A cleanup effort is under way in the San Francisco Bay near Treasure Island where an oil sheen was spotted in the water, according to the U.S. Coast Guard.
Someone walking along the shore noticed the oil and called authorities shortly before noon.
The sheen is right next to the U.S.S. Wenonah, a decommissioned naval tug moored to the east side of the island. The boat appears to be sitting low in the water and the oil sheen and debris could be seen in the water nearby.
Coast Guard Lt. jg Jeremy Pichette said shortly before 3:30 p.m. that the sheen had spread as far as the Berkeley Marina and that spill investigators had been sent there as well.
The Coast Guard provided the initial cleanup materials, including absorbent boom, and dispatched an 87-foot patrol boat, a 41-foot utility boat and a helicopter.
A 200-foot "safety zone" has been set up around the tug boat.
The Coast Guard has contracted the private company Parker Diving and Salvage to perform the cleanup.