A Gangetic dolphin (Platanista gangetica) was found dead today in Halda River of Chattogram's Raozan upazila.

At seven feet one inch in length and weighing around kilogrammes, it is the biggest of its kind to be found dead in the river so far.

The dolphin's body was recovered around 11:30am from the river at Urirchar area in the upazila.

This is twenty-fifth dolphin found dead in Halda River since 2017, Dr Manzoorul Kibria, an eminent Halda researcher and a professor of zoology at Chattogram University, said.

"The dolphin seemed to have died around twenty-four hours ago. Its mouth was caught in a fishing net," Dr Manzoorul Kibria told The Daily Star this noon.

"This clearly indicates that the mammal died after being entangled in illegal fishing net."

Junayed Kabir Sohag, upazila nirbahi officer of Raozan, told The Daily Star that they rushed to the spot on information, recovered the dolphin and buried it with the help of locals.

"How it died will be revealed after talking to the experts. We are trying to find out what caused its death and who are involved in such illegal activities," the UNO said.

Five days ago the High Court formed a committee to protect the dolphins of Halda River.

The HC committee tasked with protecting the biodiversity, brood fish and dolphins of the river is headed by deputy commissioner of Chattogram while its member secretary will be the divisional forest officer (wildlife and nature conservation) of the forest department.

Abu Naser Md Yeasin Neyaz, divisional forest officer (wildlife and nature conservation) of Chattogram forest circle, told The Daily Star that they talked to the local public representatives on how to create a roadmap to raise awareness in this regard among people living adjacent to Halda River.

"It is very tough to stop the laying of fishing net in the river until locals come forward and they are made aware of the importance of the river," the official said.