A long-term ecological disaster is in the making in the Sundarbans because the manual clean-up method being employed in the Sela River oil spill is further contaminating the forest floor, experts said.
The Forest Department and Bangladesh Inland Water Transport Authority (BIWTA) put local people to manually scoop up the spilled furnace oil four days ago.
Ecology and biodiversity researcher Pavel Partha, currently visiting the site of the oil spill, told the Dhaka Tribune that clean-up crews’ wading and tramping were causing oil to be mixed into the forest floor’s muddy soil.
“The photosynthesis of primary food producers like Phytoplankton and Zoo-plankton will be badly affected by oil entering into the mud, and will ultimately destroy the primary level of the mangrove ecosystem’s food chain,” he said.
The seeds of plants such as the Sundari, Goran, Gewa and Kewra will probably not sprout because of disruptions to respiration and evaporation caused by the oil, he said.
A study titled “Oil-spill Impact on Mangrove Forest Sundarbans” conducted by the Asian Development Bank and the Bangladesh government in 2002 said the regeneration of mangrove forest plants is very sensitive to contamination by oil.
“They are sensitive to oil partly because oil films on the breathing roots inhibit the supply of oxygen to the underground root systems. Sundari species, in particular, are more vulnerable than other species of flora in the forest,” the report said.
The Dhaka Tribune found that the Forest Department was making things worse for the environment by deliberately shovelling soil over oil-mixed mud to cover it up.
A forest guard in the Andharmanik area, speaking on condition of anonymity, said the cover-up of the oil slick was being done so that foreign tourists would not see the contamination.
Oil tanker Southern Star 7 went down eight days ago with 358,000 litres of furnace oil in its six holds, after being rammed from behind by empty oil tanker Total Cargo on the Sela River.
The accident site, in the Mrigamari forest of the Sundarbans, is a dolphin sanctuary.
On Thursday, forty-eight hours after the oil spill began, naval vessel Kandari 10 arrived on the scene to contain the slick with dispersant, but was stopped from using the chemicals by the Forest Department over fears that the fragile mangrove ecosystem might be damaged.
Residents of the area, pressed into service as clean-up crews, have reportedly lost interest in the effort after forest officials allegedly failed to pay them their dues.
On Saturday, the forest department engaged 200 day-labourers and 100 boats to manually scoop up the oil slick.
On Friday, government authorities urged local residents to collect the floating oil saying that Padma Oil Company would purchase it at Tk30 per litre.
Roughly 43,000 litres of oil have been retrieved manually as of yesterday.
Divisional Forest Officer of Sundarbans East Zone Amir Hossain Chowdhury said just 50,000 litres of oil would likely be collected in this way because the rest will disperse with the current or get mixed into the mud.
The sunken oil tanker was salvaged on Thursday morning with two undamaged holds containing around 100,000 litres of furnace oil.