Japan Oil Spill Downgraded; Shipping Proceeds

Fears of an environmental and economic disaster from an oil spill in Tokyo Bay receded somewhat on Thursday after the Japanese government sharply reduced the estimated size of the leakage and cleanup efforts made headway.

The government said on Thursday that only about 400,000 gallons of crude oil escaped from a Japanese-owned tanker that ran aground off Yokohama on Wednesday, just one-tenth the volume first reported.

Officials, relieved if somewhat embarrassed, explained that much of the oil they presumed had gushed into the water had actually flowed into another tank on the ship itself.

“It was really a miraculous occurrence,” Seiroku Kajiyama, the chief Cabinet secretary, said at a news conference.

Scores of boats continued efforts on Thursday to contain the oil, sop it up or disperse it with chemicals. The slick, which early Thursday morning had spanned the bay’s entire width, was driven toward the west side of the bay by winds, currents and cleanup efforts and seemed to be shrinking. It hugged the western shore near Kawasaki, an industrial area, and measured about 5.5 miles by 8 miles.

Cleanup was aided by the fact that the crude oil was relatively light - about half of it has evaporated, or is expected to. The slick is mainly very thin, not heavy and tar-like, which makes it easier to scoop up from the water’s surface, according to an official of the oil spill response office of the Petroleum Association of Japan.

However, the thinness also means the slick is spreading out over a wider area. Some of its lighter components can dissolve in water, posing a potential threat to small marine organisms, some experts said.

Officials at the two largest ports in Tokyo Bay reported on Thursday that shipping was proceeding more or less normally. A major economic concern had been that the spill would disrupt shipping in the busy waterway, which has six major ports serving Japan’s largest population, business and industrial center.

Dead or injured birds soaked with oil, a common casualty of such spills, have not been found so far, said Sadayoshi Tobai, a wetlands officer for the World Wide Fund for Nature. He said that there was concern about the little tern, a rare bird that is in its breeding season, and the common cormorant. The spill also threatens an important tidal flat, he said.

It is still unclear how the spill will affect fisheries in Tokyo Bay, where the catch is worth about $200 million a year. Most fishermen stayed home or helped with the cleanup on Thursday rather than fishing. Some complained that the chemicals used to help disperse the oil could be as harmful as the oil itself.