The Gangetic dolphin found in the Brahmaputra and its two tributaries is teetering on the brink of extinction due to loss of space and widespread poaching.
Different surveys conducted in the last 25 years have found a declining population of the Gangetic dolphins in Subansiri river. The Gangetic dolphin is one of the last remaining three dolphin species in the world.
Gangetic dolphin is found in the Brahmaputra along with Ganga, Meghna, Karnaphuli rivers systems of Indian sub-continent. In Assam this dolphin is found in the Brahmaputra and its two tributaries–Kulshi in Kamrup district and Subansiri in Lakhimpur district.
The river Subansiri is the largest tributary (443 km) of the Brahmaputra originating from Purum Peak in Tibet. The river crosses about 143 km in Tibet, then enters Arunachal Pradesh covering 199 kms and finally enters Assam near Gerukamukh of Lakhimpur district.
The river stretches 94 kms from Gerukamukh to Jamugurighat in Lakhimpur district. Red listed by IUCN as endangered mammals, the Gangetic dolphins are found in the areas of Subansiri in four sectors– Katori Chapori to Bodhakora, Bodhakora to Solmari, Solmari to Boroliya and Boroloiya to Silikhaguri.
The dolphins are spotted mostly in the Bodhakora-Solmari and Solmari-Boroliya sectors of the river. But over the years, the Gangetic dolphin, which is the indicator of clean water, has become a rare sight and its visibility in the river is almost nil.
According to a 1993 survey, the river recorded 25 dolphins; in 2005 it had 26 dolphins and in 2008 the number of dolphins in the river was 23.
The declining numbers of the species reflect a gloomy picture of the bio-diversity affected by various factors. The loss of space and widespread poaching including fishing is one of the factors of the vanishing population of this exotic aquatic mammal, said wildlife activists.
Indiscriminate poaching of the dolphins by Gill net and mosquito net for its meat and fats is a major concern for this endangered species.
The Brahmaputra river basin is one of the last remaining refuges of Gangetic dolphins. But the Lower Subansiri Hydro Electrical Power project, which is under construction, is likely to result in declines in the range and or abundance of the Gangetic dolphin population.
It could have cumulative impacts leading to the complete disappearance of the species from the Brahmaputra River and its tributaries, a wildlife activist pointed out.
Aggressive campaign and awareness programme is the need of the hour in order to protect and save Gangetic dolphins of Subansiri in Lakhimpur district.
A Dolphin Yatra was conducted by Gangetic Dolphin Research and Conservation Initiative by Aranyak from March 1 to 7 in 2014 on the riverine areas of Subansiri in Lakhimpur district.
The campaign organized 22 awareness camps for the dolphins in Bodoti, Dohghoria, Bordubichang, Alichiga, Chenimora, Bholukaguri, Jugalpur, Katori Chapori and Mohghuli villages off the Subansiri in Lakhimpur district.