Never Waste a Good Crisis: Deepwater Horizon and a Call for Congressional Action

Polychaete annelid (segmented worms) abundance and species composition in the proximity (6–9 km) of the Deep Water Horizon (DWH) Oil Spill in the Deep Gulf of Mexico

Nine years after the Deepwater Horizon (DwH) oil spill (20 April–15 July 2010), the recovery of primary productivity at the ocean surface remains to be investigated. Here, we used the normalized fluorescence line height (nFLH) from the Moderate Resolution Imaging Spectroradiometer as an indicator of chlorophyll a concentration (Chl a). First, from the spatiotemporal variations of nFLH between 2001 and 2017, a reduction of nFLH after the DwH oil spill was observed (for a relatively long period, from 2011 to 2014). Second, a stepwise multiple regression model was used to examine which of the following environmental factors could explain the annual variations in nFLH: river discharge, total nitrogen load, total phosphorus load, photosynthetically available radiation, sea surface temperature and wind speed. Results show that river discharge, sea surface temperature and wind speed are the primary factors that regulated the annual nFLH variations in the DwH area during the pre-spill years. In contrast, this same model could not explain the reduction of nFLH for the four years after the DwH oil spill. After 2015, nFLH appears to have resumed to the pre-spill concentrations. Here we suggest that the nFLH reduction between 2011 and 2014 could have originated from the DwH oil spill, although the exact mechanism is yet to be determined.

The Deepwater Horizon (DWH) oil spill was the first spill that occurred in the deep ocean, nearly one mile below the ocean’s surface. The large-scale applications of dispersants used at the surface and wellhead during the Deepwater Horizon oil spill raised many questions and highlighted the importance of understanding their effects on the marine environment. 
 This 9-page fact sheet concerns the use of dispersants in response to the Deepwater Horizon (DWH) oil spill, the first spill that occurred in the deep ocean, nearly a mile below the surface. Written by Monica Wilson, Larissa Graham, Christine Hale, Emily Maung-Douglass, Stephen Sempier, and LaDon Swann and published by the Florida Sea Grant College Program, the fact sheet was selected for publication on EDIS by Monica Wilson. Originally published at the National Sea Grant Library: https://eos.ucs.uri.edu/EOS_Linked_Documents/gomsg/EX-GOMRI-1%20-%20Wilson_M_2015.pdfhttp://edis.ifas.ufl.edu/sg150

Chemical and histological comparisons between Brevoortia sp. (menhaden) collected in fall 2010 from Barataria Bay, LA and Delaware Bay, NJ following the DeepWater Horizon (DWH) oil spill

Population genomics of Fundulus grandis exposed to oil from Deepwater Horizon

The impact of Deepwater Horizon oil spill on petroleum hydrocarbons in surface waters of the northern Gulf of Mexico

Red Snapper Lutjanus campechanus were sampled at 33 natural and 27 artificial reef sites in the northern Gulf of Mexico prior to (2009–2010) and after (2010–2011) to examine potential diet and trophic shifts following the Deepwater Horizon (DWH) oil spill. We dissected 708 stomachs for gut content analysis and processed 65 muscle tissue samples for stable isotope ratio-mass spectrometry analysis of δ13C, δ15N, and δ34S. Forty-eight percent of stomachs contained identifiable prey, which we grouped into seven categories: fish, decapods, cephalopods, stomatopods, gastropods, zooplankton, and other invertebrates. Based on these categories, Red Snapper diet was significantly different following the DWH oil spill, and was differentially affected by fish size. The interaction between habitat (natural versus artificial reefs) and DWH oil spill effects was also significant. Significant differences in diet among Red Snapper size-classes were due to low trophic position prey, such as pelagic zooplankton, being more abundant in the diet of larger (>500 mm) Red Snapper, while decapods and fish constituted a higher proportion of the diet of smaller individuals. Red Snapper consumed higher amounts of decapods at artificial (21.9% by mass) versus natural (14.8%) reef sites, but the habitat effect on diet was not significant. The habitat × DWH timing interaction was driven by a decrease in zooplankton consumed at both habitat types, increased benthic prey at natural reefs, and increased fish consumption at artificial reefs in post-DWH oil spill samples. Stable isotope data indicated a postspill increase in Red Snapper trophic position (15N enrichment) and an increase in benthic versus pelagic prey (34S depletion), both consistent with observed dietary shifts. Overall, results indicate shifts in Red Snapper diet and trophic position occurred following the DWH oil spill, thus the relative abundance of prey resources likely changed. Received May 30, 2014; accepted February 3, 2015

