Illegal sand mining, fishing and stone quarrying in the sanctuary area is killing ghariyals.

Complaint filed in the National Green Tribunal has sought its intervention in the matter.

"Mining of sand banks is destructive for ghariyal population as sand banks are essential for nesting and basking," said applicant and wildlife activist Upamanyu Raju.

Ghariyals lay their eggs under sand beds, illegal sand mining destroys their nests.

Complaint submitted to NGT reads, "sand is extracted for construction works. Local inhabitants are cultivating river banks immediately adjacent to the river and this is causing considerable disturbance to natural habitat of ghariyals."

"Besides, villaers residing along the river are flattening ravines present in the sanctuary for farming."

The 425 kms of the Chambal river was declared a protected area in 1979. The river originates from Kota in Rajasthan, runs through sandy ravines and ends at Bhare in Etawah, where is merges with the Yamuna.

UP has 150 kms of the river sanctuary running along Bah (Agra) and Etawah.

Ghariyals are the major wildlife attractions of the sanctuary.

Illegal fishing is another threat to ghariyals as they get entangled in fishing nets and drown.

Many a times, ghariyals injured by fishing hooks starve to death as they can neither hunt nor eat.

Complaint was filed in September last year.

Sources in UP forest department said NGT is yet to pass any directive, though it has sought responses from the three state governments.

"In fact, UP is the only state which has done things for ghariyal conservation. Nests are protected by way of wire mesh and long iron staves against attacks from jackals, dogs and other animals who dig up the nests to eat eggs," said sources.

Next hearing is scheduled on March 10.

According to 2012-13 census, UP stretch of the sanctuary had 785 ghariyals which is a remarkable increase. There were 307 ghariyals in 2008-09, the number rose to 674 in 2011-12.