REACTIONS OF CAPTIVE HARBOR PORPOISES (PHOCOENA PHOCOENA) TO PINGER‐LIKE SOUNDS

摘要: Pingers on gill nets can reduce bycatch of harbor porpoises. If porpoises habituate to pingers, the effect may be reduced or lost. Two captive were exposed three sound types. All sounds in frequency band from 100 kHz 140 kHz, 200 ms long, and presented once per 4 s. The source level was 153 dB re 1 μPa RMS at m. Each session consisted a 10-min presound, 5-min sound, postsound period. Behavior recorded video dataloggers placed dorsal fin one animal. loggers heart rate, swimming speed, dive duration, depth. animals responded most strongly initial presentations sound. Surface time decreased, rate dropped below normal bradycardia, echolocation activity decreased. reactions both diminished rapidly following sessions. Should waning responsiveness apply wild animals, adapt but still avoid nets, increase after some time. success long-term use pingers then depend variety rates exposure.