East China Sea oil tanker disaster: what it means for the environment

Ship was carrying 136,000 tons of oil that now threatens to pollute some of China’s most important fishing waters
Benjamin Haas The Guardian 16 Jan 18;

The Iranian oil tanker Sanchi sank off the coast of Shanghai on Sunday, after a week of burning and sending plumes of smoke hundreds of metres into the air. Only three bodies of the 32 sailors were recovered. The ship was carrying 136,000 tons, or about 1 million barrels, of oil, that now threatens to pollute some of China’s most important fishing waters.

What was Sanchi transporting?

The oil tanker was carrying condensate oil, which differs considerably from the thick black oil slicks typically associated with a spill. Instead, the colourless oil is a liquid only under certain conditions and is partially soluble in water, making it much harder to separate and detect.

How much oil leaked?

Currently, it is impossible to gauge exactly how much condensate ended up in the water. Some of it burned off and some probably evaporated, but any oil still onboard when the ship sank will slowly leak out over time and be difficult to contain.

What will the impact be on the local environment?
The condensate that leaked into the water could potentially wreak havoc on local fish spawning grounds and the Sanchi sank in the migratory path of the humpback whale, according to Greenpeace.

While there will not be black beaches covered in oil, condensate is toxic when inhaled and on the skin and is described as “toxic to aquatic life with long lasting effects”.

Another concern is the fuel that was powering the Sanchi. The day after it sank, China’s State Oceanic Administration reported two oil slicks, one nearly 15km long and another about 18km long, although it is unclear if these are from the cargo or the fuel tanks.

“Given that the fuel tanks in these sorts of vessels are located close to the engine room, it is likely that the fuel tanks have remained intact since the initial collision,” said Paul Johnston, a research fellow at the University of Exeter.

“It is possible that we will see chronic low volume leakage over a period of time at the seabed. ... Impact would remain relatively local.”

What could China have done differently?
There were two competing goals in dealing with the tanker: putting out the fire in an effort to rescue the crew, or allowing as much oil as possible to burn off to limit polluting the waters. In the end, there was a mixture of both.

The National Iranian Tanker Company, the firm that operated the ship, had two ships nearby and a spokesman for the company wondered why Chinese fire fighting boats were using water to douse the flames when foam would be more effective.

While the blaze was still burning the Iranian Merchant Mariners Syndicate, an industry group, voiced frustration at the lack of progress in putting out the fire, and said it was “clear that the Chinese are not cooperating enough”.

Other criticised Chinese efforts to subdue the fire, and suggested a plan that would have assumed the entire crew had no hope of rescue.

Yu Zhirong, a former deputy of the East China Sea unit of China Marine Surveillance, told business magazine Caixin the Sanchi should have been bombed or torpedoed, causing an explosion that would burn up the remaining oil and limit the amount the seeped into the ocean.

Allowing the ship to sink was described as the “worst-case scenario”.

What happens now?

China has announced it will conduct an investigation into the incident, although there is no sense when a report will emerge and how detailed it will be. Greenpeace has called on China to assess how much oil spilled into the ocean and take “appropriate containment and clean up measures”.



Massive oil spill spreads in East China Sea, could be world's largest in decades
Andrew Freedmann Mashable Yahoo News 17 Jan 18;

What could be the largest oil spill since 1989's Exxon Valdez is unfolding in the East China Sea after a deadly and fiery collision between two vessels caused a tanker to sink. All 32 crew members are thought to have died aboard the Iranian vessel "Sanchi," which was carrying about 1 million barrels of condensate.

According to Bloomberg News, the ship was transporting hydrocarbon liquid that's a key ingredient for making petrochemicals, including jet fuel. It was headed to the port of Daesan, South Korea when it struck the transport ship "CF Crystal" off China's eastern coast.

The tanker and its associated oil slick had been on fire for days after the collision. While the fire likely killed all aboard the ship, it was seen by environmental experts as a way to minimize the broader impacts of the spill, since the flames burned off the lightweight condensate on the ocean surface.

However, the fire is now out, and the ship has sunk, raising the possibility that the harmful cargo is going directly into the sea.

The cargo is different than the crude oil spilled by the Exxon Valdez in 1989, but if all the condensate were to leak into the ocean, it would rank as the biggest spill in decades.

Much remains unknown about the fate of the cargo, and therefore similar can be said about what the environmental impacts will be. Reports in recent days are not encouraging, since there is word of a rapidly spreading oil slick on the surface of the ocean. Citing Chinese authorities, Bloomberg reported that the spill expanded from 3.9 square miles to 52 square miles between Sunday and Monday local time.

An oil spill in the heavily trafficked East China Sea could have significant environmental repercussions. Humpback whales travel through that area, and heavily fished species such as mackerel and bluefin also spend time in that area.

