A UAV-based survey by the Wildlife Institute of India (WII) and the Tamil Nadu Forest Department has estimated 270 dugongs in Tamil Nadu waters: 158 in Palk Bay and 112 in the Gulf of Mannar, now India's largest viable dugong population. It is the first systematic aerial estimate in the region; interview-based estimates in 2012-13 had suggested about 175 animals. The rise is credited to WII's Dugong Recovery Programme funded through CAMPA. A Dugong Conservation Reserve covering 448 sq km of core habitat in Palk Bay has also been notified. Surveys used fixed 3 km transects, so animals in deeper waters may have been missed.