Officials are investigating whether a ship's anchor may have struck an oil pipeline on the ocean floor, causing the leak [Ringo HW Chiu/AP Photo]

Los Angeles, October 4 (RHC)-- Officials in the United States are investigating whether a 41-year-old pipeline caused an oil spill on the southern coast of California that has killed wildlife and tarnished much of the shoreline.

The spill over the weekend – one of the state’s largest – sent 570,000 litres (126,000 gallons) of crude oil into the Pacific Ocean and fouled the sands of Huntington Beach as well as other coastal communities.

Officials say the spill could keep beaches closed for weeks or even months, as clean-up crews dressed in white coveralls and helmets on Monday worked along a beach and wetlands running inland from the ocean on the eastern side of the coastal highway.  Birds covered in oil washed up on shore, along with dead fish.

“The beaches in many places are covered with thick clots of tar-like crude oil,” Al Jazeera’s Rob Reynolds reported from Huntington Beach, a town about 65km (40 miles) south of Los Angeles.

Huntington Beach Mayor Kim Carr said some 34 square kilometres (13 square miles) of ocean and portions of the town’s coastline were “covered in oil."  Officials on Monday were reportedly looking into whether a ship’s anchor may have struck an oil pipeline on the ocean floor, causing the leak.

Amplify Energy CEO Martyn Willsher, the head of the company that operates the pipeline, said on Monday that divers have examined more than 2,438 metres (8,000 feet) of pipe and are focusing on “one area of significant interest”.

A ship’s anchor striking the pipeline is “one of the distinct possibilities” for the cause of the leak, he said during a news conference.   U.S. Coast Guard officials said that cargo ships entering the twin ports of Los Angeles and Long Beach routinely pass through the area.

“We’re looking into if it could have been an anchor from a ship, but that’s in the assessment phase right now,” said Coast Guard Lieutenant Commander Jeannie Shaye.

Federal officials have stepped up scrutiny of ageing and idled offshore energy pipelines. Energy companies have built 64,000km (40,000 miles) of oil and gas pipelines in federal offshore waters since the 1940s.

In March, the U.S. Government Accountability Office (GAO), a governmental watchdog, found that regulators have failed to address the risks from idled pipelines, platforms and other infrastructure on the sea floor.  “As pipelines age, they are more susceptible to damage from corrosion, mudslides and sea floor erosion,” GAO said.