Oil Spill Spreads in East China Sea, Could be Largest in Decades

China is racing to prevent an environmental disaster as four separate oil slicks have been spotted in the East China Sea following the sinking of an Iranian tanker on Sunday.

The slicks, which cover a combined total area of 100 square kilometers, each range in size from 5.5 to 48 square kilometers and are expanding and spreading northward due to wind and sea currents, according to China's State Oceanic Administration (SOA). Meanwhile, water samples taken from 19 spill sites revealed that five areas had petroleum levels that exceeded standards.

Some experts say the spill could shape up to be the worst since the 1989 Exxon Valdez oil spill in Alaska.

The spill was caused after the Sanchi, a Panama-registered Iranian oil tanker, collided with a Hong Kong-registered bulk freighter on the evening of January 6 roughly 160 nautical miles (296 kilometers) east of the Yangtze River estuary in Shanghai. The tanker was carrying 136,000 tonnes of light crude oil at the time of the collision, the cause of which remains unknown.

Three bodies were recovered from the Sanchi, while another 29 missing crew members were presumed dead. The Sanchi's 32-member crew included 30 Iranians and two Bangladeshis.

The ship burned prior to its sinking.

On January 14, eight days after the collision, the vessel suddenly ignited before completely capsizing, bringing its condensate and ship fuel to the sea floor (likely with the fuel tanks intact). The tanker had been burning off the coast of China for over a week and spilling fuel in the surrounding waters. Some of the oil evaporated in the fire, and flames were seen burning on the sea's surface until Monday, though it's unclear exactly how much oil spilled into the water. Strong winds had pushed the ship into Japanese waters prior to its sinking.

On Wednesday, China's Ministry of Transportation said it discovered the vessel, located 115 meters underwater. The clean-up is now currently underway, with Chinese, Japanese and Korean vessels being dispatched to monitor the drift,  assess the ecological damage and stop the flow of condensate, a colorless hydrocarbon liquid typically used for making petrochemicals such as jet fuel. Toxic and highly flammable, condensate is only partially soluble in water and can devastate marine life.

"The marine ecological environment has been affected," said the SOA. Some experts warn that the damage is "very serious" and that the leaked oil must be dealt with adequately and urgently to avoid jeopardizing the surrounding ecosystem, according to China Daily.

Experts told Sixth Tone last week that an explosion and sinking would be the "worst-case scenario," and that oil spilled into the seawater would likely affect the marine ecosystem. The Zhoushan fishing grounds in the East China Sea, where the collision occurred, supply roughly 40 percent of the country's fish harvests. According to Greenpeace, the area is also right in the migratory path of the humpback whale.

Meanwhile, some experts have criticized the handling of the incident, with some telling Caixin that the ship should have been 'bombed' to burn the fuel out, instead of letting it seep into the surrounding waters and ocean floor.

[Images via Shine, CGTN, China Daily]

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