Body of sailor from Sanchi found and 31 others missing amid fears of environmental catastrophe after crash with container ship

Bad weather has hindered efforts to contain a tanker fire and oil spill off the coast of China, as environmental groups warned of a potential catastrophe.

The body of one sailor had been found and 31 others were missing after an Iranian-owned tanker collided with a container ship about 160 nautical miles east of Shanghai on Saturday evening. The Sanchi was carrying 136,000 tonnes of light crude oil or about 1m barrels.

However, strong winds, rain and waves up to four metres high were impeding efforts to contain the fire, locate the missing crew members and limit environmental damage, China’s transport ministry said. Rescuers onboard 13 vessels were searching an area of 900 sq nautical miles (3,090 sq km).

The tanker “is in danger of explosion and sinking, and the toxic gas … is very harmful to rescue workers on the scene”, officials said.

The Sanchi was loaded with condensate, a form of oil that only remains in liquid form under specific conditions and is more volatile compared with crude oil.

Nearly three days after the collision, as fires continue to burn, environmental concerns are mounting.

“We are extremely concerned about the potential environmental impact of the collision and fire,” said Rashid Kang, a campaigner at Greenpeace. “Condensate oil contains much higher proportions of soluble and toxic chemicals. We are not expecting to see the kind of devastating thick oil slick associated with crude oil spills, but are worried about the toxic pollution that could be caused from leaks of condensate.”

Another concern is the impact on local wildlife. “The environmental impact of this disaster could be catastrophic,” said Dave Tickner, a freshwater adviser at the World Wide Fund for Nature. “The consequences will be far more severe if it affects a wide area of ocean or the Yangtze estuary, which is hugely important for wildlife, including significant numbers of migratory birds and a range of fish species. We need urgent action to clean up the spill and ensure the environmental consequences are limited.”

Chinese authorities were investigating the cause of the crash. The Sanchi, a Panamanian-flagged vessel owned by the National Iranian Tanker Company, was sailing to South Korea from Iran when it collided with a Hong Kong-flagged cargo ship, the CF Crystal, carrying 64,000 tonnes of grain. The Crystal’s 21 Chinese crew were rescued.