The sinking of a coal-laden vessel on Saturday has prompted the government to ban again the operation of all vessels in the Shela River, a dolphin sanctuary in the Sundarbans.

Earlier, it had slapped a ban on the plying of commercial vessels for a month after an oil tanker sank in the river on December 9 in 2014. It, however, reopened the route in January last year, ignoring an outcry from environmentalists.

Even the forest department had protested the lifting of the ban, saying it would pose risk to the biodiversity of the mangrove forest.

The latest prohibition order came from Bangladesh Inland Water Transport Authority (BIWTA) two days after the coal-laden vessel, Seahorse-1, sank in the Sundarbans. 

“The ban has been imposed this morning. It will continue until further notice,” Saidul Islam, divisional forest officer of the Sundarbans (East), told The Daily Star yesterday.

Two teams of the forest department -- one at Sarankhola and another at Chandpai -- have been monitoring vessel operation, he said.

Though two days passed since the incident, the authorities were yet to start an operation to salvage the sunken vessel. They couldn't even say when the operation would begin.

“We don't have the capacity to conduct such an operation. We have informed other government agencies and are waiting for their response,” said Saidul.

Meanwhile, the forest department filed a case against the vessel owner and five others, claiming Tk 5 crore in compensation.

The accused are vessel owner Manira Kabir, Samata Shipping traders' owner Md Azizur Rahman, the company's manager Zamal Hossain, and vessel staffs Sirajul Hossain Molla, Ismail Farazi and Saidul Islam.

Sultan Mahmud, forester of Chandpai range, filed the lawsuit with Sarankhola Police Station.

Wishing anonymity, a member of the probe committee formed by Bagerhat district administration said primary investigation indicated that Seahorse-1 sank as it hit a sunken vessel, MV Shahi Doot.

“Our primary investigation shows the hull of the vessel cracked, as it collided with Shahi Doot,” said the committee member.

The forest department requested the Department of Environment to check whether the sinking of the coal-laden vessel has impacted the water quality of the river.

In December 2014, an oil tanker sank in the river, spilling a huge quantity of oil that tainted the water. Oil was seen on barks of trees and on soil for months.

IMPACT ON FOREST

Prof Abdullah Harun Chowhdhury of Khulna University said the coal in the sunken vessel would affect the biodiversity in the surrounding forest areas.

Since coal contains heavy metals such as arsenic, lead, mercury and nickel, these would mix with the river water and pollute the spawning ground of shrimp, crab, fish and dolphin in and around the scene of the accident, he said.

These heavy metals may also contaminate the food chain.

Moreover, soil fertility would decrease as the forest floor in the area would absorb these heavy metals during high tides.

Some impacts may last long, as natural degradation of heavy metal is very slow, added Abdullah.