LET'S CUT TO THE CHASE and answer the questions foremost on your mind: Will oil from the BP Deepwater Horizon spill in the Gulf of Mexico make it to the Georgia coast?
Will the oil get into our marshes?
Unlikely, but possible.
A recent talk with several Skidaway Institute of Oceanography (SKIO) experts shed some light on these and other pressing questions in the wake of news that the oil slick had entered the so-called "loop current," which will likely take it into the Gulf Stream, on around Florida, and possibly up the east coast.
"There have been documented cases where you can trace Mississippi River plumes around into the Gulf Stream and past Georgia and beyond," explains Dr. Dana Savidge, associate professor at SKIO. "Given the quantity of oil from this spill, that does mean that it will probably get offshore of Georgia in the Gulf Stream."
Savidge describes the situation as a race of sorts. As the oil slick travels with the prevailing current, "that oil is also being consumed and transformed by light and by microorganisms," she says. "So there is some competition between how fast it gets here and how fast they are able to consume it."
Repeating the old adage that "the solution to pollution is dilution," Savidge says everything depends on the sheer volume of the spill.
"Small quantities that are naturally produced are consumed by organic microbiology. It's a matter of this spill overwhelming the system's natural ability to withstand things like that," she says.
"It's the vast amount of oil that's coming out now that is the problem," agrees her fellow SKIO associate professor, Dr. Jay Brandes. "We're reading stories today where the flow rate may be well in excess of 50,000 barrels a day. That's an incredible volume."
If the spill does make it to the Georgia coast, its path to our marshes is more daunting because of the width of our Continental shelf.
"The Gulf Stream of course is at the edge of the shelf 60 miles away. We have a nice wide shelf here that protects us from direct contact with the Gulf Stream," Savidge says. "Once it got here it would have to somehow get across the shelf, or else enter the shelf water in Florida and get here that way somehow. Those processes are pretty poorly understood."
So who will get the brunt of the spill? We've already seen images of the thick crude sludge devastating marshes in Louisiana. The sensitive coral ecosystems of south Florida are likely next, and possibly any deep coral formations along the way as well.
And after that, the Tarheel State.
"I'd say North Carolina is at great risk," Savidge says. "Their shelf is so narrow and the transport mechanisms are better defined there to get from the Gulf to their shore."
A major wild card has to do with the depth of the oil penetration in the water column.
"We don't yet have an understanding of how much water is subsurface. There's likely to be a fair volume subsurface that's completely unquantified," she says. "It could conceivably get here subsurface. The Gulf Stream extends 500-700 meters deep."
SKIO researchers gained insight into very large spills during the massive "Ixtoc 1" spill in 1979. A blowout at a well in the Gulf of Mexico run by the Mexican national oil company Pemex dumped an estimated 3 million barrels during its incredible nine-plus months of uncontrolled spewing. Almost 200 miles of Texas coastline were affected.
(Here's something for your next trivia competition: The Ixtoc 1 spill was the largest accidental oil spill in history, but the largest oil spill ever was Saddam Hussein's 1990 intentional oil spill in the Persian Gulf to discourage a U.S. landing. That spill was twice the size of Ixtoc 1.)
"After that spill, Skidaway scientists went off the Georgia coast to the edge of the Gulfstream to look for tarballs," Savidge says. "They did find some tarballs well offshore, but none within 40 miles."
Another issue in the news is the matter of the dispersant agents that are being used to spread out and break up the oil slick. Unfortunately, the dispersant is sometimes as bad or worse for wildlife as the oil is. The Environmental Protection Agency last week demanded that BP switch to a less-toxic dispersant.
"Basically the composition of the dispersant has a lot of antifreeze in it," says SKIO's Brandes. "We know that's very toxic to wildlife."
Brandes says in any case the redemptive aspects of dispersant tend to be overrated in the media, and dispersant likely just moves environmental damage from the coast to deepwater habitats.
"This isn't removing oil - this is simply dissolving it in the water column," he explains. "The compounds are still there and they're still toxic. The tradeoff is they can disperse enough of it that will limit the impact on the marshes, but it will increase the impact in the oceanic area."
So how do you handle the nimrod at the office water cooler who says, "Ah, it's no big deal. Oil is a natural product, so how bad can it be for the environment?"
It is true that oil is a natural product, and that small, naturally occuring leaks called "seeps" happen all over the world.
"But there are many things that become extremely toxic when you have large amounts of it," answers Brandes. "People also should understand when they go to the gas station and read those warnings about carcinogenic compounds in gasoline, those compounds are also present in oil. There are things in oil which are toxic to people and animals, and the kind of amounts that are being put in to the Gulf of Mexico are a real problem."
"Hurricanes are natural too, yet they kill trees and people," echoes Savidge. "It's a matter of what specific ecosystems are capable of resisting."