April 20, 2010, was a day like any other. Business people went to work, children went to school, the sun shone, and, out in the Gulf of Mexico, an oil rig went about its daily work of drilling underwater wells for oil recovery. Unfortunately, that complacent normalcy could not last.

That rig, named the Deepwater Horizon, exploded on April 20, after an uncontrollable burst of methane gas shot from the well and ignited on deck. Eleven workers were killed and 17 injured, and, beneath the ocean’s surface, a leak had sprung in the oil well. That leak turned into a spill, which in turn became the Deepwater Horizon Oil Spill, commonly referred to as the Gulf of Mexico Oil Spill, the largest accidental marine spill in history, according to Encyclopedia of the Earth.org.

After numerous failed attempts to stop the oil spill, including caps and blowout valves, it was finally capped on July 15, 2010. However, the damage had already been done. In the 86 days the oil was permitted to flow unchecked, researchers estimate that about 4.9 million barrels of crude oil were released into the Gulf of Mexico.

While the extreme addition of so much oil is troublesome, the presence of oil in the ocean is far from new. Oil has actually been present in marine ecosystems for years, due to a much more natural source.

“There are natural oil leaks on the ocean floor,” said David Kirschner, the Associate Professor of Geology at Saint Louis University. “A lot of oil seeps into the ocean. To have an oil rig leaking is definitely not good, and the catastrophic-ness of the leak is far above the magnitude of what you would find naturally leaking into the sea. But there are still small, natural leaks that are always seeping oil.”

The effects of the oil spill range in scope from ecological disasters to economic pitfalls. Oxygen depletion and the toxicity of the petroleum can poison ecosystems far and wide, leading to mass deaths of marine life.

“What has been affected the most are the near shore habitats, with the oil coming up onto beaches, sitting on curbs, etc,” said Chuck Collis, the CHS AP Environmental Sciences teacher. “They’re still trying to figure out the extent of coverage under the water, because we’re just not sure at this point.”

The globs of oil circulating through the environment congest waterways and pose hazards to any animal unlucky enough to cross its path.

“It kills birds when it coats them, and it kills other animals, sea turtles and things like that, when it coats them,” Collis said. “Sometimes people are able to find these animals and clean them, but I’ve read some reports that said most of the animals that have been cleaned are going to die anyway.”

The clean-up efforts are ongoing, and include an array of deflection, dispersal, and removal techniques.

The most commonly used is containment, wherein large stretches of containment boom (specially designed barriers to hold back floating surface oil) are deployed to either corral the oil, or block it from entering marshland or other aquatic environments. The contained oil is then skimmed off and recycled for product, or burned in massive controlled fires.

These methods are only semi-effective, as the containment booms only really operate in calm or slow-moving water, which isn’t always the case in the Gulf of Mexico. In addition, the booms only corral the oil on the surface of the water. The oil goblets dispersed throughout the water itself, lower down, are not reached by these devices. Also, the use of fires to destroy the oil can be potentially harmful for any and all surrounding marine life, as well as the airborne types, as the fires emit huge clouds of smoke and gas.

“It’s pretty black stuff that comes up off of these burns, which means that there are going to be a lot of particulates,” Collis said. “I don’t know what harm these particulates are actually going to do, seeing as they’re burning them at least ten miles away from shore. You’ll also get greenhouse gases, like carbon monoxide, but much of that oil was going to be burned anyway, in cars and whatnot.”

The other technique in effect currently is that of dispersal. Airplanes are used to spray large quantities of chemical dispersants, normally COREXIT, over the oil slicks. Over time, the chemicals will cause the oil to break down far enough that it can be consumed by natural processes.

COREXIT, while effective, is also deleterious to the health of the marine life. It has been reported to cause genetic mutations as well as cancer among the animals and plants within the spray zone. In addition, the bacteria and such that consume the broken down oil molecules consume an excess of oxygen, stealing it away from the already oxygen-depleted environment.

In addition to the environmental cleanup, many have been calling for a cleanup in oil rig procedures, especially after a special report released by BP sighted eight reasons why the Deepwater Horizon originally blew up. However, many forget the true nature of drilling for oil, looking only at such catastrophic and widely covered events as the Gulf Oil Spill.

“Drilling is a hard profession, especially when you’re dealing with such depths,” Kirschner said. “There are explosions and problems probably once a month. So people who think, “Oh, It’s so easy and they just screwed up their procedures,” have never worked on a rig.”

As the cleanup efforts continue, both on- and off-shore, several wonder when the oil will be completely gone from the Gulf of Mexico. The answer from scientists? They simply do not know.

“It’s impossible to say,” Collis said. “The last giant oil spill in the United States happened a couple of years ago, and it was down in Alaska. It was completely different conditions: it’s much warmer in the Gulf, and it has more room to spread out.”

Despite this lack of a definitive timeline for the cleanup, the ocean will eventually clear up, with the coastal areas taking longer to do so.

“The damage to the ocean from the oil is not permanent,” Kirschner said. “The damage to the coastline, with the mangroves, can be, because the oil gets stored in there for a long time and doesn’t break up. But the ocean itself will be able to recover from it over time.”