Polycyclic aromatic hydrocarbons (PAHs) are introduced into the marine environment via oil seeps/spills, riverine discharges, continental runoff, coastal erosion, and atmospheric deposition. An estimated 2.1 x 1010g of PAHs entered into the northern Gulf of Mexico (GOM) during the Deepwater Horizon (DWH) oil spill in 2010. It became evident following the oil spill that accurate quantification of ultimate fate of these potentially carcinogenic and/or mutagenic organic pollutants is extremely challenging. In general, very little is known about PAHs fate, distribution and accumulation in the open ocean ecosystems. This study determines the upper ocean vertical fluxes and sedimentary PAHs accumulation rates in the GOM. The concentrations of particulate and dissolved ΣPAH43 varied between 0.2-1.3 ng/L, and 24-58 ng/L, respectively during this study period in April 2012 and 2013. Dissolved ΣPAH43 were found to be orders of magnitude lower than the values reported during DWH oil spill. Sediment trap-based vertical fluxes of particulate ΣPAH43 varied between 2-8 μg m-2 d-1. The vertical fluxes are found to be an important loss term for PAHs in the upper ocean with 3-7% of total particulate PAHs inventory in the euphotic zone being lost daily via this pathway. The trap-independent PAHs fluxes estimated via 238U-234Th disequilibria are similar to the trap-derived fluxes, within the factor of three. The 234Th-based method provides a larger spatial coverage in relatively shorter time and thus can be more appropriate for upper ocean PAHs flux estimation in high traffic areas like the GOM. The concentrations and sediment ΣPAH43 accumulation rates in sediment cores collected one to three years after DWH varied between 26-160 ng/g and 1.4-63 ng cm-2y-1, respectively. Observed ΣPAH43 concentrations are similar to the background pre-spill values, indicating long term impacts of the oil spill on sediment PAHs to be minimal. The source diagnostic analyses suggest a noticeable change in PAHs composition in the last few years, towards lower molecular weight dominancy in PAHs profiles, attributed to the deposition of higher molecular weight PAHs byproducts by control combustion during the DWH oil spill. This study can serve as post-spill baseline PAHs concentrations and their accumulation rates in the GOM.

The focus of this study was to determine the long-term fate of oil-residues from the 2010 Deepwater Horizon (DwH) oil spill due to remobilization, transport, and re-distribution of oil residue contaminated sediments to down-slope depocenters following initial deposition on the seafloor. We characterized hydrocarbon residues, bulk sediment organic matter, ease of resuspension, sedimentology, and accumulation rates to define distribution patterns in a 14,300 km2 area southeast of the DwH wellhead (1,500 to 2,600 m water depth). Oil-residues from the DwH were detected at low concentrations in 62% of the studied sites at specific sediment layers, denoting episodic deposition of oil-residues during 2010–2014 and 2015–2018 periods. DwH oil residues exhibited a spatial distribution pattern that did not correspond with the distribution of the surface oil slick, subsurface plume or original seafloor spatial expression. Three different regions were apparent in the overall study area and distinguished by the episodic nature of sediment accumulation, the ease of sediment resuspension, the timing of oil-residue deposition, carbon content and isotopic composition and foram fracturing extent. These data indicate that resuspension and down-slope redistribution of oil-residues occurred in the years following the DwH event and must be considered in determining the fate of the spilled oil deposited on the seafloor.

