Irrawaddy Dolphins: Freshwater Species of the Week

Photo: Irrawaddy dolphin
A rare Irrawaddy dolphin spotted in Indonesian waters. David Dove / WWF Greater Mekong


This is the first post in a new series that celebrates the extraordinary diversity of freshwater ecosystems around the world. Every Friday, we’ll present a new species, and examine what each can teach us about the importance of preserving, and in some cases restoring, freshwater habitats.

This week, we take a look at the Irrawaddy dolphin (Orcaella brevirostris), a rare species of freshwater dolphin that is highly vulnerable to extinction due to pollution, dams, and diversions in the rivers it calls home.

This week, the World Wildlife Fund reported that Irrawaddy dolphins have been seen for the first time in West Kalimantan, on the Indonesian island Borneo. WWF-Indonesia and the Regional Office for Marine, Coastal & Resources Management Pontianak  (BPSPL) saw the freshwater cetaceans while conducting a study in the narrow straits and coastal waters of the Kubu Raya and Kayong Utara regencies in the western part of Borneo.

Albertus Tjiu, WWF-Indonesia’s Conservation Biologist, said, “The results of this study indicate the importance of protecting the dolphins’ habitat, from the origins of the rivers in the Heart of Borneo, to the lower rivers of the island, including waterways of Batu Ampar mangroves and nypah forests, the narrow straits and the coastal areas of Kubu Raya, West Kalimantan.”

The scientists also saw Indo-Pacific humpback dolphins in the area.

Tjiu warns that the area is seeing increasing charcoal production, threatening the flooded mangrove forests that serve as key habitat to the Irrawaddy dolphin. WWF is calling on producers to avoid deforesting sensitive areas.

According to WWF, there are about 6,000 Irrawaddy dolphins left in the wild, with about 5,800 of them living in Bangladesh. The remainder are scattered throughout Southeast Asia. The species is officially listed as “vulnerable” by the IUCN, although it is listed as critically endangered locally in some areas, including the Mekong River, the Ayeyawardi River, and the Mahakam River in East Kalimantan.

Intelligent and playful, river dolphins are charismatic animals. But they are unlikely to survive in large numbers unless countries get serious about protecting and restoring river habitats.


Brian Clark Howard is a writer and editor with He was formerly an editor at The Daily Green and E/The Environmental Magazine and has contributed to many publications, including,,,, Yahoo!, MSN and elsewhere. His latest book, with Kevin Shea, is Build Your Own Small Wind Power System.