New sanctuaries declared for Asia's freshwater dolphins

Jeremy Hance
February 15, 2012

Ganges River dolphin in the Sundarbans. Photo by: Rubaiyat Mansur.
Ganges River dolphin in the Sundarbans. Photo by: Rubaiyat Mansur.

Bangladesh has declared three new sanctuaries to help protect the south Asian river dolphin (Platanista gangetica) in the Sundarbans, the world's largest mangrove forest. Split into two subspecies, the Ganges River dolphin (Platanista gangetica gangetica) and the Irrawaddy River dolphin (Platanista gangetica minor), the new sanctuaries will benefit both. Listed as Endangered by the IUCN Red List, the south Asian freshwater dolphin has disappeared from much of its habitat. Already Asia has its other freshwater dolphin species: the baiji (Lipotes vexillifer) was declared functionally extinct into 2006 after a survey of the Yangtze River failed to find a single individual.

"Declaration of these Wildlife Sanctuaries is an essential first step in protecting Ganges River and Irrawaddy dolphins in Bangladesh," Brian D. Smith, Director of the Wildlife Conservation Society's (WCS) Asian Freshwater and Coastal Cetacean Program, said in a press release. "As biological indicators of ecosystem-level impacts, freshwater dolphins can inform adaptive human-wildlife management to cope with climate change suggesting a broader potential for conservation and sustainable development."

Smith and co-authors with the Bangladesh Forest Department wrote a study for Oryx in 2010 that led to the proposal of the three new sanctuaries. The protected areas span 19.4 miles (31.4 kilometers) of channels in the Sundarbans.

The south Asian river dolphin faces a wide-variety of threats including dam projects, drowning as by-catch, pollution, prey loss due to overfishing, changes in salinity levels from rising seas, and in some cases targeted hunting. Many of these same threats pushed the baiji to extinction. However, the south Asian river dolphin may have a better chance to survive in the long run: in 2009, WCS announced the discovery of 6,000 Irrawaddy dolphins surviving in Bangladesh, the biggest population known to date. One of the keys to saving the species will be working with local communities.

"The wildlife sanctuaries will be used as a natural laboratory for developing management practices that balance wildlife conservation with the resource demands of a large and growing human population," explains Tapan Kumar Dey with the Forest Department.

The new sanctuaries will also benefit other endangered species such as the northern river terrapin (Batagur baska), a river turtle listed as Critically Endangered; the masked finfoot (Heliopais personata), a freshwater bird listed as Endangered; and the oriental small-clawed otter (Aonyx cinerea), listed as Vulnerable.

Ganges river dolphin. Photo by: Zahangor Alom.
Ganges river dolphin. Photo by: Zahangor Alom.

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Jeremy Hance
mongabay.com (February 15, 2012).

New sanctuaries declared for Asia's freshwater dolphins.