A mesocosm experiment to determine half-lives of individual hydrocarbons in simulated oil spill scenarios with and without the dispersant, Corexit

Shi, Dawei; Bera, Gopal; Knap, Anthony H.; Quigg, Antonietta; Atwah, Ibrahim; Gold-Bouchot, Gerardo; Wade, Terry L.

doi:10.1016/j.marpolbul.2019.110804

Cited by 13 publications

(19 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This allows us to evaluate the dispersant’s effects on the microaggregates and microbial communities without the confounding influence of variable oil concentrations between treatments. Over the next 8 days, a decrease in the concentration following first-order decay kinetics occurred after which the concentrations remained stable between 0.25 and 0.45 mg/liter for the duration of the experiment (16 days [ 24 ]). The decreasing ratios of n -C 17 /pristane and n -C 18 /phytane over time indicated that a portion of this loss was attributable to biodegradation (see Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Bacteria-Oil Microaggregates Are an Important Mechanism for Hydrocarbon Degradation in the Marine Water Column

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

“…The decreasing ratios of n -C 17 /pristane and n -C 18 /phytane over time indicated that a portion of this loss was attributable to biodegradation (see Fig. S1 in the supplemental material) ( 24 ). A low but detectable background of hydrocarbons was measured in the seawater control samples that showed no significant change with time ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Bacteria-Oil Microaggregates Are an Important Mechanism for Hydrocarbon Degradation in the Marine Water Column

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The changing fingerprints of aliphatic and aromatic hydrocarbons documented preferential loss on n-alkanes (Morales-McDevitt et al, 2020) and lower molecular weight PAH (Shi et al, 2020) in mesocosm studies further indicating that biodegradation occurred within the first 24 h. In a recent mesocosm experiment designed to measure the rate of loss of n-alkanes over the time period of several days by GC × GC mass spectrometry found that the concentrations of nC 17 and nC 18 alkanes in extracts of MOS decreased with half-lives of 0.9 and 1.0 days, respectively. Such a rapid diminution of alkanes is remarkable but indicative of extremely rapid biodegradation of oil that becomes dispersed within the MOS and enhanced by the presence of Corexit that serves to finely disperse the oil within the MOS (Hatcher, pers.…”

Section: How Does the Presence Of The Resulting Ternary System (Oil-dispersant-eps) Modify The Fate Of The Oil?mentioning

confidence: 99%

Aggregation and Degradation of Dispersants and Oil by Microbial Exopolymers (ADDOMEx): Toward a Synthesis of Processes and Pathways of Marine Oil Snow Formation in Determining the Fate of Hydrocarbons

Quigg

Santschi

et al. 2021

Front. Mar. Sci.

Self Cite

View full text Add to dashboard Cite

Microbes (bacteria, phytoplankton) in the ocean are responsible for the copious production of exopolymeric substances (EPS) that include transparent exopolymeric particles. These materials act as a matrix to form marine snow. After the Deepwater Horizon oil spill, marine oil snow (MOS) formed in massive quantities and influenced the fate and transport of oil in the ocean. The processes and pathways of MOS formation require further elucidation to be better understood, in particular we need to better understand how dispersants affect aggregation and degradation of oil. Toward that end, recent work has characterized EPS as a function of microbial community and environmental conditions. We present a conceptual model that incorporates recent findings in our understanding of the driving forces of MOS sedimentation and flocculent accumulation (MOSSFA) including factors that influence the scavenging of oil into MOS and the routes that promote decomposition of the oil post MOS formation. In particular, the model incorporates advances in our understanding of processes that control interactions between oil, dispersant, and EPS in producing either MOS that can sink or dispersed gels promoting microbial degradation of oil compounds. A critical element is the role of protein to carbohydrate ratios (P/C ratios) of EPS in the aggregation process of colloid and particle formation. The P/C ratio of EPS provides a chemical basis for the “stickiness” factor that is used in analytical or numerical simulations of the aggregation process. This factor also provides a relative measure for the strength of attachment of EPS to particle surfaces. Results from recent laboratory experiments demonstrate (i) the rapid formation of microbial assemblages, including their EPS, on oil droplets that is enhanced in the presence of Corexit-dispersed oil, and (ii) the subsequent rapid oil oxidation and microbial degradation in water. These findings, combined with the conceptual model, further improve our understanding of the fate of the sinking MOS (e.g., subsequent sedimentation and preservation/degradation) and expand our ability to predict the behavior and transport of spilled oil in the ocean, and the potential effects of Corexit application, specifically with respect to MOS processes (i.e., formation, fate, and half-lives) and Marine Oil Snow Sedimentation and Flocculent Accumulation.

