Contamination from Iranian tanker spill could get much worse, China says

Bunker fuel may now be leaking from the Iranian oil tanker that sank in the East China Sea last Sunday, Beijing said, underlining fears for contamination from the world’s worst oil ship disaster in decades.

In a statement issued late on Thursday, China’s State Oceanic Administration (SOA) said several previously unreported slicks had been spotted by planes, vessels and satellites near the disaster site. One of them, seen 2½km (1½ miles) east of the wreck site about 6am on Thursday, might indicate leakage of extremely toxic bunker fuel, the heavy oil used in ship engines.

China monitoring four oil slicks from sunken Iranian tanker

It remains unclear how much bunker fuel was left aboard the tanker, the Sanchi, when it sank. Experts estimated it might have been carrying about 1,000 tonnes (8,450 barrels) at the time it collided with the CF Crystal grain freighter.

Bunker fuel is noxious to marine organisms and difficult to remove from the sea once spilled, unlike the condensate fuel – an extremely light form of oil – that was being shipped by the Sanchi at the time of the collision.

Seafood supply may be hit as Sanchi oil spill spreads in East China Sea

The Sanchi was carrying 136,000 tonnes of condensate before the accident, most of which evaporated after the stricken shipped burned for days.

The SOA said it would continue carrying out monitoring and environmental impact assessment works.

Three slicks covering a combined area of 20.7 square kilometres (eight square miles) were spotted by satellite, with the largest in size 17.4 square kilometres, the administration said.

Three possible outcomes from East China Sea oil spill, according to Chinese scientists

That combined area was 80.3 square kilometres smaller than the total reported a day earlier, but water samples taken at four of the 22 spill sites detected so far were found to exceed petroleum substance standards.