DHAKA, Bangladesh -- Authorities in Bangladesh were urgently assessing environmental damage in one of the world's largest mangrove forests on Friday after an oil tanker sank, threatening wildlife in the UNESCO World Heritage site, officials and local media said.
The oil tanker carrying more than 92,500 gallons of bunker oil sank Tuesday on a major river flowing through the Sundarbans after being hit by a cargo vessel.
Officials said Friday the slick had spread over up to 45 miles of the Shela river, a major sanctuary for aquatic animals in the Sundarbans. At least 20 canals connected with the Shela as well as another major river, Pashur, have also been affected.
The oil spill is threatening several types of animals including rare Irrawaddy dolphins, a senior official of the Bangladesh Forest Department said.
"The risk of damage to the biodiversity is high but we have yet to confirm any deaths of major animals including dolphins and crocodiles," said Tapan Kumer Dey, chief conservator of forest wildlife.
The sunken oil tanker was salvaged Thursday, more than 30 hours after it sank, and two of its six containers were badly damaged, said M. Giasuddin, an official of the company that owns the vessel.
He said it was not clear whether all of the oil had spilled into the water. Some news reports said more than 52,800 gallons of oil had contaminated waters in the Sundarbans.
"Several teams are desperately trying to determine the immediate impact. We are closely monitoring the situation as this is a major disaster," Dey said.
"We have spotted dolphins coming out of the water for air and going down again in some places," he said. "Crocodiles' movement in the affected areas has been less after the disaster and we are trying to determine actually what happened to them."
Dhaka's Daily Star newspaper said oil has covered grasses and other plants on the banks of the rivers. It quoted a local resident as saying that he spotted two dead animals, a monitor lizard and an otter.