140 dB group fish showed strong startle response at onset of low-frequency noise exposure, and did not stay near underwater speaker through out the low-frequency noise exposure period.