As children many of us read Dr. Suess’s the Cat in the Hat Comes Back where we were introduced to VOOM. For those who didn’t read it or don’t remember after wrecking the bathroom with a pink ring in the tub the Cat keeps calling on more Little Cat Assistants to help clean up the pink mess. Each assistant makes matters worse until the whole house, even the snow outside, is covered in pink. In fact, one might say that the pink mess was dispersed all over the place. Then the last and smallest assistant, Little Cat Z, uses VOOM and just like that the mess is cleaned up and all of the assistants are blown back under the Cat’s hat.
So perhaps you are wondering why I am relating VOOM to the BP Gulf oil spill? As the world watched over the spring and summer BP tried one failed attempt after another to stop the flow of oil from their blown well in the Gulf. I could not help but be reminded of the Cat’s assistants, spreading the mess. Then on July 15th, BP got a cap in place and the flow stopped. We were warned by the government and the press that this was not the final solution. However, for all intents and purposes, particularly for keeping a spotlight on BP, it was the final solution.
Quietly, and without the attention from the media, that you might have expected given the magnitude of the spill, on September 19th BP successfully completed the permanent closure of the well. The flow of oil from the well had stopped on July 15. In the intervening weeks between mid July and mid September the attention of the national media and with it the nation turned to other things. There was no more spectacle, no more 24 hour a day video of oil steadily pouring out from the damaged well.
However, a looming and hotly debated question since has been, where did all the oil go? Scientist and experts are very divided on the answer. The US government contends that the majority of the oil is gone. They provide the following estimates:
- 33% of the oil was recovered, burned or dispersed
- 25% of the oil naturally evaporated
- 16% of the oil broke down naturally
- 26% of the oil is just below the surface or washed up on shore
Figure 1 is an excerpt from the NOAA report “BP Deepwater Horizon Oil Budget: What Happened To the Oil?”, where additional details can be found.
Yet, to say the oil is dispersed, whether naturally or through the use of dispersant, doesn’t really answer the question of “Where did it go?”.
Some point to rapid degradation by natural oil consuming microorganisms. It makes a kind of logical sense that in a region subject regularly to natural oil seepage there would be an abundance of natural organisms capable of breaking down oil. One of the fundamental principles of bioremediation is to enhance the environment to support the activity of naturally occurring microorganisms, rather than trying to introduce tailored organisms to consume contaminants. However, the natural environment in the Gulf was not enhanced.
Concern was raised that when combined with the expected seasonal increase in biological activity in the Gulf, increased activity of petroleum consuming microbes would result in a large area of water with depleted oxygen. When measurements were taken the expected zone of depleted oxygen was not found. So what does that mean? Some postulate, there is insufficient depletion of oxygen to indicate the level of increased biological activity that would accompany the break down of the amount of oil spilled in the Gulf. Others have speculated that because of the dispersants the biological activity was less concentrated and therefore still occurred but without depleting the oxygen.
In August researchers from University of South Florida found significant deposits of crude along the seabed floor. Additionally, they discovered microorganisms in the area had been affected by the oil.
Subsequently, in September researchers from the University of Georgia also found areas of seabed heavily impacted by oil (read the AP press release “Where’s the Oil? On the Gulf Floor Scientist Say”). A third research team, from Texas A&M, also reported finding oil from the Macondo well 3000 feet below the ocean surface, 300 miles away from the well. This raised increased skepticism concerning the governments claims regarding the fate of the released oil. Many believe a much larger quantity of oil than estimated sunk, as a result of the depth of the initial release and the heavy use of dispersants. There is concern that oil on the seabed floor has the potential to impact many species via the food chain. Many of the lower level species in the food chain originate on the seabed. Plans are underway to study this further.
Many have pointed to learnings from the Exxon Valdez release. One of the main points made is, still some 20 years later, residual oil can easily be found on the shores around Prince William Sound. In most instances you have only to overturn rocks or dig into the sand and sediment a few inches to uncover this oil. In some places the weathered oil is plainly visible without digging or overturning anything. The second point is that some of the significant species impacts were not seen for up to 3 years after the spill. In order to determine species damage more than one breeding cycle may be necessary. The Pacific Herring disappeared from Prince William Sound three years following the Valdez spill. Evidence, is not conclusive that the disappearance is related to the spill but most have concluded that it is related. Certainly, the conditions in Alaska were and are different than in the Gulf. The Valdez release was a surface spill into a sheltered body of water and the normally cold Alaskan weather conditions are not conducive to the type of natural pollutant degradation expected in the Gulf.
What does seem to be the case however is, at this juncture, no one is certain where the oil from the Gulf spill went. In fact, there isn’t even full agreement on the quantity of oil released. Though, there is emerging consensus that at least 4.4 million barrels (205 million gallons) were released. The area, both the environment and the ecology, will need to be studied for some years to come to really assess where the oil went and what level of natural resources were damaged by the spill. I suspect that at the conclusion of those studies BP will not actually have found VOOM.