Deepwater Horizon Event Research Articles

NIEHS Oil Spill Health and Safety Training: Learning from Deepwater Horizon to Improve Future Response Training

ABSTRACT: When the Deepwater Horizon oil drilling rig exploded on April 20, 2010, in the Gulf of Mexico, the United States faced an enormous challenge. The massive oil release had significant consequences in the region for the environment and for human health. The U.S. government has plans in place for an emergency response to disasters, and these plans are based on experiences during previous disasters, including the Exxon Valdez oil spill, the World Trade Center (WTC) disaster, and Hurricanes Katrina and Rita. After each disaster, the emergency response was evaluated and analysis of lessons learned led to revised emergency response plans for oil spills and for other types of disasters. In the case of the Deepwater Horizon event, the National Contingency Plan (NCP) was activated. The disaster response was implemented rapidly on a huge scale. Numerous governmental agencies, non-governmental organizations, local groups, and BP employees and contractors were engaged. Over 47,000 cleanup workers were trained to deal with the oil release. (See Table One) Over time, concerns have been raised about the health of cleanup workers, and the monitoring of their health continues.Table One:DWH Workforce Metrics The National Institute of Environmental Health Sciences (NIEHS) Worker Education and Training Program (WETP) held a workshop in Mobile, AL on May 4–5, 2011 that included a broad range of participants who were involved in the Deepwater Horizon response. This paper summarizes findings from the workshop report of what worked and what did not work as the basis for improvements in preparedness for future disasters. Specifically, workshop findings and recommendations focused on two topics: community engagement in the response process and the development of safety training for non-professional cleanup workers. The dialogue revealed that local community resources were utilized during the Deepwater Horizon response. However, workshop attendees noted areas for improving community engagement. They expressed that communities possess unparalleled knowledge of their local environments and can provide a valuable workforce to support response efforts. Workshop participants also called attention to a need to consider local community health issues in the response plan, so that information, appropriate medical care, and other health needs are addressed rapidly. While worker training was implemented quickly, training quality needs improvement. Issues around appropriate pre-incident training need to be addressed by OSHA and others responsible for worker protection. The Deepwater Horizon oil release was a disaster that called upon the U.S. to assemble and deploy tremendous resources to address an evolving challenge. The response was rapid, resilient, and in many ways effective. Workshop participant experience documents areas for improvement. The government has taken experiences from previous disasters to revise national disaster response plans. Deepwater Horizon response, as summarized in this report, can be applied to further improve worker safety and health training so that emergency responses to future disasters can more effectively address the challenges and needs of those involved in the event.

Did the Deepwater Horizon oil spill affect growth of Red Snapper in the Gulf of Mexico?

The explosion of the Deepwater Horizon (DWH) oil platform in 2010 released more than 200 million gallons of crude oil into the northern Gulf of Mexico (GoM). Elevated levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs) were abundant in the upper water column throughout the event. Previous research suggests that PAHs may have negatively affected fishes in the northern GoM. Our objective was to test whether crude oil contamination from the DWH oil spill was correlated with changes in growth rates in adult Red Snapper, Lutjanus campechanus. We fit von Bertalanffy growth curves and back-calculated length-at-age using data collected from 2011–2013 during long-line surveys in the northern GoM and on the West Florida Shelf. No significant variation in von Bertalanffy growth parameters existed among the catch years; a combined-years model gave L∞, k, and t0 values of 82.91, 0.20, and 0.43, respectively. No significant difference existed between pre- (back-calculated) and post-DWH growth curves. However, annual widths of the fourth, fifth, and sixth increments (the dominant cohorts in the population) declined significantly post-DWH (2010–2012) by 13%, 15%, and 22%, respectively, and were significantly smaller than the mean width of each respective increment in pre-spill years (2006–2009). While the DWH event was related temporally to growth declines in the dominant adult age groups, other environmental factors (winds, temperature, and river discharge) may also affect growth. Accordingly, meridional (V) and zonal (U) winds, sea level height anomalies (a proxy for water temperature variation), and Mississippi River discharge were compared to increment widths but none of the factors were strongly correlated with variation in age-specific growth increments (maximum Pearson’s r=0.47). Therefore, we are unable to reject the hypothesis that the DWH resulted in growth rate declines as opposed to climatic variation.

