Coast Guard determines Huntington Beach oil sheen most likely from natural seepage

After concerns that a 2.5-mile ocean water oil sheen in Huntington Beach last week was caused by malfunction or error from ships or nearby oil platforms, the U.S. Coast Guard says it was more likely from natural causes.

The sheen was spotted March 7 in the evening, and the Coast Guard began investigating and cleanup the following day. By day's end March 8, the agency reported that they cleaned up as much as possible, saying about 85% of the sheen, roughly 85 gallons of product had been recovered.

A recovery team responded to the shoreline for testing and cleanup as tar balls were in high concentration in the Huntington Dog Beach area. Three oiled birds were recovered, a cormorant, loon, and grebe.

A March 11 Coast Guard written update said that Unified Command has finished investigating the offshore oil sheen and that collected samples were found to be weathered crude oil and not a refined product like gasoline or diesel.

"The preliminary laboratory results indicate that the oil samples analyzed from this incident are more characteristic of freshly produced oil than heavily weathered oil, which is associated with typical natural seeps," Coast Guard District Eleven wrote.

The report further stated that the samples were not consistent with samples taken from oil platforms in the area.

"While it is believed this was a one-time event, samples will be taken for additional analysis if another release is observed," Coast Guard District Eleven wrote.