The Monterey harbormaster reported the spill at about 8:30 p.m. About 10 gallons of diesel fuel was released from a bilge pump on a 38-foot fishing vessel and the fuel appeared to be contained within four boat slips, the Coast Guard reported.
A Coast Guard crewmember boarded the vessel and secured the bilge pump and the harbormaster notified the boat's owner, who responded with boom and pads.
Coast Guard pollution investigators went to the area Monday morning and reported seeing a light sheen. The sheen was expected to naturally dissipate and containment booms remained in place Monday afternoon.
Investigators determined the cause of the spill was a broken fuel line that discharged fuel into the vessel's bilge and activated the bilge pump, according to the Coast Guard. The boat's owner has since repaired the fuel line.