Characterizing the variability of benthic foraminifera in the northeastern Gulf of Mexico following the Deepwater Horizon event (2010-2012).

Following the Deepwater Horizon (DWH) event in 2010 subsurface hydrocarbon intrusions (1000-1300m) and an order of magnitude increase in flocculent hydrocarbon deposition caused increased concentrations of hydrocarbons in continental slope sediments. This study sought to characterize the variability [density, Fisher's alpha (S), equitability (E), Shannon (H)] of benthic foraminifera following the DWH event. A series of sediment cores were collected at two sites in the northeastern Gulf of Mexico from 2010 to 2012. At each site, three cores were utilized for benthic faunal analysis, organic geochemistry, and redox metal chemistry, respectively. The surface intervals (∼0-10mm) of the sedimentary records collected in December 2010 at DSH08 and February 2011 at PCB06 were characterized by significant decreases in foraminiferal density, S, E, and H, relative to the down-core intervals as well as previous surveys. Non-metric multidimensional scaling (nMDS) analysis suggested that a 3-fold increase in polycyclic aromatic hydrocarbon (PAH) concentration in the surface interval, relative to the down-core interval, was the environmental driver of benthic foraminiferal variability. These records suggested that the benthic foraminiferal recovery time, following an event such as the DWH, was on the order of 1-2years.

Effect of Macondo Prospect 252 Oil on Microbiota Associated with Pelagic Sargassum in the Northern Gulf of Mexico.

The environmental impact of major oil spills on marine microorganisms has yet to be thoroughly investigated using molecular biology techniques. The Deepwater Horizon (DWH) drilling rig explosion of 2010 affected an approximately 176,000km2 surface area of the Gulf of Mexico (GOM) when an estimated 210 million gallons of oil from the Macondo Prospect spilled into the environment. Pelagic Sargassum, a complex of two surface drifting species (Sargassum natans and Sargassum fluitans) of marine brown macroalgae and a critically important habitat in the GOM ecosystem, was suffused by Macondo Prospect 252 oil released during the DWH event. Using 16S rRNA PCR and Roche 454 pyrosequencing, the effect of the oil on the bacterial population associated with pelagic Sargassum and contiguous waters was examined by comparing sequence data generated from samples collected from oiled and non-oiled locations in the northern GOM. Sequence data showed similar microbial composition in Sargassum regardless of exposure to oil primarily dominated by five phyla; Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, and unclassified bacteria. The microbial composition in water samples was significantly less diverse than for Sargassum and consisted primarily of Proteobacteria, Firmicutes, and Bacteroidetes. Due to the evenly distributed abundance of microbial species on oiled and non-oiled pelagic Sargassum, study findings indicate that DWH spilled oil had minimal effect on the composition and diversity of the microbial community associated with Sargassum and contiguous waters. However, higher abundances of Sulfitobacter and one species of Psychrobacter were found in oiled water samples when compared to non-oiled water samples indicating some effect of DHW oil in the microbial composition of seawater. Though there are a number of marine studies using molecular biology approaches, this is the first molecular examination of the impact of the DWH oil spill on bacterial communities associated with pelagic Sargassum and contiguous waters from the GOM.

Modeling the influence of deep water application of dispersants on the surface expression of oil: A sensitivity study

AbstractAlthough the effects of chemical dispersants on oil droplet sizes and ascent speeds are well‐known, the fate and transport of dispersed oil droplets of different sizes under varying hydrodynamic conditions can be difficult to assess with observations alone. We used a particle tracking model to evaluate the effect of changes in droplet sizes due to dispersant application on the short‐term transport and surface expression of oil released under conditions similar to those following the 3 June 2010 riser cutting during the Deepwater Horizon event. We used simulated injections of oil droplets of varying size and number under conditions associated with no dispersant application and with dispersant application at 50% and 100% efficiency. Due to larger droplet sizes in the no‐dispersant scenario, all of the simulated oil reached the surface within 7 h, while only 61% and 28% of the oil reached the surface after 12 h in the 50% and 100% dispersant efficiency cases, respectively. The length of the surface slick after 6 h was ∼2 km in the no‐dispersant case whereas there was no surface slick after 6 h in the 100% dispersant case, because the smaller oil droplets which resulted from dispersant application had not yet reached the surface. Model results suggest that the application of dispersants at the well head had the following effects: (1) less oil reached the surface in the 6‐12 h after application, (2) oil had a longer residence time in the water‐column, and (3) oil was more highly influenced by subsurface transport.

