Behavioral alterations in the gray dolphin Sotalia guianensis (Gervais, 1953) caused by sea traffi

Abstract

Behavioral responses by Sotalia guianensis dolphins in the presence of touristic sea traffic in the bay of Curral, Pipa-RN, Brazil, were measured. The dolphins changed their behavior when boats were closer than 100 meters. The main behavioral alterations were that the dolphins remained submerged for longer and that they formed a more cohesive group as the boats came closer. Although we concluded that the approach of the boats changed the dolphins’ behavioral pattern, we do not know what aspects of the boats caused the avoidance. We believe that the noise of the boats is probably responsible for repelling the animals.

Keywords

• behavioral alteration
• gray dolphin
• underwater noise