show abstract

“…Prior to PAH extraction, each sample was spiked with 50 μL of internal standards (d8-naphthalene, d10-acenaphthene, d10-phenanthrene, d12-chrysene and d12-perylene). SSW samples (700 mL) and AGG samples (5 mL) were extracted with DCM and analyzed with GC/MS as described previously [ 52 , 53 ]. The concentrations of oil used in this study were well below the 200 mg L -1 limit to simulate authentic spill conditions, as this has been a critique among some recent oil toxicity work [ 50 ].…”

Section: Methodsmentioning

confidence: 99%

Diatom aggregation when exposed to crude oil and chemical dispersant: Potential impacts of ocean acidification

et al. 2020

Self Cite

View full text Add to dashboard Cite

Diatoms play a key role in the marine carbon cycle with their high primary productivity and release of exudates such as extracellular polymeric substances (EPS) and transparent exopolymeric particles (TEP). These exudates contribute to aggregates (marine snow) that rapidly transport organic material to the seafloor, potentially capturing contaminants like petroleum components. Ocean acidification (OA) impacts marine organisms, especially those that utilize inorganic carbon for photosynthesis and EPS production. Here we investigated the response of the diatom Thalassiosira pseudonana grown to present day and future ocean conditions in the presence of a water accommodated fraction (WAF and OAWAF) of oil and a diluted chemically enhanced WAF (DCEWAF and OADCEWAF). T . pseudonana responded to WAF/DCEWAF but not OA and no multiplicative effect of the two factors (i.e., OA and oil/dispersant) was observed. T . pseudonana released more colloidal EPS (< 0.7 μm to > 3 kDa) in the presence of WAF/DCEWAF/OAWAF/OADCEWAF than in the corresponding Controls. Colloidal EPS and particulate EPS in the oil/dispersant treatments have higher protein-to-carbohydrate ratios than those in the control treatments, and thus are likely stickier and have a greater potential to form aggregates of marine oil snow. More TEP was produced in response to WAF than in Controls; OA did not influence its production. Polyaromatic hydrocarbon (PAH) concentrations and distributions were significantly impacted by the presence of dispersants but not OA. PAHs especially Phenanthrenes, Anthracenes, Chrysenes, Fluorenes, Fluoranthenes, Pyrenes, Dibenzothiophenes and 1-Methylphenanthrene show major variations in the aggregate and surrounding seawater fraction of oil and oil plus dispersant treatments. Studies like this add to the current knowledge of the combined effects of aggregation, marine snow formation, and the potential impacts of oil spills under ocean acidification scenarios.

show abstract

A mesocosm experiment to determine half-lives of individual hydrocarbons in simulated oil spill scenarios with and without the dispersant, Corexit

Cited by 13 publications

References 43 publications

Bacteria-Oil Microaggregates Are an Important Mechanism for Hydrocarbon Degradation in the Marine Water Column

Bacteria-Oil Microaggregates Are an Important Mechanism for Hydrocarbon Degradation in the Marine Water Column

Aggregation and Degradation of Dispersants and Oil by Microbial Exopolymers (ADDOMEx): Toward a Synthesis of Processes and Pathways of Marine Oil Snow Formation in Determining the Fate of Hydrocarbons

Diatom aggregation when exposed to crude oil and chemical dispersant: Potential impacts of ocean acidification

Contact Info

Product

Resources

About