A Penn State researcher collaborating with Spanish scientists has developed new techniques that may lower the environmental impact of oil spills around the world.

In November 2002, the oil tanker Prestige, which carried more than 77,000 tons of crude oil, wrecked off the northwestern coast of Spain. Now, more than two years later, there is still some oil remaining and slowly leaking from the sunken ship, said Bernd Haupt, senior research associate at the Earth and Environmental Systems Institute at Penn State.

Haupt, who collaborated with Almudena Aguero, a senior scientist from the Research Centre in Energy, Environment and Technology (CIEMAT) in Madrid, used computer models and studies of ocean, oil and sediment movement to determine the long-term behavior of oil and oil leaks, he said.

They also studied the effects of water depth and pressure on hulls in sunken ships, he said.

Aguero approached Haupt to assist the Spanish team in studying the wreckage because of his background in sediment transport modeling, Haupt said.

Aguero explained in an e-mail message that this spill -- which was twice as expensive as the Exxon Valdez spill of 1989 -- received a great deal of media attention in Europe, though not nearly as much in the United States.

In addition to the environmental effects of the spill on the ocean and Spanish coastline, it also affected nearly the entire local economy, which is based on tourism and fishing near the coasts, Aguero said.

Furthermore, as the tanker remains underwater, the hull is slowly rusting away and more oil is leaking out, even though original leaks were patched, Haupt said.

Aguero said that another factor that makes the Prestige spill unique is that the wreckage rests at a depth near 12,000 feet -- a much greater depth than most wrecked tankers.

Under normal conditions, a hull will last 20 years before it begins to rust through, but certain bacteria found around the wreck accelerate the degradation of the hull to about four years, he said.

Haupt said that given these factors and the effect the oil spill continues to have on the local economy, their research has revealed how much oil is left in the tanker and a possible rate of leakage.

This new information may allow for new methods to be employed to combat the slow seepage of oil, he said.

Haupt said one solution would be to drop a granular material from the ocean's surface onto the ship's remains, which would form a seal around the wreckage and absorb leaking oil.

This material would speed up the rate at which the wreckage is covered by the ocean floor, he said.

The team is currently studying sedimentation rates and data on ocean currents to help cleanup crews determine a precise spot at which to dump the material, Haupt explained.

"The current sedimentation rate is about one centimeter every 1,000 years," he said. "It could take over 100,000 years to cover the wreckage and prevent leaking, and in this case, we can't wait for nature."

Haupt said that soon after the wreck occurred, the Spanish government used collection bags in an attempt to remove the remaining oil from the sunken ship. As the bags fill, they rise to the ocean surface because of the properties of oil in water.

Unfortunately, the companies contracted to remove the oil removed only a fraction of the actual amount that was left in the hull, Haupt said.

"They want to say they are the heroes here and got everything out" of the wreckage, he said.

Sometimes, the hauling companies report a smaller quantity of oil than they are actually carrying to save insurance money, Haupt said.

In addition, those companies contracted to remove the oil are never responsible for an exact amount of oil and can report the tanker empty far before it actually is in order to collect their payment sooner, he said.

Aguero said evidence from their research suggests that there is anywhere from 16,000 to 23,000 tons of oil remaining in the tanks, which is contrary to the 1,500 tons that the extracting company says remains in the wreckage.

Even if more oil is removed from the wreckage, some oil will remain, unable to be removed, Aguero said. As a result, neutralization methods aided by their research will eventually prove to be the best solution, he said.

Although this research may be focused on this wreck, its benefits may be seen all over the world in the future, Haupt said.

"All people and all the environment will benefit," he said. "If you can help prevent such disasters or minimize their impact, that's a really big thing."

Aguero cited the environment as the biggest benefactor of their research.

"Because our environment is a matter for everybody," he said, "everybody will get an advantage from a better solution to solve these environmental problems."

The main goal of this research is to offer a set of treatment guidelines, "much like medical professionals know immediately the correct way to treat someone with a heart attack," Haupt said.

"With oil spills, you have to react fast, so we hope to come up with guidelines and have methods ready that someone can immediately apply," he said.