The way that it was cleaned up was by dispertants. It's a mixture of chemicals that helps breaks down the oil into smaller particles to help it mix with water better. But the thing about dispertants is that when it is mixed with the oil, it becomes more harmful than the oil by itself. So there really isn't any upside to using it. For this spill, they injected it directly into the well to stop the leak (6).
Oil spills can damge many species of animals long term. Like sea turtles for example. Baby sea tutles entering the water or trying to get there can get stuck in the oil on land or in the water and end up sufficocating. the oil can also damage the eggs and they fail to develope properly. It also kills dolphins, whales, sea otters, seals, and birds (20). From the BP oild spill alone, 90% of the 40 large groups of coral located near the well was discolored, damaged, dead, or dying (9).
Our Oil Dependence
Oil spills are only the symptoms of the bigger problem. The U.S. has a large dependence on oil and because of this, much damage is being done to oceans. Instead of investing on oil here in the U.S., we spent about $1 billion daily on about 4 million barrels in 2008 (12).
If we didn't rely so much on oil for our energy source, oil spills would be more uncommon because we wouldn't have such a high demand for importing it. There is a direct correlation between the amount of oil needed and the amount of oil spills.