“It is virtually certain that much of the condensate went into the sea in solution, and that toxic underwater hydrocarbon plume will injure marine life exposed to it,” Richard Steiner, an oil spill specialist based in Alaska, told Bloomberg. “Even the burned fraction will leave a toxic residue on the water.”

Ma Jun, a Chinese environmentalist, was quoted by CNN as saying the spill took place in one of the most productive fishing areas in the country, known as the Zhoushan fishing ground.

"We still need to keep an eye on how these contaminants might be carried by the ocean flow to have the impact on the fishing ground," Jun told CNN.

According to Greenpeace International, it's not clear how large this environmental disaster will be, since the amount of condensate that leaked into the water is unknown.

"A major concern is that, now that the tanker has sunk, any condensate which did not yet burn off could continue to leak underwater, disperse and break down quite quickly, significantly complicating clean up operations," the environmental advocacy organization stated in a Jan. 15 fact sheet.


Sunken Iranian tanker could cause 'irreversible' environmental damage after leaving oil slick the size of Paris
Sunken ship thought to be leaking toxic engine fuel, raising concerns for fisheries and marine wildlife
Chris Baynes The Independent 19 Jan 18;

An Iranian oil tanker that sank in flames off the east coast of China is thought to be leaking heavy bunker fuel, raising fears of an environmental disaster.

Experts warned “irreversible” damage to marine wildlife was possible after the ship sank on Saturday, leaving behind an oil slick the size of Paris.

The Sanchi had drifted ablaze for eight days after a collision with a freighter in the East China Sea, one of the worst oil ship disasters in decades.

The tanker’s crew of 30 Iranians and two Bangladeshis are all believed to have died.

At the time of the crash, the Sanchi was carrying 136,000 tons – almost one million barrels – of condensate, an ultra-light, highly flammable crude oil.

The Chinese State Oceanic Administration (SOA) said five oil slicks with a collective area of 101sq km had been spotted on Wednesday, although they had shrunk to about a quarter of the size by the next day.

Authorities said bunker fuel, a heavy oil used in ship’s engines, was now also believed to have leaked from the vessel since it sank. The Sanchi is thought to have been carrying about 1,000 tons of bunker fuel, which is toxic to marine organisms and difficult to remove from the sea once spilled.

Experts said the scale of the environmental damage would not be clear until the volume of leaked fuel was known, but warned fisheries and marine life could be impacted for years to come.

Paul Johnson, research fellow at Greenpeace International’s Science Unit at the University of Exeter, said bunker fuel was “particularly dangerous to birds and other wildlife”, and could sometimes be fatal if encountered by whales, dolphins and porpoises.

He told The Independent: “The major impact is going to be living marine organisms that are exposed to the oil slick, which is quite a big one now. It’ll taint fish, it’ll kill fish. If cetaceans encounter it they could be at very severe risk of doing themselves some serious damage.”

Greenpeace said the ship sank in an important spawning ground for species including the hairtail, yellow croaker, chub mackerel and blue crab. The area is also on the migratory pathway of several marine mammals, such as the humpback whale, right whale and gray whale.

Babatunde Anifowose, a senior lecturer in petroleum and environmental technology at the University of Coventry, said the spill could potentially have “irreversible environmental impacts” depending on the “the state of aquatic resources prior to the oil spill”.

The mass death of fish was one worst-case scenario, Dr Anifowose said, although he stressed “this is just one of the numerous possibilities” and depended on the levels of oxygen in the waters.

“The quantity of oil spilled is key in operational response efforts and assessing the likely environmental impacts,” he added. “No two oil spill incidents can ever be the same. This oil spill case is therefore unique and would require specific assessment that depends on the baseline environmental conditions at the location.”

The SOA said it was monitoring the spill’s environment impact. Water samples taken at four of the total 22 spill sites detected so far were found to exceed petroleum substance standards.

Dr Johnson said: “There’s no such thing as a good oil spill. There’s a really strong need for monitoring activities to expand in scale so we’ve got a good picture of how the petroleum hydrocarbons are spreading in the environment, and there’s also a need for surveillance monitoring of the living marine resources there – the sorts of things people might be likely to eat.”

The Chinese transport ministry’s emergency response department said it plans to send a robot submarine, possibly followed by divers, to explore and plug holes in the ship. No timeline was given for the mission.

Depending on conditions, divers might also be able to pump oil from the vessel’s fuel tanks before they leak further and contaminate the seabed.

Authorities say the Sanchi is lying under 115m (377ft) of water in the East China Sea, about 530km (330 miles) south-east of Shanghai. Despite fears of environmental damage, the sinking is not thought likely to create oiled beaches such as those caused by the uncontrolled blowout on the Deepwater Horizon oil rig in the Gulf of Mexico in 2010.

The UK National Oceanography Centre, using a computer simulation model, predicted waters polluted by the sinking oil tanker could reach Japan within a month. However, it said the fate of the leaking oil was uncertain.

“It may contaminate beaches but I doubt it will be a thick slick,” said Dr Johnson.