Common Bottlenose Dolphin

On the 2003 offshore survey, common bottlenose dolphins were sighted twice, about 33 animals in all: a small group off the west coast and a group of 30 near the Basses Submarine Canyon in water 1,000 to 1,800 m deep. Their large size and the depth suggested to the authors that they belonged to the offshore form of the species (de Vos et al. 2012).

The west-coast group was travelling with about 100 striped dolphins, a mixed-species association documented elsewhere in the western Indian Ocean. A group of 30 was somewhat unusual, as most bottlenose dolphins are found in groups of 20 or fewer (Jefferson et al. 2008, as cited by de Vos et al. 2012). Live sightings, strandings and bycatch records show the species has long been common around the island (de Vos et al. 2012).