New Delhi, May 3 (IANS) Looking towards the conservation of Indus Dolphins -- one of the world's rarest mammals -- Punjab government along with WWF-India are conducting a first organised census, officials said on Thursday.

Found only in India and Pakistan, the Indus Dolphins are confined to only 185 km stretch between Talwara and Harike Barrage in India's Beas river in Punjab.

Officials from the Department of Forests and Wildlife Preservation, Punjab and WWF-India are currently working in two teams and will estimate their population over the five-day exercise.

"We are trying to establish their near accurate population as to plan their conservation accordingly. It is the first organised census, previously we had merely spotted them," Kuldeep Kumar, Chief Wildlife Warden, Punjab told IANS.

According to Suresh Babu, Director River Wetland and Water Policy, WWF-India, the most flourishing population of the Indus dolphin, platanista gangetica minor, is found across Pakistan where their numbers are estimated around 1,800 over a stretch of 1,500 km of the Indus river.

In India, a tiny population survives in this small stretch of Beas river. Experts say they were also found in Sutlej decades back, however, river pollution is believed to be a major cause of their extinction from the habitat.

"Dolphins are a key indicator of a river health if a river is healthy the dolphins will be there and if not, we have the example of Sutlej," Suresh Babu told IANS.

According to the International Union for Conservation of Nature (IUCN), construction of critical barrage is associated with the large-scale decline in the area of occupancy, "which have not ceased".

IUCN suspects the population size of the Indus river dolphins has reduced by more than 50 per cent since 1944.

A blind species that communicates through echo like a Bat does, Indus dolphins are one of the seven freshwater dolphins found across the world.