Spinner Dolphin

Spinner dolphins were the most numerous cetacean in the offshore survey of Sri Lankan waters. On research cruises around the island from March to June 2003, four groups totalled about 605 animals, more than any other species, and the largest group was an estimated 500 (de Vos et al. 2012).

The same survey found many cetaceans near the submarine canyons off the coast, which are thought to boost productivity, and Sri Lanka's narrow, steep continental shelf brings deep water close to shore (de Vos et al. 2012). Some smaller dolphins, including the common bottlenose, striped and Fraser's dolphins, were in mixed groups. The 2012 national list gives no national category for cetaceans.