Current address: Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, Florida 34236, U. S. A.
EFFECTS OF WATERCRAFT NOISE ON THE ACOUSTIC BEHAVIOR OF BOTTLENOSE DOLPHINS, TURSIOPS TRUNCATUS, IN SARASOTA BAY, FLORIDA
Article first published online: 26 AUG 2006
Marine Mammal Science
Volume 20, Issue 4, pages 709–725, October 2004
How to Cite
Buckstaff, K. C. (2004), EFFECTS OF WATERCRAFT NOISE ON THE ACOUSTIC BEHAVIOR OF BOTTLENOSE DOLPHINS, TURSIOPS TRUNCATUS, IN SARASOTA BAY, FLORIDA. Marine Mammal Science, 20: 709–725. doi: 10.1111/j.1748-7692.2004.tb01189.x
- Issue published online: 26 AUG 2006
- Article first published online: 26 AUG 2006
- Received: 14 July 2003 Accepted: 7 April 2004
- bottlenose dolphin;
- Tursiops truncatus;
- acoustic communication;
- disturbance response;
- received level;
Watercraft may provide the greatest source of anthropogenic noise for bottlenose dolphins living in coastal waters. A resident community of about 140 individuals near Sarasota, Florida, are exposed to a vessel passing within 100 m approximately every six minutes during daylight hours. I investigated the circumstances under which watercraft traffic may impact the acoustic behavior of this community, specifically looking for short-term changes in whistle frequency range, duration, and rate of production. To analyze whistles and received watercraft noise levels, acoustic recordings were made using two hydrophones towed from an observation vessel during focal animal follows of 14 individual dolphins. The duration and frequency range of signature whistles did not change significantly relative to vessel approaches. However, dolphins whistled significantly more often at the onset of approaches compared to during and after vessel approaches. Whistle rate was also significantly greater at the onset of a vessel approach than when no vessels were present. Increased whistle repetition as watercraft approach may simply reflect heightened arousal, an increased motivation for animals to come closer together, with whistles functioning to promote reunions. It may also be an effective way to compensate for signal masking, maintaining communication in a noisy environment.