An oil sheen that appeared off the coast of Huntington Beach late last week was caused by a natural seepage from the ocean floor, Coast Guard officials said Monday.
Seeps occur when crude oil leaks from fractures in the seafloor or rises through seafloor sediments.
The glow was first reported Thursday night about 2.5 nautical miles off Huntington Beach, near two oil platforms, Emmy and Eva.
By Sunday morning, officials were no longer seeing sheen in the water, according to the Coast Guard, but they had pumped about 85 gallons of oil from the ocean and removed about 1,050 pounds of oily debris and tar balls from the shoreline.
The location of the leak is not far from the site of a large spill in 2021 that occurred when a ship's anchor pierced an underwater pipeline in San Pedro Bay, sending 25,000 gallons of crude oil into the waters off Huntington Beach. The cleanup of that spill lasted months and resulted in criminal charges and years of litigation.
“This situation is nowhere near what we saw in 2021,” said Huntington Beach spokeswoman Jennifer Carey. “The Coast Guard is still investigating where it came from, but they were able to clean it up quickly.”
Researchers used technology that allows them to basically fingerprint the oil they collected in the ocean and compare it to a platform, a ship, a pipeline or determine if it was the result of something that occurred naturally, the Orange County supervisor said. , Katrina Foley.
“They have a database of all the different types of crude, oil and oil generated from these different platforms and vessels, so they can compare it to a particular operator,” he said.
Coast Guard spokesman Richard Uranga said Monday that tests revealed the oil came from a natural seepage. Officials said that while it is not unusual for it to seep from the ocean floor, it is unusual to see such a large amount.
“They're used to seeing a cup of oil, not 85 gallons or more,” Uranga said. “We don't know what caused the natural leak to be so large.”
Oil leaks account for nearly half of the oil released into the ocean each year, according to the National Oceanic and Atmospheric Administration.
On Monday, tar balls continued to appear in the sand in Huntington Beach, including the popular dog beach. City officials have no plans to close beaches, but advise visitors not to touch tar that washes ashore.
One bird, a Brandt's cormorant, that had been smeared with oil died over the weekend. An ungreased but injured snowy plover, which was captured, also died. Authorities are caring for a common loon and a western grebe that were recovered with oil on their bodies.
Neighboring coastal cities have reported no signs of oil residue on their shores.
