About 90 per cent of fishes and most of other aquatic lives that once made the waters of the Teesta, Dharla and Brahmaputra rivers their abode have vanished over the past three decades, according to an estimate by the Rangpur divisional office of the Department of Fisheries.
The dramatic decline of aquatic lives in the rivers, which have now transformed into dozens of narrow localised streams crisscrossing the country’s northern region, was caused by a sharp fall in the water flow of the rivers because of interruptions in the upstream in India, said river experts and government fisheries officers.
Especially, the Teesta is in a very bad shape for it has a flow only between October and January, representing the period when India releases water from the Gajoldoba Barrage, according to the Water Development Board.
The rest of the year, especially between March and May, the Teesta lies completely dried up, with people walking across the river on foot, except those occasions when India arbitrarily releases water from the barrage following a heavy rain.
‘In the latest fish census last year, we detected only 27 fish species in the Teesta, Dharla and Brahmaputra,’ said Saifuddin Yahiya, deputy director, Department of Fisheries, Rangpur division.
The DoF carries out a fish census every rainy season at the height of water flow in the rivers — which usually falls in October.
In 1988, the DoF official said, as many as 267 fish species had been found in the rivers.
‘We fear that the species we still have will be lost over the next few years,’ said Yahiya.
The fish species that could still be found during the peak rainy season last year included bairali,tengna, kalabush, koya, balia, shole, boal, puti, chanda, poa, chingri, pabda, mithai, gorai and chad gobda.
The number of fishermen dropped to just about 3,000 now from 17,000 in 2010 following the decline of fish species, officials at the fisheries department said.
In 1988, sweet-water dolphins and crocodiles were among 317 other species of aquatic lives found in the rivers, the fisheries department said, adding that these species are mostly extinct.
The fear that the last surviving aquatic lives in the rivers will be lost soon deepened after Indian media recently reported West Bengal’s plan of withdrawing even more water from the Teesta by digging two more canals.
‘Arbitrary withdrawal of water is leading to rapid desertification of the Rangpur area,’ said Tuhin Wadud, a river researcher, who also teaches Bangla at Begum Rokeya University in Rangpur.
‘People will soon forget that there was a river named Teesta, unless the equal sharing of the river water is ensured,’ said Tuhin, director, Riverine People, a non-government organisation.
After originating in the Himalays, the 315-km-long Teesta flows 165 km inside Bangladesh before merging with the Brahmaputra at Chilmari in Kurigram.
The Teesta flows through the Lalmonirhat, Nilphamari, Rangpur and Gaibandha districts.
Water Development Board officials say that the water flow the Teesta gets, downstream the Teesta Barrage at Gajoldoba in West Bengal, is mostly natural as India does not release any water through the barrage during the lean months.
The WDB officials said that four canals were arbitrarily withdrawing water from the Teesta in West Bengal before the latest announcement came from the state government about digging two more canals to serve some one lakh farmers in Jalpaiguri and Cooch Behar.
On March 4, Indian newspaper The Telegraph reported the transfer of 1,000 acres of land to the irrigation ministry of West Bengal to excavate two new canals for withdrawing water from the Teesta and the Jaldhaka.
According to Indian media reports, there are 42 dams built on the Teesta starting from Sikkim.
Every year, West Bengal channels about 10 per cent of the Teesta water to the Mahananda River, said the Third Pole, a multilingual platform disseminating information on the Himalayan watershed and the rivers that originate there, citing 2010 data.
The 13-km-long area upstream the Bangladesh Teesta Barrage inside gets some water while the rest of the river suffers an acute water shortage most of the time, according to the WDB.
‘Water is river’s life. Rivers die without water and so die nature and people,’ said Mahbubur Rahman, WDB additional chief engineer, north zone.
Since January, WDB officials said, the Teesta Barrage in Bangladesh recorded water flow between 1,200 and 1,500 cusecs against the need for 3,500 cusecs.
Principal Nazrul Islam, president, Rangpur division, Teesta Bachao, Nodi Bachao Sangram Parishad, feared that hundreds of thousands would become jobless and face food crisis if the Teesta could not be saved.
The northern region is dubbed Bangladesh’s rice basket as the region grows boro rice, the main food crop of the country.
Boro growers face increased challenges due to both water shortages and excesses because of India’s arbitrary withdrawal and release of water in the Teesta, said Principal Nazrul.
Flash floods destroy standing crops in the northern region when India opens the Gajoldoba Barrage without any warning, causing flash floods.
The Gajoldoba Barrage project was launched in 1975 with a plan to irrigate 9.22 lakh hectares of agricultural land in the North Bengal region of West Bengal with the plan to route water from the Teesta through canals on either bank of the river, reported the Telegraph.
The project now irrigates 1.04 lakh hectares.
The Telegraph also reported that West Bengal also decided in principle to set up three hydropower projects in Darjeeling hills, with the likelihood of two of the projects reducing water volume in the transboundary river Teesta.