Characterization of surface oil thickness distribution patterns observed during the Deepwater Horizon (MC-252) oil spill with aerial and satellite remote sensing

Knowledge of the spatial distribution of oil thickness patterns within an on-water spill is of obvious importance for immediate spill response activities as well as for subsequent evaluation of the spill impacts. For long-lasting continuous spills like the 2010 3-month Deepwater Horizon (DWH) event in the Gulf of Mexico, it is also important to identify changes in the dominant oil features through time. This study utilized very high resolution (≤5m) aerial and satellite imagery acquired during the DWH spill to evaluate the shape, size and thickness of surface oil features that dominated the DWH slick. Results indicate that outside of the immediate spill source region, oil distributions did not encompass a broad, varied range of thicknesses. Instead, the oil separated into four primary, distinct characterizations: 1) invisible surface films detectable only with Synthetic Aperture Radar imaging because of the decreased surface backscatter, 2) thicker sheen & rainbow areas (<0.005mm), 3) large regional areas of relatively thin, “metallic appearance” films (0.005–0.08mm), and 4) strands of thick, emulsified oil (>1mm) that were consistently hundreds of meters long but most commonly only 10–50m wide. Where present within the slick footprint, each of the three distinct visible oil thickness classes maintained its shape characteristics both spatially (at different distances from the source and in different portions of the slick), and temporally (from mid-May through July 2010). The region over the source site tended to contain a more continuous range of oil thicknesses, however, our results indicate that the continuous injection of subsurface dispersants starting in late May significantly altered (lowered) that range. In addition to characterizing the oil thickness distribution patterns through the timeline of one of the world's largest oil spills, this paper also details the extension of using high resolution aerial imagery to calibrate medium resolution satellite data sources such as USA's Thematic Mapper (30m) to provide larger-scale spatial views of major spills, and discusses implications for utilizing such data for oil spill characterizations and spill response.

Persistent impacts to the deep soft-bottom benthos one year after the Deepwater Horizon event.

In fall 2010, several months after the Deepwater Horizon blowout was capped, zones of moderate and severe impacts to deep-sea, soft-bottom benthos were identified that together extended over an area of 172 km2 . A subset of stations sampled in 2010 was resampled in May and June 2011, 10 to 11 months after the event, to determine whether the identified adverse effects were persisting. The design compared 20 stations from the combined moderate and severe impact zone to 12 stations in the reference zone that were sampled in both years. There were no statistically significant differences in contaminant concentrations between the impact and nonimpact zones from 2010 to 2011, which indicates contaminants persisted after 1 y. Whereas there were some signs of recovery in 2011 (particularly for the meiofauna abundance and diversity), there was evidence of persistent, statistically significant impacts to both macrofauna and meiofauna community structure. Macrofaunal taxa richness and diversity in 2011 were still 22.8% and 35.9% less, respectively, in the entire impact zone than in the surrounding nonimpact area, and meiofaunal richness was 28.5% less in the entire impact zone than in the surrounding area. The persistence of significant biodiversity losses and community structure change nearly 1 y after the wellhead was capped indicates that full recovery had yet to have occurred in 2011. Integr Environ Assess Manag 2017;13:342-351. © 2016 SETAC.

Molecular characterization of benthic foraminifera communities from the Northeastern Gulf of Mexico shelf and slope following the Deepwater Horizon event

Benthic foraminifera are globally distributed protozoa in the world's oceans, which have been used as ecological indicators in both current and palaeo oceanography. The ecological properties and distribution of these organisms in various regions of the Gulf of Mexico (GOM) have been evaluated using microscopy; however molecular approaches for these purposes have been limited, especially in deeper regions. The BP Deepwater Horizon oil well failure in the northern Gulf of Mexico highlighted the need to better understand the distribution and abundance of these organisms relative to environmental factors and ecosystem perturbations such as the oil spill. Sediment samples were collected using a Shipek grab along transects on the northwest Florida GOM shelf (18–270m depth). Clone libraries were developed from PCR amplified 18S rDNA genes for sequence analysis. Analysis of random clones from libraries were used as a proxy for community structure (presence and relative abundance) to document the spatial and temporal dynamics of benthic foraminifera on the Northwest Florida Shelf in the NE GOM shelf. Additional continental slope samples (200–1600m depth) were obtained by a multicorer and treated in similar fashion. Mean species diversity in this study (H=2.49–3.36), agreed with pre-DWH event estimates, however the dominant agglutinated species in the deep-water samples did not match previous studies. Additionally, the dominant calcareous taxa from this study such as Allogromida sp. and Psammophaga sp., were inconsistent with previous reports. The dominant taxa in both coastal and deep-water sites include Glabratellina sp., Trochammina hadai, and Trochammina sp., and Textularia sagittula and Bathysiphon argenteus as well as members of genera Astrammina, Bolivina, Cibicides and Cibicidoides.

