Since the entry of oil as a major energy source into human production, oil spills have occurred during the transportation process every year, and oil pollution incidents are not uncommon. Especially for shipping, according to statistics, the world's oil inflows into the sea each year due to shipwrecks amounted to 500,000 tons.
The effect of oil spills at sea is different mainly based on the distance from the coastline. For example, when the Atlantic Empress oil tanker sank following a collision in 1979 it spilled 280,000 tonnes of oil – the largest ever release from a tanker. However, the oil did not reach the coast, which lessened the damage. In contrast, the 1989 Exxon Valdez spill in Alaska was smaller but devastated 1,300 miles of coastline in the Prince William Sound, killing much of the local wildlife. Iranian tanker disaster and oil spill in East China Sea is an event of great disaster more than a hundred nautical miles from the coastline, the serious consequences of which are still to be estimated.
When the Iranian oil tanker Sanchi collided with a cargo ship, caught fire and sank in the East China Sea In mid-January 2018, an entirely new kind of maritime disaster was born. Nearly two weeks later, basic questions remain unanswered about the size of the spill, its chemical makeup and where it could end up. Without that crucial information, researchers are struggling to predict the short- and long-term ecological consequences of the incident.
At 19:50 on January 6, 2018, the Panamanian tanker "SANCHI" loaded with gas condensate and the Chinese Hong Kong-owned bulk carrier "CF CRYSTAL" collided about 160 nautical miles east of the Yangtze River estuary. The accident caused the "SANCHI" fire in the whole ship. Three crew members were killed and 29 crew members lost contact. The ship exploded on January 14 and then sank to the bottom of the sea. The final shipwreck position is 28 degrees 22 minutes north latitude and 125 degrees 55 minutes east longitude.
Until January 22, the "SANCHI" shipwreck caused a total of 332 square kilometers of water pollution. And the working vessel found about 58 square kilometers of oil pollution belt in the shipwreck area. On-site monitoring of the concentration of petroleum-like substances in individual waters reached 126μg / L, which is the poor quality of the four types of sea water. It is reported that the gas condensate carried by the shipwreck is similar to gasoline and has a very high volatility. It will be emitted quickly after entering the water, and it will easily explode in the air. This type of gas condensate contains toxic substances such as hydrogen sulfide and mercaptan, which will cause serious pollution to the atmosphere after volatilization, and will produce toxic fumes such as nitrogen oxides and sulfur oxides after combustion. This kind of toxic smoke can be absorbed by the human body through inhalation, skin invasion and other ways, resulting in human poisoning.
It is estimated that the gas condensate leakage caused by the collision incident will have a serious impact on the marine ecology of the East China Sea. There are many kinds of aquatic organisms in the East China Sea, rich in resources and high in specificity. After the accident, the living environment of some marine life is threatened. The location of the East China Sea oil spill was located in the Yangtze River estuary area of China and is an important fishery distribution area in China. Some experts estimate that fishing may be prohibited for a long time within a few hundred kilometers of the accident area after the incident. In addition, the subsequent cleaning work will also consume a lot of manpower and material resources, which may cause huge economic losses.
There are also different voices about the handling of events. Experts say the closure of fisheries is one of the first steps authorities take after major oil spills. But according to China's state-run media, Xinhua, the government's move to keep fishing vessels away came two days after Sanchi sank - that was 10 days after the collision. There are still several fishing boats continuing to catch the fishing operations within a few days. Besides, When the blaze was 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”. And the other thing is 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”.
Regarding the cause of the accident, the Chinese and Chinese Hong Kong investigators thought that the "SANCHI" as the roadside vessel did not take the way to make a direct cause of the accident. Iran and Panama investigators believe that the action of the "long peak crystal" wheel to adjust the ship to the planned route 15 minutes before the collision is the direct cause of the accident, but the results are still under investigation.
 What's the impact of the East China Sea oil spill? | China Dialogue https://www.chinadialogue.net/article/show/single/en/10346-What-s-the-impact-of-the-East-China-Sea-oil-spill-
 Unique oil spill in East China Sea frustrates scientists
 1·6东海船只碰撞事故（1·6 East Sea vessel collision accident）
 东海撞船事故原因与责任分析（Analysis on the causes and responsibilities of ship collision in the East China Sea）
 桑吉号东海溢油：史上首次大规模轻油泄漏，日本南韩恐难逃污染（SANCHI tanker oil spill in the East China Sea: the first large-scale light oil spill in history, Japan and South Korea may not escape pollution）
 “桑吉”轮漏油明显扩散，油污带已达58平方公里（The oil spill of the SANCHI wheel has spread obviously, and the oil spill zone has reached 58 square kilometers）
 “桑吉”轮倾覆溢油对东海海洋环境 危害究竟有多大？（How much harm does the SANCHI wheel overturn oil spill on the marine environment in the East China Sea?）
 一文读懂东海撞船漏油事故：海洋生态或受严重影响 附最新搜救消息！（Understand the East China Sea collision oil spill: ocean ecology may be seriously affected. With the latest search and rescue news!）
 'Fishing continued' after East China sea oil spill https://www.bbc.com/news/science-environment-43142538
 East China Sea oil tanker disaster: what it means for the environment | World news | The Guardian