ARTEIXO, Spain -- The whipping wind and rain in temporary respite, Xose Ferreira adjusts his goggles and mask and trudges over the sand dunes with a shovel. A week after the oil tanker Prestige split apart off the coast here, the once-pristine beach is littered with cloying, crusty pools of oil. The rocky cliffs that bookend both sides of the beach are tar-stained to a height of more than 15 feet.
"The cold and the rain isn't so bad, actually," Mr. Ferreira says. Worse are the fumes. "When the sun hits the oil, the vapors coming off can really do a job on you," he says.
Mr. Ferreira is a front-line soldier in an ecological battle between man and oil, a battle that oil will probably win, if experience of past spills is any guide. After years of studying spills including the 1989 Exxon Valdez accident off Alaska, scientists have come to the surprising conclusion that most efforts to clean up a major oil spill do precious little good -- and sometimes do harm.
The Bahamas-flagged Prestige was carrying almost 85,000 tons of oil, a heavy, sticky grade of fuel that is making this spill, off the northwest coast of Spain, worse than many others. Conventional techniques, such as scattering straw or foam on the water to make the oil thicker and easier to scoop up, won't work.
"The Prestige oil is like chewing gum. Why would you want to make it thicker?" asks Ian White, a marine biologist and managing director of the International Tanker Owners Pollution Federation, an industry body that advises on cleanup techniques. "Once the oil spreads on the water it becomes a phenomenon that's very hard to control. You're fighting nature, and nature wins a lot."
Experienced spill-fighters know action can't be fast. They want to avoid aggressive techniques that could further harm the environment, even while seeking the most cost-effective way to restore the environment to its previous state.
The fundamental question is: How clean is clean? "The first 90% of any cleanup comes easy. But the tradeoffs for the remaining bits are brutal and can sometimes do more harm than good," says Gary Shigenaka, head of the National Oceonographic and Atmospheric Agency unit that scoured the coves of Prince William Sound after the Exxon Valdez spilled more than 250,000 barrels of oil in 1989. The last 1% of oil removed can cost seven times as much as the first 99%.
The lessons in Alaska were sobering. Mr. Shigenaka found that in a crude oil spill, doing almost nothing -- helping nature break up and disperse the oil by itself -- may be more effective and possibly less harmful. For instance, using sand blasting and abrasives to clean the coast also disrupted critical soil biology, he found. Today, both the "stand alone" areas and the aggressively scrubbed areas are on the same path to recovery, he says.
The least destructive method is using booms and skimmers to recover floating oil, spill experts say. But only 10% to 15% of the oil can be scooped up this way, even in the best conditions, and less than 5% when winds and waves are high, as in Galicia. The Prestige's heavy grade of oil makes this method even less effective: Heavy oil forms blocks more than three feet thick that are hard to scoop and lift. The Prestige's cargo was so-called Russian M-100 grade, a heavy fuel burned in marine engines and a custom-made blend of additives and toxins that adds to the cleanup difficulties.
Another possibility is chemical dispersants, or solvents, sprayed from planes or boats. Waves and wind naturally break a slick up into droplets; the chemicals can accelerate the process by reducing the surface tension between oil and water, causing the oil droplets to sink beneath the surface. But dispersants have little effect on viscous oils like the Prestige had. The heavy fuel oil tends to mix with seawater, forming sludge.
That makes it pointless to try to burn the oil while it floats on the sea surface. First, the workers would have to corral the oil into one place -- not easy in turbulent seas. The Prestige oil also won't ignite easily: The lighter hydrocarbon compounds, which burn easily, were removed in making the fuel. And burning produces lots of black smoke, plus a toffee-like residue that is difficult to recover from both sea and shoreline.
Another tactic: Spread bacteria on the oil to eat it up and degrade it into simpler compounds like carbon dioxide and water. In practice, though, the bacteria can be diluted and lost. And this method takes a long time. Mr. White of the tanker-industry group, estimates that even the addition of extra bacteria and nutrients "will only speed up the process to six months" from the natural time-frame of one year.
Despite the debate, the cleanup must go on. Most locals want immediate action. Fishing has been banned in the worst-hit areas, and many shell-fishermen are watching their crucial Christmas season drown under a sea of sludge. Environmental groups are working overtime to save the few hundred birds trapped in the oil. And hoteliers and restaurant owners in this region that literally lives off the sea are demanding fast action and some form of compensation from the government.
Volunteers are shoveling tons of tar-colored sand into pails and plastic bags along a 183-mile stretch of the Spanish coast, part of the cleanup's "emergency phase." Later will come the "polishing," the expensive, time-consuming efforts to wipe oil off rocks and in sheltered coves.
The spill, encompassing an estimated 19,000 tons so far, will cost at least $42 million to clean up, the Spanish government says -- and that's before coping with the rest of the 66,000 tons of toxin-laden oil still trapped 2.2 miles down, inside the sunken tanker. Authorities have yet to decide on their full cleanup strategy. The implications are huge. Europe sits astride shipping lanes that move billions of gallons of oil each year; about 70% of the oil leaving Europe passes these Galician shores. Accidents, like the gale that ripped a 20-meter breach in the Prestige's hull last week, are inevitable.
If stormy conditions persist, much of the oil will be broken into smaller bits and dispersed by ocean currents. In calmer areas of sea, floating booms will do some good. And for the oil that does wash up on the shore, people -- armed with buckets, spades and bulldozers -- may have to clear up as much as they can. "It's primitive technology, but it's the only way, I'm afraid," Mr. White says.
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