Surface dynamics of crude and weathered oil in the presence of dispersants: Laboratory experiment and numerical simulation

AbstractMarine oil spills can have dire consequences for the environment. Research on their dynamics is important for the well‐being of coastal communities and their economies. Propagation of oil spills is a very complex physical‐chemical process. As seen during the Deepwater Horizon event in the Gulf of Mexico during 2010, one of the critical problems remaining for prediction of oil transport and dispersion in the marine environment is the small‐scale structure and dynamics of surface oil spills. The laboratory experiments conducted in this work were focused on understanding the differences between the dynamics of crude and weathered oil spills and the effect of dispersants. After deposition on the still water surface, a drop of crude oil quickly spread into a thin slick; while at the same time, a drop of machine (proxy for weathered) oil did not show significant evolution. Subsequent application of dispersant to the crude oil slick resulted in a quick contraction or fragmentation of the slick into narrow wedges and tiny drops. Notably, the slick of machine oil did not show significant change in size or topology after spraying dispersant. An advanced multi‐phase, volume of fluid computational fluid dynamics model, incorporating capillary forces, was able to explain some of the features observed in the laboratory experiment. As a result of the laboratory and modeling experiments, the new interpretation of the effect of dispersant on the oil dispersion process including capillary effects has been proposed, which is expected to lead to improved oil spill models and response strategies.

Effects of Exposure of Pink Shrimp, Farfantepenaeus duorarum, Larvae to Macondo Canyon 252 Crude Oil and the Corexit Dispersant

The release of oil into the Gulf of Mexico (GOM) during the Deepwater Horizon event coincided with the white and pink shrimp spawning season. To determine the potential impact on shrimp larvae a series of static acute (24–96 h) toxicity studies with water accommodated fractions (WAFs) of Macondo Canyon (MC) 252 crude oil, the Corexit 9500A dispersant, and chemically enhanced WAFS (CEWAFs) were conducted with nauplii, zoea, mysid, and postlarval Farfantepenaeus duorarum. Median lethal concentrations (LC50) were calculated and behavior responses (swimming, molting, light sensitivity) evaluated. Impacts were life stage dependent with zoea being the most sensitive. Behavioral responses for all stages, except postlarvae, occurred at below LC50 values. Dispersants had the greatest negative impact while WAFs had the least. No short-term effects (survival, growth) were noted for nauplii exposed to sub-lethal CEWAFs 39 days post-exposure. This study points to the importance of evaluating multiple life stages to assess population effects following contaminant exposure and further, that the use of dispersants as a method of oil removal increases oil toxicity.

Reliability seeking virtual organizations: Challenges for high reliability organizations and resilience engineering

High reliability organizing is an important approach to crisis prevention and mitigation. Resilience is a term that has been used to describe an organization’s ability to respond or ‘bounce back’ from untoward, surprising or disruptive events. A growing number of organizations have increased mandates for maintaining safety, reliability and resilience; some of these are also virtual or semi virtual organizations—geographically distributed organizations whose members are bound by a long-term common interest or goal, and who largely communicate and coordinate their work through information technology. The objective of this paper is to explicate the challenges that reliability-seeking virtual organizations (RSVOs) pose for high reliability and resilient organizations, based on what is known about high reliability organizations (HROs) and resilient organizations, and what can be surmised about RSVOs. We begin by exploring a test case for RSVOs, distributed offshore oil and gas systems, using the example of the challenges presented during the Deepwater Horizon event. Since a common characteristic of resilient and reliable organizations is fluidity in organizational structures, we examine requirements for fluidity in and across RSVO organizational structures and the forms that fluidity can assume, leaning on our understanding of the role of fluidity in HROs and resilient organizations, and suggesting challenges posed by these different forms of interconnectedness. We then follow with a discussion of when a virtual organization is not highly reliable or resilient. We describe future RSVO challenges in remote settings with little infrastructure, such as Arctic energy exploration and development and IT-enabled healthcare systems in third world countries, and conclude with an agenda for future research.

