Every day since the accident, hundreds of thousands of gallons of crude oil have leaked into the Gulf of Mexico. While BP is attempting to stop the flow of oil, the oil that has already leaked must be dealt with too.
Bacteria will eventually eat the oil, but it will take a long time for the millions of gallons of escaped oil to be consumed. In the meantime, surface oil slicks and oil drifting underwater are toxic to the plants and animals it comes in contact with, so people are doing their best to prevent it from ever reaching shore.
Floating “booms” are helping contain some of the oil slick. Booms work like a floating wall, keeping the oil from spreading past them. But waves and rough water can splash oil over the booms. Some of the oil is being skimmed from the surface, and, when possible, some of it is even burned away before it can reach the shore.