Environmental experts and fisheries organisations have flagged a serious threat to the ecology of the Indian Sundarbans due to recent incidents of fly ash-filled barges capsizing and sinking in the Hooghly river.
Two fly ash-filled barges sank on April 9, 2020, within a range of 30 kilometres — one on the Hooghly close to Tangrachar village of Kulpi block in morning; the second on the Muriganga river, that meets the Hooghly near Sagar island, in the afternoon.
On April 18, another barge sank near Kakdwip in the South 24 Paraganas district. Before this, two other fly ash-filled vessels sank in the Hooghly in February and March.
Nearly 100 Bangladeshi barges — each weighing 600-800 tonnes — regularly traverse through Indian waters, about 100 kilometres adjacent to the Indian Sundarbans, taking fly ash from Indian thermal power plants to Bangladesh where the ash is used as raw materials for cement production.
Sounding the alarm
A fishery association wrote to Chief Minister Mamata Banerjee recently, alleging that seeping fuel and fly ash from the sunk vessels threatened the local fishes and other aquatic biodiversity, and in turn, the livelihoods of thousands of fishermen in the area.
The letter was written by Dakhinbanga Motsojibi Federation (DMF) — South Bengal Fisheries Association — on April 20.
The letter said that “the river is getting polluted due to mixing of various toxic elements embedded in fly ash, which, in turn, may endanger those who would be consuming such fishes”.
It said the area fell within the Hilsa sanctuary declared by the government.
“Most of the barges carrying fly ash to Bangladesh are quite old, ill-maintained, not fit for such a long journey and hence often cause accidents. The government should ban plying of these vessels through the Sundarbans, that is an ecologically sensitive area,” Milan Das, DMF secretary, said.
Experts point out that apart from causing river pollution, the toxic chemicals and fuel released due to accidents may also affect the mangroves in the area.
“Once the vessels meet with accidents and get submerged, it is expected that the fly ash will gradually come out and get deposited on the river bed,” Arunava Majumdar, a retired scientist of All India Institute of Hygiene and Public Health, said.
“Gradually, the pollutants within fly ash including heavy metals like lead, chromium, magnesium, zinc, arsenic and others get mixed up with the water and cause damage to both aquatic flora and fauna including fish,” he added.
An official of the Kolkata Port Trust (KPT) said that being of less engine strength; barges often ply slower than the minimum mandated speed of seven knots (about 13 km) per hour, and hence cannot counter any suddenly-occurring adverse situation.
“Moreover, they hardly take an Indian pilot in Indian waters, which is mandatory, and hence face navigational problems,” the expert added.
The KPT, which is the custodian of the river, admits pollution from such accidents but points out that the onus lies with the Inland Waterways Authority of India (IWAI), which regulates the transboundary barge movement.
“We have already taken up the issue with IWAI,” Vinit Kumar, chairman of KPT, told this reporter.
“We have asked the Indian agents of the barges to immediately take care of the issue. But the lockdown situation is perhaps causing delay,” LK Rajak, director IWAI, Kolkata, said.
KPT sources, however, said that normally, the submerged barges were not taken out of the water because of the cost involved, unless they created problem in the navigational channel.