Guwahati: The channel linking Dorabeel wetland with the Kulsi river at Kukurmara has nearly dried up, raising serious concerns over the survival of the endangered Gangetic river dolphin.
According to a report by The Assam Tribune, the 700-metre-long channel has seen a sharp decline in water flow velocity, leading to a complete halt in fish migration from the wetland to the Kulsi river. The disruption has put the dolphin population at risk, as the confluence—locally known as Janarmukh—traditionally provides year-round food availability.
The report said dolphins frequent the confluence as fish migrating from Dorabeel become disoriented due to countercurrents, making them easy prey. The site also attracts tourists throughout the year because of regular dolphin sightings.
During the monsoon, the channel reaches a depth of nearly four metres, which normally reduces to about two metres during the lean season. However, the report noted that the channel has now become almost defunct, raising fears over the collapse of fish movement to dolphin habitats. Dorabeel wetland is home to at least 74 fish species, many of which migrate to the Kulsi river through this channel.
Former Gauhati University professor M M Goswami warned that the channel plays a critical role in dolphin conservation and said any disruption would inevitably cause a food crisis for the species. Describing the channel as the lifeline of both the national and state aquatic animal, he stressed the need to ensure uninterrupted water flow.
Goswami also cautioned that both allochthonous and autochthonous sedimentation threaten the channel and said authorities must prevent external sediment deposition to protect the wetland–river linkage.
The report recalled that Dorabeel was among four wetlands scientifically studied between 1977 and 1980 under a North Eastern Council-sponsored project coordinated by Professor S C Dey, with Goswami and the late Bupen Lahaon as members of the research team.
Goswami said dolphins have inhabited the confluence for over four decades due to consistent fish migration from the wetland and added that since fish breeding occurs in Dorabeel, maintaining the connectivity of channels remains essential.
Social activist Manasjyoti Kalita urged collective efforts to protect the channel, saying conservation of natural resources must remain a priority. He noted that dolphin-centric tourism has provided economic benefits to local communities, but unchecked human activity has damaged both conservation efforts and tourism prospects.
Local residents said that the confluence was once a thriving feeding ground for dolphins, but sightings have now dropped sharply, with dolphins rarely seen even once a day due to disrupted fish migration.
Residents further alleged that the channel was blocked with earth for nearly three months to facilitate the movement of earth-laden vehicles, leading to sediment accumulation. They accused unscrupulous traders of obstructing the channel during the lean season to allow dumper and earthmover traffic in violation of environmental laws.
Calling the trend alarming, residents warned that such practices could undo dolphin conservation efforts and stressed the need for sustainable measures to keep the channel open year-round for unhindered fish movement.