A report released Aug. 16 by the Georgia Sea Grant and UGA concludes that up to 79 percent of the oil released into the Gulf of Mexico from the Deepwater Horizon well has not been recovered and remains a threat to the ecosystem.
The report, available online at http://uga.edu/aboutUGA/joye_pkit/GeorgiaSeaGrant_OilSpillReport8-16.pdf, strongly contradicts media reports that suggest that only 25 percent of the oil from the Deepwater Horizon oil spill remains.
“One major misconception is that oil that has dissolved into water is gone and, therefore, harmless,” said Charles Hopkinson, director of Georgia Sea Grant and professor of marine sciences in UGA’s Franklin College of Arts and Sciences. “The oil is still out there, and it will likely take years to completely degrade. We are still far from a complete understanding of what its impacts are.”
Co-authors on the paper include Jay Brandes, associate professor, Skidaway Institute of Oceanography; Samantha Joye, professor of marine sciences, UGA; Richard Lee, professor emeritus, Skidaway; and Ming-yi Sun, professor of marine sciences, UGA.
The group analyzed data from the Aug. 2 National Incident Command Report, which calculated an “oil budget” that was widely interpreted to suggest that only 25 percent of the oil from the spill remained.
Hopkinson notes that the reports arrive at different conclusions largely because the Sea Grant and UGA scientists estimate that the vast majority of the oil classified as dispersed, dissolved or residual is still present, whereas the NIC report has been interpreted to suggest that only the “residual” form of oil is still present.
Hopkinson said that his group also estimated how much of the oil could have evaporated, degraded or weathered as of the date of the report. Using a range of reasonable evaporation and degradation estimates, the group calculated that 70-79 percent of oil spilled into the Gulf still remains. The group showed that it was impossible for all the dissolved oil to have evaporated because only oil at the surface of the ocean can evaporate into the atmosphere and large plumes of oil are trapped in deep water.