Prior to this, NOAA announced in a report that almost 75% of the spilled oil is gone thanks to various causes, which is summarised as follows.
- 33% -- Clean-up efforts by human acctivities
- 25% -- Evaporated or dissolved
- 16% -- Dispersed
But wait. Is it really over? In response to this report, many scientists express concerns. Just because you can't see any remaining oil on the surface of the ocean in your vicinity, that doesn't necessarily mean no more harm. There may be bunch of oil beneath beaches or sunk onto the sea floor. It is also possible that a large amount of oil is just somewhere else, transported by complex currents, at the time of your investigation. More noteworthy is that we don't know yet very well what the long-term effects of the oil taken into the food chain are. A scientist in the above link points out that this disaster should be considered as a "3-D catastrophe", not just a 2-D problem.