6,000 rare, large river dolphins found in Bangladesh

Washington, April 1 (ANI): Conservationists have reported a previously unknown population of Irrawaddy dolphins in Bangladesh, which would give scientists "great hope" for the survival of the rare species.

According to a report in National Geographic News, a research team estimated that 6,000 Irrawaddy dolphins thrive in the country's Sundarbans mangrove forests and nearby waters of the Bay of Bengal.

The group is the largest ever found.

Previously, scattered groups of only about a hundred Irrawaddy dolphins each had been found throughout the dolphin's Southeast Asian habitat, which stretches from the mouths of rivers feeding the Bay of Bengal across open waters to Indonesia.

The species' total worldwide population is unknown.

"That's why this is so exciting," said Howard Rosenbaum, head of the ocean giants research program at the Wildlife Conservation Society (WCS), the conservation group that made the discovery.

"Here you have this area where we found nearly 6,000 animals-it gives us hope for protecting the entire species and this really important habitat," he added.

Few marine-mammal biologists had previously explored the diverse water ecosystem where the new dolphin group was found, which ranges from freshwater mangroves to brackish water to deep ocean canyons in just a small area.

Because the 6.5- to 8-foot-long (2- to 2.5-meter-long) mammals surface only occasionally, researchers used a transect method to gather data about the population.

The team steered a boat along a straight line, noting any dolphin sightings along each run. A wider population estimate was then made from that data.

According to Rosenbaum, six thousand is a "tremendous amount" of individuals for the species-listed as vulnerable on the International Union for Conservation of Nature's Red List.

"But, it doesn't mean we're out of the woods yet," he said.

"To know that there's a very large population elsewhere is quite a relief," said Dekila Chungyalpa, director of the Mekong River program for WWF-US.

But, she added, "just because we're finding these wonderful numbers doesn't mean the urgency is any less strong." (ANI)