NOC: Sanchi Pollution May Reach Japan’s Ryukyu Islands

Water polluted by the Iranian-flagged Sanchi oil tanker may reach coral reefs in Japan’s Ryukyu Island chain, the latest ocean model simulation shows.

The latest predictions, unveiled by scientists from the National Oceanography Centre (NOC) and the University of Southampton, were made following information about the suspected arrival of some of the oil from the Sanchi oil tanker at Amami-Oshima, an island at the edge of the East China Sea.

Previously, simulations were based on the Sanchi oil tanker’s final resting site, and found the proximity of the oil to the major Kuroshio Current significantly increased the potential area affected by the spill, including the Greater Tokyo Area hundreds of miles away. Earlier predictions also suggested that the island of Amami-Oshima would be threatened by oil contamination some 20-30 days after the Sanchi sank, however, oil contamination reached the island after only 20 days.

While these new simulations focus only on the fraction of the pollution that has reached Amami-Oshima, they find that refining the pathway of the spill actually extends the potential region of impacts.

Previously only regions to the north and east of the Sanchi wreck were predicted to be affected, but these latest simulations point towards impacts on the Ryukyu Island chain to the south and west, with a small risk of contamination reaching the vicinity of Taiwan.

“Since these new results are based on only a small part of the region that our previous model projections predicted would be affected, I am concerned that the spread of pollution may actually be more extensive and complex than we previously thought,” Stephen Kelly, the University of Southampton PhD student who ran the model simulations, said.

“By including this one new spill location, we’ve found an additional region to be potentially at risk, but information on the fate of the spill has been limited and we might be missing further areas. So a large-scale monitoring effort is critical if the impact of the spill is to be properly understood,” NOC scientist, Dr Andrew Yool, who collaborated in this study, added.

The ill-fated tanker Sanchi sank in the East China Sea on January 14. The vessel capsized some 530 km from Shanghai and 310 km from Naha, Japan, following a collision and a number of explosion aboard the ship. The vessel lies at a depth of around 115 meters.

At the time of the incident, Sanchi was carrying 136,000 metric tons of ultra-light, highly flammable condensate.