Hydrocarbons in Deep-Sea Sediments following the 2010 Deepwater Horizon Blowout in the Northeast Gulf of Mexico

The Deepwater Horizon (DWH) spill released 4.9 million barrels of oil into the Gulf of Mexico (GoM) over 87 days. Sediment and water sampling efforts were concentrated SW of the DWH and in coastal areas. Here we present geochemistry data from sediment cores collected in the aftermath of the DWH event from 1000 – 1500 m water depth in the DeSoto Canyon, NE of the DWH wellhead. Cores were analyzed at high-resolution (at 2 mm and 5 mm intervals) in order to evaluate the concentration, composition and input of hydrocarbons to the seafloor. Specifically, we analyzed total organic carbon (TOC), aliphatic, polycyclic aromatic hydrocarbon (PAHs), and biomarker (hopanes, steranes, diasteranes) compounds to elucidate possible sources and transport pathways for deposition of hydrocarbons. Results showed higher hydrocarbon concentrations during 2010-2011 compared to years prior to 2010. Hydrocarbon inputs in 2010-2011 were composed of a mixture of sources including terrestrial, planktonic, and weathered oil. Our results suggest that after the DWH event, both soluble and highly insoluble hydrocarbons were deposited at enhanced rates in the deep-sea. We proposed two distinct transport pathways of hydrocarbon deposition: 1) sinking of oil-particle aggregates (hydrocarbon-contaminated marine snow and/or suspended particulate material), and 2) advective transport and direct contact of the deep plume with the continental slope surface sediments between 1000-1200 m. Our findings underline the complexity of the depositional event observed in the aftermath of the DWH event in terms of multiple sources, variable concentrations, and spatial (depth-related) variability in the DeSoto Canyon, NE of the DWH wellhead.

A decline in benthic foraminifera following the deepwater horizon event in the northeastern Gulf of Mexico.

Sediment cores were collected from three sites (1000–1200 m water depth) in the northeastern Gulf of Mexico from December 2010 to June 2011 to assess changes in benthic foraminiferal density related to the Deepwater Horizon (DWH) event (April-July 2010, 1500 m water depth). Short-lived radioisotope geochronologies (210Pb, 234Th), organic geochemical assessments, and redox metal concentrations were determined to relate changes in sediment accumulation rate, contamination, and redox conditions with benthic foraminiferal density. Cores collected in December 2010 indicated a decline in density (80–93%). This decline was characterized by a decrease in benthic foraminiferal density and benthic foraminiferal accumulation rate (BFAR) in the surface 10 mm relative to the down-core mean in all benthic foraminifera, including the dominant genera (Bulimina spp., Uvigerina spp., and Cibicidoides spp.). Cores collected in February 2011 documented a site-specific response. There was evidence of a recovery in the benthic foraminiferal density and BFAR at the site closest to the wellhead (45 NM, NE). However, the site farther afield (60 NM, NE) recorded a continued decline in benthic foraminiferal density and BFAR down to near-zero values. This decline in benthic foraminiferal density occurred simultaneously with abrupt increases in sedimentary accumulation rates, polycyclic aromatic hydrocarbon (PAH) concentrations, and changes in redox conditions. Persistent reducing conditions (as many as 10 months after the event) in the surface of these core records were a possible cause of the decline. Another possible cause was the increase (2–3 times background) in PAH’s, which are known to cause benthic foraminifera mortality and inhibit reproduction. Records of benthic foraminiferal density coupled with short-lived radionuclide geochronology and organic geochemistry were effective in quantifying the benthic response and will continue to be a valuable tool in determining the long-term effects of the DWH event on a larger spatial scale.

