Coast Guard probes fuel spill in San Francisco Bay

SAN FRANCISCO (Reuters) - A two-mile long slick of bunker fuel stretched across part of San Francisco Bay on Friday after a refueling mishap between a tanker and a barge alongside, the U.S. Coast Guard said.

The slick has not reached land and is in a narrow band because there is little wind and much of it may burn off amid warm weather, giving clean-up crews the upper-hand in containing it, Coast Guard Captain Paul Gugg told reporters at a press conference.

"The weather is very cooperative," Gugg said. "We're all over it."

Gugg said the scope of the contamination does not compare to the massive spill in 2007 of fuel oil from another tanker in the San Francisco Bay that spread across its shores and killed thousand of birds.

But Gugg said it remained unclear how much bunker fuel had spilled into the bay.

A floating boom surrounds the Dubai Star tanker, the source of the spill has been sealed and other tanker traffic and operations in the bay were unaffected, Gugg said.

An investigation in under way to determine if the spill was caused by human error or mechanical failure, he added.

Pioneer Ship Management Services LLC, technical managers of the Dubai Star, said in a statement its spill response contractor, O'Briens Response Management, also is mobilizing clean-up resources to contain and recover the spilled fuel.

The spill comes eight days before the two-year anniversary of the vessel Cosco Busan striking the Bay Bridge in dense fog, ripping open its hull and spilling more than 53,000 gallons (220,000 liters) of fuel oil that fouled much of the shoreline along the well-known California waterway.

Jackie Dragon, program director for marine sanctuaries at San Francisco-based Pacific Environment, said the bay's tidal waters spread oil products very quickly and she hoped the authorities had improved their response time in the past two years.

"Today is an opportunity to see if efforts to improve the coordination between state agencies and local authorities have provided the on-the-water response to clean up oil before serious harm is done," Dragon said in a statement.

State wildlife officials said at a news conference there had not yet been any impact on birds.

Pacific Environment said the Busan spill killed at least 2,519 birds and left oil on 200 miles of coastline.

(Reporting by Jim Christie and Braden Reddall in San Francisco; Editing by Marguerita Choy)