Efforts to mop up the oil spill that smudged nearly 20 miles of Orange County's coast began to wind down Sunday as rain-soaked work crews turned their attention to scrubbing seaside boulders and gathering oil-stained flotsam driven ashore by the weekend's storm.
While rains hindered the cleanup, heavy surf whipped up by the storm appeared to help scour oil from jetties and rock formations along the coast, authorities said.
"There's still a bit of work to do, but we're out of that high-pressure, high-impact phase and into the more detailed work," said Chief Warrant Officer Dan Dwell, a U.S. Coast Guard spokesman.
In Huntington Beach, some oil washed ashore in a foamy film, but workers were mostly finding tar balls no bigger than jelly beans along scattered stretches of the coast. The crews also busied themselves gathering branches and other debris, piling it into huge mounds that gave the beaches the look of hayfields.
Booms that had been tattered by the weekend storm were put back in place or replaced on the Newport Harbor entrance and Santa Ana River mouth.
Newport Bay was expected to open today, but with a boom gate at its entrance that a skiff will open to allow individual vessels through. Authorities, however, decided Sunday to postpone rebuilding a sand berm on the mouth of the rain-swollen Santa Ana river.
Beaches from Newport Beach through Bolsa Chica remained closed because of the spill. As cleanup work continued, the oil tanker American Trader, which spilled 394,000 gallons of crude oil Feb. 7 when it impaled itself on its anchor while attempting to moor off Huntington Beach, steamed out of the Port of Long Beach late Sunday afternoon and headed to a San Francisco shipyard for repairs.
Coast Guard officials gave the ship permission to head to the Southwest Marine shipyard after inspecting a temporary, concrete patch fitted over two holes in the craft's hull.
Meanwhile, Coast Guard officials continued to puzzle Sunday over a mysterious oil sheen that washed ashore during the weekend.
Coast Guard investigators have yet to determine the origin of the latest oil sheen, which appeared different than that of the crude that gushed from the American Trader. Officials also suspected that the sheen might be from a different source because the tanker's crude had been drifting south, while this oil came ashore farther to the north.
The mess left by the sheen along a milelong section of Bolsa Chica State Beach was cleaned up by Sunday afternoon. Several samples of the oil were dispatched to the Coast Guard Oil Identification Laboratory in Groton, Conn., to determine whether it matched the oil spilled by the tanker.
Dwell said there is speculation that the source of the latest sheen may have been a small leak from one of the oil rigs off Huntington Beach or a spill from a tanker pumping its bilges.
Huntington Beach Mayor Thomas J. Mays said he was troubled by such a possibility, saying he hopes "someone didn't take advantage of this situation."
Mays flew over the remnants of the American Trader spill Sunday and said he saw only a few oily patches and scattered sections of sheen in the ocean.
But Mays said he is particularly eager to ensure that crews mop up any oil and tar that has percolated into the sand.
Charles Webster, a spokesman for British Petroleum, said that cleanup officials "don't anticipate much under the surface" but acknowledged that crews have found "a few locations" where oil has been found up to six inches below the beach surface.
On Sunday, teams were taking core samples at regular intervals along a 14-mile stretch of beachfront from Newport Beach to Bolsa Chica to assess how much oil has seeped below. When the extent of the problem is determined, British Petroleum will either clean the sand or replace it, officials with the company said.
As the extent of oil washing up on beaches declined in recent days, the number of cleanup workers also was reduced. On Sunday, 320 workers patrolled the shoreline, down from 470 on Saturday and 635 Friday. At the peak of the cleanup last week, more than 1,400 workers were deployed.
Webster said that the crew is expected to be down to about 100 workers later this week but that when the mop-up is concluded, British Petroleum will keep an oil cleanup firm on standby in case of new problems.
Much of the focus now will shift to removing oil from breakwaters, jetties and other rock formations along the coast. Although steam was used to clean rocks in Alaska fouled by the Exxon Valdez spill, that tactic has been rejected for Orange County because of fears that it would kill sea creatures lurking among the boulders, Newport Fire Capt. Ray Pendleton said.
Instead, authorities are trying to use saltwater heated to 82 degrees, hoping it will melt the oil while not harming mussels and other marine life, he said.
As of Sunday afternoon, 299 birds had been reported dead from the spill, and another 425 were found alive but covered with oil.
In addition, the second dead dolphin in two days washed ashore Sunday, reviving concerns about the episode's impact on sea life.
John Heyning, curator of marine mammals at the Los Angeles County Museum of Natural History, said it remains unclear what caused either dolphin to die, noting that such "strandings" are not uncommon in Southern California waters. Tests to determine whether the spill played a part will be performed Tuesday or Wednesday, he said.
Heyning said the seven-foot-long Pacific white-sided dolphin found dead Sunday was not covered with oil when it was recovered.
Meanwhile, a sheen of oil was discovered on the waters of the Bolsa Chica and Huntington wetlands, but authorities said it appeared that the film was a result of runoff from nearby roads. Workers had contained the sheen with oil-containing booms.
Staff writers Dan Weikel and Ted Johnson and correspondents Tom McQueeney and David Burke contributed to this story.