Effects of Macondo Canyon 252 Oil (Naturally and Chemically Dispersed) on LarvalCrassostrea virginica(Gmelin, 1791)

ABSTRACT A series of acute and sublethal experiments were conducted to examine the potential effects of exposure to wateraccommodated fractions (WAFs) of Macondo Canyon 252 crude oil and chemically enhanced (Corexit 9500A dispersant) wateraccommodated fractions (CEWAFs) on embryogenesis, larval development, growth, and survival of the eastern oyster, Crassostrea virginica. Nominal exposure concentrations for acute experiments were 0, 100, 200, 400, 800 and 1,200 mg/L for WAFs, and 0, 6.25, 12.5, 25, 50, 100, and 200 mg/L for CEWAFs. Calculated total polycyclic aromatic hydrocarbon (TPAH) values were 0, 22.5, 45, 90, 181, and 271 µg/L for WAFs, and 0, 4.5, 8.9, 17.8, 35.7, 71, and 142 µg/L for CEWAFs. The exposure concentration for sublethal experiments was 16 mg/L CEWAF. Total polycyclic aromatic hydrocarbon concentrations represent moderate to high levels of TPAH reported during the Deepwater Horizon (DWH) event. Exposure to acute concentrations of 1 or both of these contaminants was shown to decrease fe...

Effect of high pressure on hydrocarbon-degrading bacteria.

The blowout of the Deepwater Horizon in the Gulf of Mexico in 2010 occurred at a depth of 1500 m, corresponding to a hydrostatic pressure of 15 MPa. Up to now, knowledge about the impact of high pressure on oil-degrading bacteria has been scarce. To investigate how the biodegradation of crude oil and its components is influenced by high pressures, like those in deep-sea environments, hydrocarbon degradation and growth of two model strains were studied in high-pressure reactors. The alkane-degrading strain Rhodococcus qingshengii TUHH-12 grew well on n-hexadecane at 15 MPa at a rate of 0.16 h−1, although slightly slower than at ambient pressure (0.36 h−1). In contrast, the growth of the aromatic hydrocarbon degrading strain Sphingobium yanoikuyae B1 was highly affected by elevated pressures. Pressures of up to 8.8 MPa had little effect on growth of this strain. However, above this pressure growth decreased and at 12 MPa or more no more growth was observed. Nevertheless, S. yanoikuyae continued to convert naphthalene at pressure >12 MPa, although at a lower rate than at 0.1 MPa. This suggests that certain metabolic functions of this bacterium were inhibited by pressure to a greater extent than the enzymes responsible for naphthalene degradation. These results show that high pressure has a strong influence on the biodegradation of crude oil components and that, contrary to previous assumptions, the role of pressure cannot be discounted when estimating the biodegradation and ultimate fate of deep-sea oil releases such as the Deepwater Horizon event.

An effective dispersant for oil spills based on food-grade amphiphiles.

Synthetic dispersants such as Corexit 9500A were used in large quantities (∼2 million gallons) to disperse the oil spilled in the ocean during the recent Deepwater Horizon event. These dispersant formulations contain a blend of surfactants in a base of organic solvent. Some concerns have been raised regarding the aquatic toxicity and environmental impact of these formulations. In an effort to create a safer dispersant, we have examined the ability of food-grade amphiphiles to disperse (emulsify) crude oil in seawater. Our studies show that an effective emulsifier is obtained by combining two such amphiphiles: lecithin (L), a phospholipid extracted from soybeans, and Tween 80 (T), a surfactant used in many food products including ice cream. Interestingly, we find that L/T blends show a synergistic effect, i.e., their combination is an effective emulsifier, but neither L or T is effective on its own. This synergy is maximized at a 60/40 weight ratio of L/T and is attributed to the following reasons: (i) L and T pack closely at the oil-water interface; (ii) L has a low tendency to desorb, which fortifies the interfacial film; and (iii) the large headgroup of T provides steric repulsions between the oil droplets and prevents their coalescence. A comparison of L/T with Corexit 9500A shows that the former leads to smaller oil droplets that remain stable to coalescence for a much longer time. The smaller size and stability of crude oil droplets are believed to be important to their dispersion and eventual microbial degradation in the ocean. Our findings suggest that L/T blends could potentially be a viable alternative for the dispersion of oil spills.

