Fate of dispersants associated with the deepwater horizon oil spill.
Response actions to the Deepwater Horizon oil spill included the injection of ∼771,000 gallons (2,900,000 L) of chemical dispersant into the flow of oil near the seafloor. Prior to this incident, no deepwater applications of dispersant had been conducted, and thus no data exist on the environmental fate of dispersants in deepwater. We used ultrahigh resolution mass spectrometry and liquid chromatography with tandem mass spectrometry (LC/MS/MS) to identify and quantify one key ingredient of the dispersant, the anionic surfactant DOSS (dioctyl sodium sulfosuccinate), in the Gulf of Mexico deepwater during active flow and again after flow had ceased. Here we show that DOSS was sequestered in deepwater hydrocarbon plumes at 1000-1200 m water depth and did not intermingle with surface dispersant applications. Further, its concentration distribution was consistent with conservative transport and dilution at depth and it persisted up to 300 km from the well, 64 days after deepwater dispersant applications ceased. We conclude that DOSS was selectively associated with the oil and gas phases in the deepwater plume, yet underwent negligible, or slow, rates of biodegradation in the affected waters. These results provide important constraints on accurate modeling of the deepwater plume and critical geochemical contexts for future toxicological studies.
Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
Elizabeth B
EB
Kujawinski
Melissa C
MC
Kido Soule
David L
DL
Valentine
Angela K
AK
Boysen
Krista
K
Longnecker
Molly C
MC
Redmond
D001673:Biodegradation, Environmental; D004143:Dioctyl Sulfosuccinic Acid / Q000032:analysis* / Q000378:metabolism; D060851:Gulf of America; D006838:Hydrocarbons / Q000032:analysis; D059392:Petroleum Pollution / Q000032:analysis*; D013501:Surface-Active Agents / Q000032:analysis; D053719:Tandem Mass Spectrometry; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
D006838:Hydrocarbons; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D004143:Dioctyl Sulfosuccinic Acid