Sensitive nesting sites

Volunteers carry buckets of oil from an oil slick along the coast of Refugio State Beach in Goleta, California, United States, May 20, 2015. [Photo/Agencies]

Still, Janet Wolf, who chairs the Santa Barbara County Board of Supervisors, called the latest spill "a disaster" and "a worst-nightmare scenario."

Wildlife teams were dispatched to the scene to rescue any sea birds, marine mammals and other animals injured by the spill, but authorities said the extent of damage to wildlife was not immediately known.

Crews were focusing on three especially sensitive sites known as nesting areas for shore birds, including snowy plovers and least terns, said Alexia Retallack, a spokeswoman for the California Department of Fish and Wildlife.

Refugio State Beach and adjacent campgrounds were to remain closed to the public through the Memorial Day holiday weekend, officials said. The area was also closed to fishing and shellfish harvesting.

At daybreak, about 130 cleanup workers contracted by Plains were on beach scooping up globs of oil from the sand, raking up tar balls and disposing of the material in plastic bags.

Crews will also scrub soiled rocks, hose down contaminated areas and skim up oil left behind, Coast Guard Captain Jennifer Williams told a news conference on Wednesday in nearby Goleta.

Nine cleanup vessels plied the ocean, six of them corralling the slick with booms and three others skimming up oil from the surface. By about 8:30 am, crews had managed to recover about 120 barrels of spilled crude, most of that from the beach, officials said.

The pipeline that burst on Tuesday typically carries about 1,200 barrels of oil an hour from Exxon Mobil's Las Flores Canyon processing facility to a distribution hub in Bakersfield hundreds of miles away, company and county officials said.

The company said an internal inspection of the pipeline was conducted a few weeks ago but results had not yet come back.