GOLETA, Calif. — More than 6,000 gallons of oil had been raked, skimmed and vacuumed from a spill that stretched across 9 miles of California coast in a cleanup effort that is now going 24 hours a day, officials said, but that’s some of the sticky, stinking goo that escaped from a broken pipeline.

Investigators took stock of the scope of the spill on Wednesday a day after the pipeline break, finding that up to 105,000 gallons may have leaked out, and up to a fifth of that amount — 21,000 gallons — reached the sea, according to estimates.

Federal regulators were investigating the leak as workers in protective suits raked and shoveled the black sludge off the beaches, and boats towed booms into place to corral the two slicks off the Santa Barbara coast.

The chief executive of the company that runs the pipeline, Plains All American Pipeline LP, was at the site of the spill Wednesday and apologized for it.

“We deeply, deeply regret that this incident has occured at all,” Chairman and CEO Greg L. Armstrong said at a news conference. “We apologize for the damage that it’s done to the wildlife and to the environment.”