(Corrects Cosco Busan's ownership in paragraph 8 to Greek firm Synergy Maritime from China COSCO Holdings) By Amanda Beck SAN FRANCISCO, Nov 7 (Reuters) - A container ship bound for China struck a fog-shrouded tower of San Francisco's Bay Bridge on Wednesday morning, causing a fuel spill and forcing the closure of several San Francisco beaches, officials said. People near the spill reported suffering headaches and nausea as they breathed air containing vaporized oil, but public health officials said the fumes were not likely to have long-term health effects. Four picturesque beaches on both sides of the landmark Golden Gate Bridge -- Baker, Fort Point, China, and Crissy Field -- were closed, according to the U.S. Coast Guard. "There is a sheen in the water. It is bunker fuel," said Coast Guard Petty Officer Kevin Neff about oil used to propel the ship. As of Wednesday evening, investigators were still trying to determine the cause of the accident and how much fuel had spilled into the bay. Early reports had described the leak as 3-feet (1-metre) wide. Wil Bruhns, supervising engineer of San Francisco Bay Regional Water Quality Control Board, said the oil could pose a threat to wildlife like seals, fish and birds. "Bunker fuel oil tends to be rather heavy, and it doesn't float as well as other oil. It's harder to contain," Bruhns said. The Cosco Busan, owned by Greek firm Synergy Maritime, left the Port of Oakland at 6:31 a.m. on Wednesday and about two hours later hit a fender around a support tower on an especially foggy morning. Transportation officials said part of the fender would need to be replaced, but said the incident did not damage the bridge and traffic continued to flow. The Bay Bridge is a vital transportation link between San Francisco, Oakland and Berkeley. Ships heading into the Pacific Ocean travel under the Bay Bridge and then the Golden Gate Bridge before reaching the high seas. (Additional reporting by Adam Tanner)
