Huntington Beach: Anchor theory after huge oil spill off California

Cleaning crews pick the tar from affected beaches

US investigators are looking into whether a ship's anchor may have struck a pipeline on the ocean floor after a huge oil slick off California.

The spill sent up to 126,000 gallons (573,000 litres) of heavy crude into the ocean off Huntington Beach.

It then washed on to miles of beaches and a protected marshland, killing fish and birds, contaminating wetlands and leading to beach closures.

A state of emergency has been declared in Orange County.

The slick, about five miles (8km) off the coasts of Huntington Beach and Newport Beach, was discovered on Saturday morning. Popular beaches along a 15-mile stretch of coastline south of Los Angeles have been closed.

It is thought to be one of the largest oil spills in the state's recent history.

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Martyn Willsher, CEO of Amplify Energy Corp which owns three offshore platforms, said it was possible a ship anchor could have struck the pipeline.

The US Coast Guard was assessing whether one of their anchors could have hit the line, said Captain Rebecca Ore. "It is possible they would transit over a pipeline," she was quoted as saying by Reuters news agency.

When the spill was discovered will also be investigated, said Orange County Supervisor Katrina Foley: "Mariners and other were reporting they saw a sheen on Friday night."

Amplify said it had stopped operations and shut its pipeline on Saturday. Mr Willsher said the pipeline had been suctioned to ensure that no more oil would spill.

Governor Gavin Newsom, who ordered the state of emergency in Orange County, directed state agencies "to undertake immediate and aggressive action to clean up and mitigate the effects" of the spill.

Some 2,050ft (625m) of protective booms, which help contain and slow the oil flows, have been deployed, and about 3,150 gallons were recovered on Sunday, the US Coast Guard are quoted by Reuters as saying.

The Deepwater Horizon rig disaster in 2010 caused the deaths of 11 crew and a massive oil spill in the Gulf of Mexico.

There were also other longer-term impacts on marine life including impaired reproduction, reduced growth, lesions and disease.