Dibrugarh, Oct. 5: A prominent environment group today said construction of mega dams in Arunachal Pradesh and Meghalaya would destroy the habitat of endangered Gangetic dolphin, underscoring the need for a comprehensive study before the projects get experts’ clearance.

The observation by Abdul Wakid, head of the Gangetic Dolphin Research and Conservation Programme of Aaranyak, an NGO, came at a time political parties, including the AGP, organisations like the Krishak Mukti Sangram Samiti and AASU are opposing construction of mega dams in the region without taking into consideration the impact these will have in the downstream areas.

Wakid was addressing a talk organised by Aaranyak in collaboration with the department of zoology, Dibru College.

According to the young researcher, who is also a dolphin expert, the Brahmaputra river system in Assam is considered to be one of the last refuges for the species Platanista gangetica gangetica because of low density of human population in the area compared to areas surrounding the Ganga. Until now, the Brahmaputra has flowed unimpeded by dams.

Construction of large dams on various forerunners and tributaries of the Brahmaputra in Arunachal Pradesh and Meghalaya pose survival threat to the Brahmaputra river dolphins.

“According to our study, among the 168 proposed dams in the Northeast, we have found the Lower Siang, Dibang, Lower Demwe (on the Lohit river), Lower Subansiri and Kulsi dams the most threatening for the survival of the Brahmaputra dolphins,” Wakid said.

The Gangetic river dolphin is one of the four river dolphin species of the world and is found in the Ganga-Brahmaputra-Meghna and Karnaphuli river systems of India, Nepal and Bangladesh.

In the 19th century, dolphins were plentiful across the entire distributional range. However, the range and abundance of this species have sharply declined in the last century and therefore, the IUCN-World Conservation Union recognised it as an endangered species in 1996.

It is estimated that currently there are less than 2,000 of this species globally. The species has been categorised as a Schedule-I Species in India under the Wildlife Protection Act, 1972, because of rapid decline in its number.

The Centre declared it the national aquatic animal in 2009 and Assam declared it state aquatic animal in 2008. In recent surveys conducted in the Brahmaputra river system, Wakid and his team from Aaranyak have recorded the existence of 264 dolphins, including 212 in the Brahmaputra mainstream, 29 dolphins in the Kulsi and 23 in the Subansiri. Construction of the proposed dams may reduce the upstream distribution of dolphins in the rivers and block upstream migration.

It is observed that no detailed study on river dolphin distribution, movements or migration were conducted during the preparation of environmental impact assessment reports for these dams.