The fire that was burning on the water surface at the site of the sunken Iranian tanker Sanchi has gone out, China’s Oceanic Administration said in an update on Monday.
However, Chinese authorities have discovered various oil slicks at the site which have been extending northward from the position of the wreck.
There is an 18.5 km long, 1.85-7.4 km wide condensate leak zone around the area, the agency said.
Monitoring activities at the site continue and the agency said it was collecting water samples from the site for inspection purposes.
Nevertheless, the exact extent of the pollution and environmental impact of the accident is yet to be determined.
“There is also the possibility of a fuel oil spill. 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 on January 6.
“As the fuel oil cools, it will become more viscous which will help to slow or even prevent leaks. In this scenario, it is possible that we will see chronic low volume leakage over a period of time at the seabed. The impact would remain relatively local,” Paul Johnston from Greenpeace International’s Science Unit in the University of Exeter, UK, said.
What is more, according to Greenpeace experts from East Asia and Japan, the explosion and sinking of the Sanchi occurred in an important spawning ground for many commercial species such as the bluefin leatherjacket and the swordtip squid. The area is also on the migratory pathway of many marine mammals, such as humpback whale, right whale and gray whale.
The Sanchi was carrying 136,000 tons of condensate oil, which is very volatile, meaning that much of the substance will have been consumed in the fire and that most of the spilled condensate will evaporate into the air.
A proportion of condensate spilled will dissolve into the water, and this will be locally toxic until it dilutes enough to be broken down by natural processes, probably quite quickly, Greenpece explained.
Any condensate that does spill may produce a surface sheen, though that may be hard to see or detect in current weather conditions, which will evaporate, dissolve or disperse quite quickly.
Based on the estimates of China’s Ministry of Transport less than 1 percent would remain on the sea surface 5 hours after the collision.
“Now that the tanker has sunk, it is important that operations now shift from salvage and recovery, to assessment of the impacts of the potential condensate spill. An assessment of how much condensate has been spilled must be conducted as soon as possible and appropriate containment and clean-up measures adopted,” Greenpeace stressed.
The Sanchi sank on January 14, 530 km from Shanghai and 310 km from Naha, Japan.
The hope of finding any survivors of Sanchi’s 32 crew members has diminished, according to Iran’s Ports and Maritime Organization (PMO).
Three bodies have been recovered from the vessel and are yet to be identified.
World Maritime News Staff