Gulf oil spill: Not as bad as we first thought?

With oil no longer flowing from the Gulf blowout, and green shoots beginning to appear in some patches of marshland where oil from the damaged well made landfall, scientists are beginning to note a few, tiny, early signs of the environment's recovery from the disaster.

They caution that recovery will take from years to decades. Much depends on where the remaining oil and methane from the blowout lurk as they disperse and await the natural processes that break them down.

And if history is any guide, some habitats that look "restored" to the untrained eye may not support the same mix of organisms that thrived in them prior to the blowout.

IN PICTURES: The Gulf oil spill's impact on nature

Still, the federal government has opened roughly one-third of the federal waters in the Gulf it had closed to fishing. At week's end federal officials sounded a conditional all-clear for southern Florida, the Keys, and the state's east coast – a region long concerned that the Gulf's loop current would sweep surface oil into its flow and daub the state's coastal areas with crude. The condition? That the flow from the well remains stanched.

These small bits of encouraging news don't surprise scientists who have long studied the effects of oil spills, says Edward Overton, an environmental chemist and professor emeritus at Louisiana State University (LSU).

Oil spills and blowouts "are horrible. There is carnage everywhere during the event," he says. Because so much of the oil, methane, and dispersants has remained deep in the ocean during the Gulf blowout, "there is damage that you and I can't see, and it won't be obvious for several years, maybe a decade or two."

Still, he adds, once the oil is cleaned, the environment begins to recover fairly quickly.

It's often the case that when researchers and other specialists face an accident that has little or no precedent, the initial tendency is to steel for the worst. Overestimating the potential effects risks the finger-wagging that comes with 20-20 hindsight. Underestimating the effects, however, risks far more.

When an accident pumps 3 million to 5 million barrels of oil into the Gulf, "you can't understate the impact and gravity of the situation," said retired Coast Guard Adm. Thad Allen, who heads the federal response effort, last week during a press briefing.

"I think anybody that classifies this as anything less than catastrophic isn't being realistic. The American people would expect an overabundance of caution," he said. "While we'd all like the area to come back as quickly as possible, the fact is that in the history of our country we've never put this much oil in the water."

Nor has the country put this much dispersant in the water.

"We can't say yet what the effects of 2 million gallons of dispersant will be," adds Thomas Shirley, a marine biologist at Texas A&M University at Corpus Christi.

Quick recovery?

Several factors argue for the potential of a relatively quick recovery for some sea species that may have been affected, some researchers say.

The federal and state bans on fishing reduced the human pressure on fish stocks this year. And at least on or near the surface, an expected increase in bacteria munching on the remaining oil could increase the food available for organisms higher up the food chain, making the area an attractive feeding ground for sea birds and fish. Oil does not work its way up the food chain as other compounds, such as mercury, do.

Yet much remains unclear about conditions under the surface, including the number of animals for whom the oil and dispersants already have proved fatal.

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