Irrawaddy dolphin - Population & Distribution

Small populations over a large area

Current Population and Distribution
Irrawaddy dolphins are found in the Indo-Pacific, from northeastern Australia in the south, north to the Philippines, and west to northeastern India.

Freshwater subpopulations occur in the river Mahakam of Kalimantan (Indonesian Borneo), the Ayeyarwady (formerly Irrawaddy) of Myanmar (formerly Burma), and the Mekong Delta of Laos, Cambodia, and Vietnam. They are also reported in isolated brackish (saltwater and freshwater) water bodies, such as Chilka Lake in India and Songkhla Lake in Thailand.

There have been serious population declines in parts of Thailand, and in the Mahakam river (Indonesian Borneo) freshwater subpopulations. The latter was classified as Critically Endangered in the IUCN Red List in 2000 after surveys found only a few tens of dolphins in approximately 300 km segment of a river.

In the Philippines, the few Irrawaddy dolphins of Malampaya Sound (Palawan) appear to be geographically isolated from other subpopulations, which could earn that population the status of Critically Endangered. There, the dolphin population is in immediate danger of extirpation due to low numbers, limited range and high mortality. A 2001 survey put their population at 77 individuals over a 133 km² area.