In 1979, the collapse of the Ixtoc 1 rig emptied about 140 million gallons of oil into the Gulf of Mexico. Two months after the explosion, the oil landed on Padre Island, Texas. There was a strip 170 miles long and 30 feet wide -- it looked like a paved highway.
Many in San Padre thought the area would never recover, but it did.
"To my amazement, we saw recovery right away in some places. But in others, we can still see evidence. The shrimp came back in about two years," said Wes Tunnell, a marine biologist, ecologist and self-described optimist, who has studied the impact of oil spills for decades.
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Tunnell says that the same could happen to the areas affected by the BP oil spill in April although it will likely take a little longer.
"The Gulf of Mexico is a hugely resilient body of water. There's the equivalent of one to two supertankers per year that seep into the Gulf of Mexico waters naturally. It populates the entire Gulf of Mexico with petroleum-eating bacteria. There's lots of them out there munching away on this oil all the time," Tunnell said.
"The difference in the northern Gulf of Mexico beaches is that their energy, their wave energy, is less than it is on the Texas coast. The wave energy helps in breaking the sand and the oil that's there. ... I think that's going to take place a little slower in Mississippi, Alabama and western Florida where the oil is on the beaches. So three to four years but it will recover," he said.
Tunnell said it surprised him and the Ixtoc spill cleanup crews that 2 1/2 years after the explosion, the area had recovered well.
"For most of us, it was the first major spill to deal with, we were just flabbergasted. As I see my colleagues today in the northern Gulf of Mexico that see all the oil coming in, that 'oh no, this place is going to be wiped out for years, decades or maybe forever.' That was our concern then but we were equally amazed at what happened to 140 million gallons of oil," Tunnell said.
Oil Spills: A Glance at History
In 1967, the Torrey Canyon tanker spilled 36 million gallons of oil off the coast of England. To burn the oil, the Royal Air Force dropped 161 bombs and 3,000 gallons onto the slick. It was the world's first massive oil spill.
"They didn't even dilute [the chemicals]," Tunnell said.
Forty-three years later, the consequences of that disaster are still evident. In a quarry, where all the oil from the Torrey Canyon was dumped, animals are still dying.
In America's first major spill, in 1969, 4 million gallons of oil washed ashore in Santa Barbara after a platform blowout.
"It was really the wake-up call," Tunnell said of the Santa Barbara oil spill. "Earth Day actually started because of this."
In Massachusetts' Buzzard's Bay, where there have been close to 10 major oil spills since the 1940s -- the most recent occurring in April 2003 -- scientists have found that the fiddler crab is chronically impaired, seemingly drunk on oil.
And in Alaska, where the 1989 Exxon Valdezoil spill released close to 11 million gallons of crude, the herring population still has not fully recovered. Twenty-one years later, a thick, oily residue can be found in much of the rocky coast of Prince William Sound and more than 21,000 gallons of oil infest the shore.
In the case of Ixtoc, Tunnell said the U.S. and Mexican governments ceased funding research when the cleanup effort ended. He said that while Exxon was forced to fund studies, not many others in the oil industry have given money for that purpose. According to Tunnell, since the spill in April, BP has given $500 million for such studies.
"An oil spill is a big experiment that we should take advantage of. It's an opportunity -- it's a very, very sad opportunity [for] those of us who have been studying the environment and training students. ... When it occurs, it's an experiment for us to study to see what the impacts are on all aspects of the environment," Tunnell said.
BP Oil Spill: Normal Life Should Return in 5 Years
Tunnell said tourism would return to the Gulf area in about a year but that it would take five years for the beaches to recover. He did not think the shrimp industry would die, as many local fishermen have feared.
"If [the dispersants] do their job, then the process of degradation takes place faster so it may not affect the shrimp on the bottom," Tunnell said. He was not so sure about the oysters.
"That's a difficult call. That's where it gets into the oyster reefs, and that's different from the oysters on the roots of the red mangroves (in Texas). They're growing on oyster reefs that might be right up at the surface, or several feet deep. If those get heavy oil, that would be impossible to clean up," he said.
Tunnell said it will take decades for th eoil to be completely gone from all habitats.
When Tunnell returned to Mexico this month, 31 years after the Ixtoc spill, he found oil tar in the marshes. Fishermen said that the oysters still had not returned, but the shrimp catch was like it was before the blast.
"The oil went into the shorelines where oysters are and directly hit the oysters on the roots of the mangrove trees, whereas shrimp live on the bottom and oil floated primarily on the surface. And so it went onto the shoreline from there, so the shrimp probably missed the majority of the oiling," he said.