Tracing the incorporation of carbon into benthic foraminiferal calcite following the Deepwater Horizon event. (June 2018)

• Record Type: Journal Article
• Authors: Schwing, Patrick T.; Chanton, Jeffrey P.; Romero, Isabel C.; Hollander, David J.; Goddard, Ethan A.; Brooks, Gregg R.; Larson, Rebekka A.
• Is Part Of: Environmental pollution. Volume 237(2018)
• Page Start: 424
• Page End: 429
• Publication Date: 2018-06
• Subjects: Benthic foraminifera -- Stable isotopes -- Petroleum -- Gulf of Mexico -- Deepwater Horizon -- MOSSFA; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2018.02.066
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Following the Deepwater Horizon (DWH) event in 2010, hydrocarbons were deposited on the continental slope in the northeastern Gulf of Mexico through marine oil snow sedimentation and flocculent accumulation (MOSSFA). The objective of this study was to test the hypothesis that benthic foraminiferal δ 13 C would record this depositional event. From December 2010 to August 2014, a time-series of sediment cores was collected at two impacted sites and one control site in the northeastern Gulf of Mexico. Short-lived radioisotopes ( 210 Pb and 234 Th) were employed to establish the pre-DWH, DWH, and post-DWH intervals. Benthic foraminifera ( Cibicidoides spp. and Uvigerina spp.) were isolated from these intervals for δ 13 C measurement. A modest (0.2–0.4‰), but persistent δ 13 C depletion in the DWH intervals of impacted sites was observed over a two-year period. This difference was significantly beyond the pre-DWH (background) variability and demonstrated that benthic foraminiferal calcite recorded the depositional event. The longevity of the depletion in the δ 13 C record suggested that benthic foraminifera may have recorded the change in organic matter caused by MOSSFA from 2010 to 2012. These findings have implications for assessing the subsurface spatial distribution of the DWH MOSSFA event. Graphical abstract: Image 1 Highlights: Deepwater Horizon caused modest, persistent depletion in benthic foraminifera δ 13 C. Depletion likely caused by increased carbon flux associated with MOSSFA processes. Benthic foraminifera isotopic composition is robust, persistent recorder of MOSSFA. Abstract : The Deepwater Horizon Event caused a δ 13 C depletion in benthic foraminiferal calcite.