East China Sea oil slick triples in size along whale migration route

The spill from a sunken Iranian tanker off China’s east coast has more than trebled in size, just over a week after the ship sank in a ball of flames.

Authorities spotted three oil slicks with a total surface area of 332 square kilometres (128 square miles), compared to 101 sq km reported on Wednesday, the State Oceanic Administration said late Sunday.

China monitoring four oil slicks from sunken Iranian tanker

The Sanchi, which was carrying 136,000 tonnes of light crude oil from Iran, collided with Hong Kong-registered bulk freighter the CF Crystal in early January, setting off a desperate race by authorities to search for survivors and stave off an environmental catastrophe.

The bodies of only three of the ship’s 30 Iranian and two Bangladeshi crew members have been found. 

Three coastguard vessels were on the scene on Sunday night assessing the spill, the oceanic administration said.

The type of condensate oil carried by the Sanchi does not form a traditional surface slick when spilled, but is nonetheless highly toxic to marine life and much harder to separate from water. The cargo amounted to nearly one million barrels of oil.

The administration said on Sunday that an oil slick 5.4km long and 1.4km wide was seen about 5km northwest of the tanker’s location.

A day earlier it said a slick about 4km long and 400 metres wide was sighted about 5km southeast of the tanker’s location.

High alert for huge oil slick in East China Sea, but how bad will it be?

Satellite data showed three oil slicks totalling about 332 sq km within the monitored area. The largest measured about 328 sq km.

The area where the ship went down is an important spawning ground for species like the swordtip squid and wintering ground for species like the yellow croaker fish and blue crab, among many others, according to Greenpeace. 

It is also on the migratory pathway of numerous marine mammals, such as humpback and grey whales.