Sometimes, when there's a big environmental problem that defies immediate understanding, it helps to resort to fourth grade science experiments.
In June, Carl Safina pointed out during a TED talk that he believed bombarding oil with dispersants near the spill likely helped to hide it under the surface in dilute concentrations. He took a glass of water, added oil (which floated on the top of the water), and then added dishsoap and stirred. Oil that floated on the surface of the water broke up into a cloudy mixture within the glass (video below). This was nothing like definitive proof of what was happening with oil in a complex environment like the Gulf of Mexico, just a simple experiment to support a theory about what could be going on. As reports have come out assessing how much oil is left in the Gulf, understanding the amount and movement of dispersed oil below the surface has become a bigger topic of conversation.
In the last month, scientists and reporters have expressed increased skepticism about how much oil remains in the Gulf. On August 4, NOAA released a report estimating that 74 percent of the oil had been captured, skimmed, dissolved, burned, evaporated, and dispersed. As many have already pointed out, dispersed and dissolved do not mean gone. NOAA administrator Dr. Jane Lubchenco said that the report was a release of general estimates, and not a definitive assessment. Still, scientists and reporters seeking to verify the agency's oil budget numbers have not been given the data or exact calculations for some of the results.
One new peer-reviewed scientific study offers an in-depth look at how one specific underwater plume in the gulf is behaving. A team led by Dr. Richard Camilli, of Woods Hole, surveyed a 22-mile-long plume suspended 3,000 feet below the surface of the Gulf and tested for hydrocarbons. In places they found it to be roughly a mile wide and 600-feet thick, containing minute measurements of oil and hydrocarbons. The oil was not flowing like molasses. Instead, microscopic droplets hung in the water column in dilute concentrations not visible to the human eye. Measurements suggested that it was biodegrading slowly, likely as a result of cold water temps, offering evidence that contradicted the quick break-up theory proposed in the government's report.
Oil at such depths and in such concentrations matters because scientists fear it could harm the larvae of fish and crustaceans, or that it could build up as it makes its way up the food chain and harm larger fish and mammals.
The new study offers one small piece of understanding to the large puzzle of what's going on in the Gulf. Scientists still can't say for certain why the oil exists in large diluted concentrations at such depth. They point to the depth of the spill, the cold water temps, and as Safina suggested back in June, the use of dispersants as possible causes.
“A lot of that oil, and the toxic constituents in that oil, has probably been dispersed into the water column, and that is what these scientific discoveries are finding out — there appear to be these plumes,” environmental toxicologist Ron Kendall told PopSci.
But there are no definite answers yet.
What all this means is that the exact movement of oil and the amount of oil left in the Gulf are still not completely understood. Small pieces of understanding will be added with more published studies. Until then, the only thing that is entirely clear is that out of sight should not necessarily mean out of mind.
Resources For Following the Oil Spill
The Observatory - The Columbia Journalism Review's environmental blog continues to critique the media's coverage of the spill.
Science Magazine - Veteran and award-winning science journalist Dick Kerr and colleagues follow the science of the spill.
AP Coverage of the Spill - Videos, photos, and reports from the Gulf.
Mother Jones on the Spill - Kate Sheppard, Julia Whitty and colleagues blog on the spill.
NOAA on the Spill - Reports and news from the federal agency.