Monitoring tourism schooners observing estuarine dolphins ( Sotalia guianensis ) in the Estuarine Complex of Cananéia, south‐east Brazil

1. Surveys were carried out between December 2004 and March 2006 on board tourism schooners to detect possible impacts due to tourist activities on estuarine dolphins ( Sotalia guianensis ) in the Estuarine Complex of Cananéia. 2. The estuarine dolphins exhibited different reactions according to the different periods of time that the boats remained close to them: the longer the period, the estuarine dolphins reacted less negatively, and for periods between 2 and 30 min, more positive reactions were observed. 3. Estuarine dolphin reactions also varied according to the different procedures followed by the skippers. The approach methods considered ‘correct’ resulted in a positive reaction from 97% of the animals encountered and 100% of occasions where there were no apparent reactions. 4. Direct approaches to within less than 50 m were responsible for a large number of negative reactions from the estuarine dolphins. Procedures classified as ‘chasing’ and ‘direct approach with no intention of stopping’ had a 100% negative reaction. If the skippers used a correct approach, estuarine dolphins reacted positively or did not show any reaction. Copyright © 2009 John Wiley & Sons, Ltd.