Last week, researchers from the Florida State University released a new study, reporting that there are anywhere from six to 10 million gallons of crude oil from the Deepwater Horizon disaster settled into the floor of the Gulf of Mexico. With a ruling looming in the future regarding fines under the Clean Water Act, BP is none too thrilled about the news. The company issued a rebuttal via The State of the Gulf, a website BP created in the wake of the Gulf oil spill.
BP’s response purports that the study is false and problematic. The scientists’ methods, it states, are flawed, meaning the data doesn’t support the final estimates provided.
Instead of using rigorous chemical analysis to identify oil in sediments, the researchers used a tracer common to all sources of oil, including oil from the Gulf’s numerous natural seeps. There are many natural oil and gas seeps in this part of the Gulf that contribute to a naturally occurring presence of oil components. According to the National Research Council, natural seeps release 560,000 to 1.4 million barrels of oil annually into the Gulf of Mexico. Because they did no chemical analysis, they cannot fingerprint the remnant material to Macondo oil, and also have no information on the toxicity of it. Further, only 3 of their 62 sediment samples had evidence of excess petrocarbon when compared to pre-spill sediment samples.
The oil giant also explained that research released in the Operational Science Advisory Team Report (OSAT-1) back in December 2010 showed that 99 percent of sediment samples remained below aquatic life benchmarks set by the Environmental Protection Agency. OSAT-1 was produced collaboratively by seven federal agencies and BP, while the U.S. Coast Guard led the way. According to BP, this new study pales in comparison to OSAT-1.
One key factor in BP’s response is the area sampled. Data from OSAT-1 showed that sediment samples taken within a 1.86 mile radius of the Macondo wellhead matched the chemical make-up of Macondo oil. Samples outside that circle were inconsistent with the crude which blighted the Gulf. Florida State’s sample area, on the other hand, spanned 9,266 square miles.
BP also refutes the fact that the study held to the belief that 4.8 million barrels of crude were spilled during the 87-day calamity. With a disaster so sizeable, it is difficult to determine exact numbers. BP estimated that about 2.4 million barrels were released, while the scientific community holds to its much higher estimates of up to 4.6 million barrels. For the purposes of determining the final fine amount under the Clean Water Act, U.S. District Judge Carl Barbier ruled on January 15 that 3.19 barrels were discharged into the Gulf, ultimately splitting the difference.
Although BP wholeheartedly contests the findings from the Florida State University, biases must be taken into account. According to the Washington Post, Florida State’s research was funded with money specifically allocated by BP for studying the aftermath of the Gulf spill. If the new research is verified, it could sway Judge Barbier’s decision expected in April regarding how much the company should be fined per barrel.
The scientific community is standing behind the study. IFLScience reports that as the study progressed, researchers specifically avoided areas with natural oil seeps, the same areas BP states has caused the scientists to misconstrue the data. According to the Woods Hole Oceanographic Institution, it is possible for oil from the seabed to collect in the sediment over hundreds of thousands of years. However, recent technological advances have allowed scientists to better detect and estimate those natural oil seeps.
The scientists behind the study used carbon-14 as their tracer, IFLScience explains. Crude oil does not contain carbon-14, a radioactive isotope found in organic materials, because the process of decay over thousands of years has eliminated the isotope. Therefore, any samples which did not contain carbon-14 became the focus of the study’s research.
Because the process of a natural oil seep is incredibly slow, organisms in the area adapt to the change in environment. Those slowly released hydrocarbons have even become an energy source for particular species. Microorganisms also eat away at the chemical structure of the oil—the process more commonly referred to as biodegradation—as it moves through the seafloor. It is possible for biodegraded hydrocarbons to contain carbon-14. If the scientists did sample areas which were part of a natural oil seep, it may have contained carbon-14 and therefore would have been excluded from the study.