BP announced that as of July 17th, approximately 807,000 barrels of oil have been skimmed from the gulf. That is an increase of 133,500 barrels of oil since their last report on July 5th. That works out to over 11,000 barrels of oil skimmed per day. That implies that the rate of oil collected has been increasing.
There were several days in the period where weather conditions in the gulf caused high wind and waves that shut down most skimming operations. This would imply that the daily collection rate in good weather has increased.
I have been looking for more detail on which skimming operations and equipment have been responsible for the most oil collected. Dutch mechanical skimming arms are in use on some ships. Other equipment like barges with pumps on them have been put into use collecting oil. Boats with absorbent booms continue to be used. If anyone has any information on specific oil collection amounts, please share it in the comments.
I have seen reports that the Dutch skimming arms were attached to a 20,000 ton foreign ship, but then were not used. The government forced the arms to be moved to a 1,000 ton U.S. flagged ship, which would be very small for this equipment. The use of a foreign ship would violate the Jones Act. The president has the power to wave the Jones Act, but has not done so. This make me wonder if equipment like the Dutch skimming arms are really being used effectively? I do not know the answer, but the truth will eventually come out.
Now that the flow of oil into the gulf has been stopped, the amount of oil in the water will decrease each day. Skimming and burning will remove some of the oil. Some of the oil will simply evaporate. Burning will only work with fresh oil so I expect that will soon stop.
Over time, naturally occurring bacteria will eat much of the oil. Each day the oil stays in the ocean, the amount of oil will decrease. The most volatile compounds in the oil are the first to be neutralized. These are the compounds that also cause the most environmental damage. The smell from the oil is these compounds evaporating. The oil becomes more viscous over time and eventually reaches the point of forming tar balls. These tar balls can was up on beaches, but are too viscous to penetrate into the soil and will pose little harm to plant or animal life.
The marshes in Louisiana have been contaminated with crude oil that will seep into the ground where bacteria and air will have a difficult time neutralizing it. Cleaning up the marshes will be difficult work. The more oil that we can remove from the marshes, the faster nature will be able to clean up the rest.
In Florida, oil washes up on the beaches mainly as tar balls. The oil has traveled so far and been in the water so long that it is much more viscous, will do less environmental damage and be easier to clean up.