GOLETA, California (AP) — More than 8,300 gallons (31,418 liters) of oil has been raked, skimmed and vacuumed from a spill that stretched across 9 miles (15 kilometers) of California coast, just a fraction of the sticky crude that escaped from a ruptured pipeline, officials said Thursday.

Up to 105,000 gallons (400,000 liters) may have leaked from the pipeline Tuesday, and up to 21,000 gallons reached the sea just northwest of Santa Barbara, according to estimates from the pipeline operator.

The environmental impact was still being assessed, but there was no immediate evidence of widespread harm to birds and sea life.

The early toll on wildlife included five oil-covered pelicans, which were taken in to be cleaned, officials said. Biologists counted dead fish and crustaceans along sandy beaches and rocky shores.

The spill occurred along a long, rustic coast that forms the northern boundary of the Santa Barbara Channel, home to a rich array of sea life. Whales, dolphins, sea lions, seals, sea otters and birds use the waters between the mainland and the Channel Islands, five of which are a national park surrounded by a national marine sanctuary.

The coastline was the scene of a much larger spill in 1969 — the largest in U.S. waters at the time — that is credited with giving rise to the American environmental movement.

Workers in protective suits shoveled black sludge off beaches, and boats towed booms into place to corral two oil slicks. The number of cleanup workers surpassed 300, and the number of boats working the slicks rose to 18, officials said.

They could get help from expected light winds and calm seas, said Sean Anderson, an environmental scientist at California State University, Channel Islands.

"When the water's choppy, the response gets complicated. But since the water's nice and flat, the oil sticks together and it's easier to spot and easier to pick up," he said.

Coast Guard Capt. Jennifer Williams said the slicks were moving seaward, not toward other beaches.

Regulators and workers with Plains All American Pipeline LP, which runs the pipeline, aimed to begin excavating the pipe Thursday to get their first look at the breach. The company also was removing contaminated soil.

Federal regulators were investigating the cause of the leak and the pipe's condition.