Characterization of the BP petroleum residuals in the sediment of the Salt Marshes in the Northern Gulf of Mexico by Fourier Transform Ion Cyclotron Resonance mass spectrometry

Of the estimated 5 million barrels of crude oil released into the Gulf of Mexico from the BP Deepwater Horizon event, a fraction heavily oiled Louisiana's coastal salt marshes. Oil inputs may significantly alter the abundance, structure and diversity of the microbial communities inhabited in the sediments, and subsequently affect essential microbial services. In this study, detailed analysis was conducted to investigate the possible impact of petroleum residuals on soil microbial communities of salt marsh in northern Barataria Bay of the Gulf of Mexico after the oil spill. Sediment samples from heavily, moderately, non-oiled sites were collected after 7 months, 16 months and 29 months of the spill and Total Petroleum Hydrocarbons (TPH) were measured. Since traditional gas chromatography (GC) analysis cannot identify heavy fractions of the oil containments, we incorporated ultrahigh resolving power Fourier Transform Ion Cyclotron Resonance mass spectrometry (FT-ICR-MS) to address the compositional complexity of high molecular weight, nonvolatile petroleum fractions of the oil containments that are not readily degraded by the indigenous microbial community. The petrogentic material was extracted with methylene chloride followed by positive and negative electrospray (ESI) FT-ICR-MS characterization. These data can be correlated with the analysis of the diversity and structure of the microbial community to elucidate how the oil contamination perturbed the microbial community and how the microbes responded to the perturbation. Mass spectrometry analysis of these samples display a 1.5 to 2.5 fold increase in the molecular complexity, particularly oxygen compounds relative to the original Macondo well oil and ketone species were abundantly present in the oiled sediment extracts. The comprehensive analysis on the petroleum residues will help us better understand the fate of oil released into the environment and the long-term impact of BP oil spill.

Fossil Carbon in Particulate Organic Matter in the Gulf of Mexico following the Deepwater Horizon Event

In 2010, the Deepwater Horizon event released large quantities of natural gas into the Gulf of Mexico in addition to oil. Several studies have reported evidence of the introduction of petro-based carbon into the Gulf planktonic foodweb. This study reports results consistent with the hypothesis that methane-derived carbon entered the food web through small particles indicative of methanotrophy. Suspended particulate organic carbon (POCsusp), collected from the Gulf water column in 2011 and 2012, was depleted of δ13C and Δ14C relative to surface planktonic production. The suspended particulate organic fraction was as depleted as −37‰ in δ13C and −618‰ in Δ14C. The 13C and 14C values were strongly correlated and indicated the admixture of modern surface carbon with a depleted radiocarbon source that had a δ13C value indicative of methane input. Mixing models indicated that 28–43% of the POCsusp may have been derived from fossil CH4.

An Incomplete Solution: Oil and Water in Louisiana

June 2012 The Journal of American History 91 A series of major calamities in recent years has placed the national spotlight on the lower Mississippi River industrial complex—a sinuous arrangement of petrochemical plants and working-class communities set amid the sugarcane fields on the alluvial floodplain. Hurricanes Katrina and Rita damaged offshore oil rigs and onshore refineries in 2005, caused oil releases, and increased gasoline prices, thereby exposing the region’s significant position in the energy economy. The 2010 Deepwater Horizon event showcased the environmental costs of extractive activities; and the near-record Mississippi River flood of 2011 disrupted waterborne commerce and raised the specter of levee failures. As those events displayed, this nationally prominent ensemble of industries occupies a location susceptible to a host of environmental forces and a place where industrial activities have produced dramatic consequences. Testing the environment’s capacity to absorb human impacts has been going on for decades and has left enduring traces on the Louisiana landscape. Erection of petroleum refineries in this region began in the first decade of the twentieth century, during a time of almost nonexistent environmental regulation. Yet, even in the early decades of petrochemical growth, the state, its citizens, and industry acknowledged both human safety risks and environmental threats posed by the arrival of this new enterprise. Industry took the position that self-regulation would minimize personal, property, and environmental harm. Government bodies largely consented to this approach until calamities revealed the accumulating human and environmental costs that had turned the lower Mississippi River corridor into an environmental “sacrifice zone.” That term derives from the study of traditional agricultural practices where cultivators deliberately degraded one area to increase productivity in another area, but scholars have begun using the term in explicitly accusatory ways to refer to areas degraded by modern industrial societies in the pursuit of economic and military gain. Environmental degradation in the lower Mississippi River industrial complex was not the result of a coordinated assault; rather it reflected negligent behavior by industries and government authorities. And significantly, those behaviors defied what contemporary trade literature presented as good industry practice. Sacrifice zone here refers to the result of disconnected actions that over time had An Incomplete Solution: Oil and Water in Louisiana