Irrawaddy & Gangetic dolphins protected by three new sanctuaries in Bangladesh

Mangrove forests will provide a global safety net

February 2012: Bangladesh has created three new wildlife sanctuaries for endangered freshwater dolphins in the world's largest mangrove ecosystem – the Sundarbans, according to the Wildlife Conservation Society (WCS), whose conservation work helped pinpoint the locations of the protected areas.

DISAPPEARING: The Ganges River dolphin. Picture: WCS

The sanctuaries, which were officially declared at the end of last month, will protect the last two remaining species of freshwater dolphins in Asia: the Ganges River dolphin and the Irrawaddy dolphin. Although there is no global population estimate for either species, both have disappeared from major portions of their range. However, there are sustainable populations of both species in the Sundarbans, which may now serve as a global safety net for preventing their extinction.

Vital first step towards protecting dolphins
The three wildlife sanctuaries safeguard 19.4 miles of channels with a total area of 4.1 sq miles. The locations and sizes of the sanctuaries in the Sundarbans were determined according to a study conducted by WCS and Bangladesh Forest Department. The study found that the habitat of Ganges River and Irrawaddy dolphins were clumped in waterways where human activities are most intense.

‘Declaration of these wildlife sanctuaries is an essential first step in protecting Ganges River and Irrawaddy dolphins in Bangladesh,' said Brian D Smith, director of the WCS's Asian Freshwater and Coastal Cetacean programme.

‘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.'

Dr Tapan Kumar Dey, conservator of Bangladesh's Forests, Wildlife, Forest department, said: ‘A critical component will be to engage local human 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.'

Yangtze river dolphin already wiped out
The dolphins are threatened by fatal entanglements in fishing gear, depletion of their prey from the enormous bycatch of fish and crustaceans in fine-mesh nets used to catch fry for shrimp farming, and increasing salinity and sedimentation caused by rising sea levels and changes in the availability of upstream freshwater flow.

News of the declared sanctuaries is particularly welcome considering the recent extinction of the Yangtze River dolphin whose last confirmed sighting was in 2002. Fatal entanglement in nets and habitat degradation killed off this species after having survived in China's Yangtze River for more than 10 million years.

Bangladesh is a cetacean hotspot
Freshwater dolphins are among the most threatened wildlife on earth because their habitat is highly impacted by human activities, including dam construction and unsustainable fisheries. In addition to conserving globally important populations of freshwater dolphins, the new wildlife sanctuaries in the Sundarbans will provide protection for other threatened aquatic wildlife including the river terrapin, masked finfoot, and small-clawed otter.

Bangladesh has been recognized as a cetacean hotspot. In April 2009, the WCS announced the discovery of the world's largest population of nearly 6,000 Irrawaddy dolphins in the country. A portion of this population shares habitat with the endangered Ganges river dolphin, whose range extends all the way upstream to the shadow of the Himalayas in Nepal.

This month the WCS, through its Bangladesh Cetacean Diversity Project, will bring a boat-based dolphin exhibition called the Shushuk Mela to local communities bordering the mangrove forest. This month-long travelling exhibition will raise awareness about the new wildlife sanctuaries and engage local fishermen and other community members in discussions on adaptive management needed to ensure human-dolphin coexistence.