TY - JOUR
T1 - Rapid Degradation of Oil in Mesocosm Simulations of Marine Oil Snow Events
AU - Wozniak, Andrew S.
AU - Prem, Priscilla M.
AU - Obeid, Wassim
AU - Waggoner, Derek C.
AU - Quigg, Antonietta
AU - Xu, Chen
AU - Santschi, Peter H.
AU - Schwehr, Kathleen A.
AU - Hatcher, Patrick G.
N1 - Funding Information:
This research was supported by a grant from The Gulf of Mexico Research Initiative to support consortium research entitled ADDOMEx (Aggregation and Degradation of Dispersants and Oil by Microbial Exopolymers) Consortium, especially Terry Wade, Tony Knap, Luni Sun, Shawn Doyle, and Jason Sylvan. The original data can be found at the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (doi: 10.7266/N7BR8Q8D, doi:10.7266/N7GH9G1K. The authors thank the ADDOMEx team for assistance with mesocosm experiments and data discussions and the ODU COSMIC facility for assistance with FTICR MS analyses.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/4/2
Y1 - 2019/4/2
N2 - Following the Deepwater Horizon oil spill in the Gulf of Mexico, natural marine snow interacted with oil and dispersants forming marine oil snow (MOS) that sank from the water column to sediments. Mesocosm simulations demonstrate that Macondo surrogate oil incorporates into MOS and can be isolated, extracted, and analyzed via Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Up to 47% of the FTICR-MS signal from MOS extracts can be attributed to formulas also found in Macondo surrogate oil demonstrating extensive oil incorporation. Additionally, oxygenation patterns for MOS extracts provide evidence for degraded oil compounds. Formulas having similar double bond equivalents but higher oxygen content (MOS CHO: CHO 2-9 , DBE 2-16 , MOS CHON: CHO 0-7 N 1 , DBE 9-18; Macondo CHO: CHO 1-4 , DBE 2-15 , CHON: CHO 0-3 N 1 , DBE 9-21 ) were found in MOS extracts generating isoabundance distributions similar to those of environmentally aged oil. Such shifts in molecular composition are consistent with the transformation of high DBE oil components, unobservable by FTICR-MS until oxygenation in the mesocosms. Low light conditions and the rapid proliferation of hydrocarbon-degraders observed in parallel studies suggest biological activity as the primary cause of oil degradation. MOS may thus represent an important microenvironment for oil degradation especially during its long transit below the euphotic zone to sediments.
AB - Following the Deepwater Horizon oil spill in the Gulf of Mexico, natural marine snow interacted with oil and dispersants forming marine oil snow (MOS) that sank from the water column to sediments. Mesocosm simulations demonstrate that Macondo surrogate oil incorporates into MOS and can be isolated, extracted, and analyzed via Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Up to 47% of the FTICR-MS signal from MOS extracts can be attributed to formulas also found in Macondo surrogate oil demonstrating extensive oil incorporation. Additionally, oxygenation patterns for MOS extracts provide evidence for degraded oil compounds. Formulas having similar double bond equivalents but higher oxygen content (MOS CHO: CHO 2-9 , DBE 2-16 , MOS CHON: CHO 0-7 N 1 , DBE 9-18; Macondo CHO: CHO 1-4 , DBE 2-15 , CHON: CHO 0-3 N 1 , DBE 9-21 ) were found in MOS extracts generating isoabundance distributions similar to those of environmentally aged oil. Such shifts in molecular composition are consistent with the transformation of high DBE oil components, unobservable by FTICR-MS until oxygenation in the mesocosms. Low light conditions and the rapid proliferation of hydrocarbon-degraders observed in parallel studies suggest biological activity as the primary cause of oil degradation. MOS may thus represent an important microenvironment for oil degradation especially during its long transit below the euphotic zone to sediments.
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U2 - 10.1021/acs.est.8b06532
DO - 10.1021/acs.est.8b06532
M3 - Article
C2 - 30827089
AN - SCOPUS:85063909306
SN - 0013-936X
VL - 53
SP - 3441
EP - 3450
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 7
ER -