Bihar will commission a survey on October 5 to study the condition of Gangetic dolphins in the 525-km stretch of the river between Chausa (Buxar) in the west and Manihari (Katihar) in the east.

The Wildlife Institute of India (WII), Dehradun, has been roped in for conducting the year-long survey.

The state observes October 5 as Dolphin Day and the practice was started in 2012 to make people aware of the importance of the aquatic mammal in the river ecosystem.

Bihar is home to around half of the estimated 3,000 dolphin population in the country. The Gangetic dolphin has been kept under Schedule I of the Indian Wildlife (Protection) Act and has been declared endangered by the International Union for Conservation of Nature (IUCN) as well.

Bihar also boasts of the credit for convincing the then central government to declare the Gangetic dolphin as the national aquatic animal of the country. The formal announcement in this regard was made in the first meeting of the National Ganga River Basin Authority (NGRBA) chaired by then Prime Minister Manmohan Singh on October 5, 2009.

One of the major threats which dolphins face in Bihar is from fishermen, who allegedly kill the mammals for its fat, which is used as a prey to catch fish.

Principal chief conservator of forest D.K. Shukla said: 'Apart from doing the population estimate of the dolphins, the scope of the study also includes things such as the behaviour of the aquatic animal and impact of river pollution on them among other related things.'

Chief minister Nitish Kumar is likely to formally commission the study programme, which would be held amid Wildlife Week celebrations from October 2 to 8.

Shukla said the WII will provide experts in the field of dolphins to conduct the study and it would also give an authentic figure about the actual number of the aquatic animal.

He said the outcome of the study would be of special importance for the environment and forest department as it would help in making a comprehensive plan to take the necessary steps required for protection of the animal, including the habitat improvement. He added that the action plan based on the outcome of the study would be made after consulting experts in the field.

Dolphin expert R.K. Sinha said: 'I am not aware of the details of the scope of the study hence it is tough to comment on the initiative at this stage.' He has conducted several studies on the condition of Gangetic dolphins in the past and is considered an authority on the subject.