Meeting Abstract
Many animals rely on sound for important cues about their environment, yet there is an increasing awareness that anthropogenic sound may be threatening the ability of individuals to communicate. For the oyster toadfish, Opsanus tau, vocal communication and sound detection are critical for reproductive success, however little is known about how they may respond to changes in their acoustic environment. Passive acoustic monitoring was conducted in a small harbour (Eel Pond, MA, USA) to pinpoint the location of male oyster toadfish producing mating vocalizations, termed boatwhistles, to attract females. Significantly less vocalizations were detected following exposure to continuous vessel sound (100 – 12,000 Hz, source level 130 dB re 1 μPa), suggesting individuals changed their vocal behavior in response to anthropogenic activity. To investigate the physiological effects of anthropogenic sound, toadfish auditory sensitivity was also tested in laboratory experiments using the auditory evoked potential technique, before and after exposure to 1 hour of vessel sound. Auditory sensitivity (100 – 500 Hz) significantly decreased following exposure to vessel sound and did not return to baseline levels until 6 days after. This study highlights that vessel sound influences both the behaviour and physiology of aquatic life. The masking effect of overlapping frequencies from continuous vessel sound, and temporary threshold shifts in auditory sensitivity, is suggested to reduce communication space: the ability to detect, perceive and response to conspecifics and ultimately lead to a failure in mate attraction and detection.
