Tar balls that washed ashorefrom San Francisco to Monterey this week came to the Peninsula from normal ocean-floor movement in Southern California and not from the Cosco Busan oil spill, officials involved in the investigation said.
Instead, they said, the dime- to Frisbee-size balls of hard, old oil came from Mother Nature.
U.S. Coast Guard, California Department of Fish and Game and U.S. Geological Services officials confirmed after testing samples that the tar balls had no association with the 54,000 gallon spill from the tanker into San Francisco Bay on Nov. 7.
The clumps that washed ashore at local beaches this week likely came from “burps” in the ocean floor off the coast of Southern California, according to the Coast Guard, officials from Fish and Game and Tom Lorenson, a U.S. Geological Survey research geologist in Menlo Park.
Recent storms changed the coastal water current, drifting the oil north an abnormal distance up the Pacific Coast, Lorenson said.
Tar balls regularly wash ashore on the Peninsula during wintertime and after winter storms, he said.
The amount of tar that landed on beaches was “significantly more” than usual and reached an unusually northern point, with a couple balls found at Ocean Beach, Fish and Game spokeswoman Carol Singleton said.
The recent storms likely played a role in the amount and distance the tar traveled, officials said.
San Mateo County beaches such as Sharp Park, Esplanade, Rockaway and Linda Mar were cleaned up by late morning by 12 person teams, Singleton said.
The three remaining beaches that need work today are Poplar, Pescadero and Seaside, which should be cleaned by this afternoon to wrap up Peninsula cleanup efforts, Coast Guard Petty Officer Kevin Neff said.
Reports of long oil sheens off the Peninsula coast proved to be false, said Fish and Game Lt. Brian Arnold. Three small Coast Guard boatsand a helicopter responded off Linda Mar beach in Pacifica and again off San Gregoria Beach south of Half Moon Bay and found no liquid oil. The reports were likely large swarms of the jellyfish Velella velella, he said.