Update Friday, 3 p.m.:
Lab tests conducted by the state Department of Fish and Wildlife Office of Spill Prevention and Response have concluded that Coast Guard vessels in the Oakland Estuary were not the cause of what officials are calling a "mystery sheen" of diesel fuel that appeared near Alameda Marina late Tuesday night.
"The amount of diesel that was spilled most likely didn’t come from one boat at the marina," OSPR spokesman Eric Laughlin said. "We are continuing the investigation to determine the source, but we can rule out those two Coast Guard cutters based on the samples we took."
Laughlin said the precise size of the spill that prompted a voluntary evacuation from the marina Tuesday night is difficult to determine. For one, the fuel evaporated quickly in this week's sunny weather, he said.
The Oiled Wildlife Care Network was mobilized for the spill, but no confirmed reports of affected animals have surfaced, Laughlin said. He estimated the cleanup would be finished Friday.
Deb Self, executive director of San Francisco Baykeeper, said that since the Cosco Busan disaster in 2007, ships or marine terminals responsible for a spill are required to coordinate a cleanup within two hours. But there is no such requirement when the source of a spill is unknown.
"This most recent mystery spill highlights the need for better communication from responding state agencies, and the Coast Guard, when the party responsible for the spill is unknown," she said. "It could be that the state had adequate resources out and the agencies were coordinated, but it’s hard for me to know because we didn’t have access to the information on a real-time basis."
She said a communication breakdown between the Coast Guard, state agencies, local responders and non-governmental organizations was one of the main problems of the 2007 incident that spilled 53,000 gallons of heavy fuel oil into the San Francisco Bay.
Update Wednesday, 2:20 p.m.:
Two Coast Guard cutters have not been eliminated as the source of an overnight oil spill in the Oakland Estuary, Coast Guard Ensign Jake Urrutia said, but he added that the vessels are not the only potential cause of the leak.
A barge alongside one of the cutters this morning was transferring fuel, he said, and deploying a chemical boom around one of the ships was routine.
"Any time a Coast Guard vessel does fuel transfers, they'll put a boom out," Urrutia said. "It's a precautionary measure in case something happens."
Original post (Wednesday, Feb. 11):
The Coast Guard and other agencies are investigating an oil spill in the Oakland Estuary overnight that prompted a voluntary evacuation of the Alameda Marina.
There is a bright yellow boom, or floating containment system, surrounding a Coast Guard vessel near its base on an island in the estuary.
Petty Officer 2nd Class Dave Irvin said the Coast Guard began a response at first light, some seven hours after people at the marina noticed a strong smell of fuel and an oil slick on the water.
Irvin said the Coast Guard and the California Department of Fish and Wildlife are taking water samples to determine what was spilled and nail down the source. He said the primary suspect is one of two Coast Guard cutters in the estuary.
"People in boats were contacted by marina security and told that it was our opinion that it would be better if they didn’t stay in the marina," Harbormaster Brock de Lappe said, "but we didn’t force any kind of an evacuation."
DeLappe added that calling the incident an oil spill might be misleading.
"Well, the Coast Guard says it is an oil spill," he said. "It is petroleum. It’s not heavy black crude oil -- it’s a fuel. It’s not gooey, black tarball oil."
Hayward resident Mark Foley was on his boat in the marina last night when he noticed "just an extremely intense smell of fuel," he said.
"I split, I got out of here," Foley said. "The smell of fuel was too intense, you could see it in the water. It was just really thick."
Foley returned to the Marina early this morning to see the Coast Guard deploying the boom around one of the cutters.
"The smell is still intense and you can still see the rainbow sheen on the water from all the fuel," Foley said. "There’s no birds out here. Normally there’s birds everywhere."
Coast Guard officials were investigating a separate oil spill near Shell's Martinez refinery last night when they got word of the Alameda spill.