The dolphins in Chambal river have declined by almost one-third - from 98 to 69 - in the last three years and include only 40 adults, 21 adolescents and eight calves, said wildlife officials here.
Though there is a National Chambal Sanctuary to protect the aqua life, little has been done to protect the dolphin from the ever-increasing pollution and rampant poaching mainly responsible for the declining numbers, the officials said.
"Founded in 1979, the sanctuary covers the entire 435-km flow of the Chambal river through Madhya Pradesh, Uttar Pradesh and Rajasthan. It is known for alligators, crocodiles, tortoises and rare Gangetic dolphins," said sanctuary authorities. The sanctuary is co-administered by the three states.
The other inhabitants of the sanctuary include chinkara, sambar, nilgai, hyena, leopard, wolf and wild boar.
Dolphins were first discovered in the Chambal during a 1985 census of alligators but the rare Gangetic dolphins are the sanctuary's main attraction. Known as the Ganges River Dolphins, they are blind but hunted for their meat, said forest department officials.