The dolphins are among the world's most endangered mammals (Photo: Rubaiyat Mansur Mowgli) |
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Bangladeshis declaring three areas in the southern Sundarbans mangrove forest as dolphinsanctuaries to protect freshwater dolphins, officials say.
Conservationistssay the mangrove forest is the only place in the world where the Ganges riverdolphins and Irrawaddy dolphins are found.
Thesedolphins are among the world's most endangered mammals.
Fishermennormally do not target them, but the animals get entangled in fishing nets anddrown.
They arealso threatened by rising salinity levels and pollution.
"Wehave decided to declare Dhangmari, Chandpai and Dudhmukhi areas of easternSundarbans as dolphin sanctuaries so that these mammals can survive in a safeenvironment," Tapan Kumar Dey, a senior wildlife conservation official,told the BBC.
He said thethree water segments were identified as dolphin hotspots by the WildlifeConservation Society's Bangladesh Cetacean Diversity Project (BCDP), which hasbeen doing research in Bangladesh.
'Clearlydemarcated'
Mr Dey saidan official notification on establishing the sanctuaries will be issued by theministry of environment soon.
"Thewaterways in these areas will be clearly demarcated and there will besignpostings so that local fishermen will not venture into this region forfishing," Mr Dey said.
Environmentalistssay the diverse aquatic ecosystem of the Sundarbans support an impressivevariety of cetaceans - whales, dolphins and porpoises.
WhileGanges river dolphins find safe haven in the upper regions of Sundarbans,Irrawaddy dolphins thrive in the southern parts, which are closer to the Bay ofBengal.
Thedecision by the forest department coincided with a new survey by the BCDPwhich, apart from freshwater dolphins, also reported sightings of the finlessporpoises and an Indo-Pacific humpback dolphin in western Sundarbans.
These twocetacean species, which are normally found along the coast, migrate upriver inSundarbans mostly during winter, when the salinity level is high. They go backafter fresh water starts flowing into the rivers.
Thenine-day survey was conducted in the western part of Sundarbans mangroveforests earlier this month.
"Thisyear we encountered many of them during the recent survey, soon after the rainswhen the salinity level is low. Their presence in this region at this time maybe an indication of the rising salinity level," Rubaiyat Mansur Mowgli,principal researcher of the BCDP said.
"Ourpreliminary results indicate that there is a high density of dolphin populationin western Sundarbans as well and some areas there might also be identified asdolphin hotspots," Mr Mowgli said,
However, hewarned that the identification of new dolphin hotspots does not mean theanimals are thriving in Sundarbans.
"Decliningfreshwater supplies and rising sea levels due to global climate change areaffecting the dolphin population," Mr Mowgli said.
Two yearsago, researchers found that there were nearly 6,000 Irrawaddy dolphins - whichare related to orcas or killer whales - in the waterways of Sundarbans mangroveforests and the nearby coastal waters of the Bay of Bengal.