During the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico a deep-sea hydrocarbon plume developed resulting in a rapid succession of bacteria. Colwellia eventually supplanted Oceanospirillales, which dominated the plume early in the spill. These successional changes may have resulted, in part, from the changing composition and abundance of hydrocarbons over time. Colwellia abundance peaked when gaseous and simple aromatic hydrocarbons increased, yet the metabolic pathway used by Colwellia in hydrocarbon disposition is unknown. Here we used single-cell genomics to gain insights into the genome properties of a Colwellia enriched during the DWH deep-sea plume. A single amplified genome (SAG) of a Colwellia cell isolated from a DWH plume, closely related (avg. 98% 16S rRNA gene similarity) to other plume Colwellia, was sequenced and annotated. The SAG was similar to the sequenced isolate Colwellia psychrerythraea 34H (84% avg. nucleotide identity). Both had genes for denitrification, chemotaxis, and motility, adaptations to cold environments and a suite of nutrient acquisition genes. The Colwellia SAG may be capable of gaseous and aromatic hydrocarbon degradation, which contrasts with a DWH plume Oceanospirillales SAG which encoded non-gaseous n-alkane and cycloalkane degradation pathways. The disparate hydrocarbon degradation pathways are consistent with hydrocarbons that were abundant at different times in the deep-sea plume; first, non-gaseous n-alkanes and cycloalkanes that could be degraded by Oceanospirillales, followed by gaseous, and simple aromatic hydrocarbons that may have been degraded by Colwellia. These insights into the genomic properties of a Colwellia species, which were supported by existing metagenomic sequence data from the plume and DWH contaminated sediments, help further our understanding of the successional changes in the dominant microbial players in the plume over the course of the DWH spill.

As the Deepwater Horizon disaster unfolds in the Gulf of Mexico, public health practitioners are having a sinking deja vu feeling. Once again, environmental disaster has struck, and tens of thousands of emergency responders—some professionals, but many more volunteers—have swung into action, potentially risking their health as they work to clean up the worst oil spill in U.S. history. Veterans of similar disasters are wondering if historical lessons learned can help keep the damage to a bare minimum. But a paucity of hard data on emergency responder health makes it difficult even to ask the right questions. “Emergency responders have not been adequately studied,” says Gina Solomon, codirector of the occupational and environmental medicine residency and fellowship program at the University of California, San Francisco, and a senior scientist with the Natural Resources Defense Council. “They tend to be ignored.” Professional emergency responders such as firefighters may not put much emphasis on health effects studies. “They are going to do what they need to do regardless of their own safety,” says Don Donahue, executive director of the Center for Health Policy & Preparedness at the Potomac Institute for Policy Studies, who has firefighters in his extended family. “They have to be a little crazy by definition.” That heroic approach is manna for the people they save, but firefighters may pay a price with disorders such as cancer. Studies of cancers in firefighters have had mixed results, but there is evidence linking this occupation with brain, thyroid, esophageal, bladder, testicular, prostate, and cervical cancers, as well as melanoma and Hodgkin disease (Bates1 and Ma et al.2 are two such studies). Health risks tend to be even greater for the many nonprofessional emergency responders who rush to the scene of crises such as oil spills, terrorist attacks, hurricanes, train derailments, and chemical releases. Those workers often don’t have the training and advanced equipment that protect professional emergency responders to some degree. These and many other factors make it a daunting challenge to protect the health of emergency responders during disasters.

Mercury bioaccumulation in tilefish from the northeastern Gulf of Mexico 2 years after the Deepwater Horizon oil spill: Insights from Hg, C, N and S stable isotopes

The Deepwater Horizon (DWH) oil spill significantly impacted the northern Gulf of Mexico (nGoM) deep benthos (>125 m water depth) at different spatial scales and across all community size and taxa groups including microbes, foraminifera, meiofauna, macrofauna, megafauna, corals, and demersal fishes. The resilience across these communities was heterogeneous, with some requiring years if not decades to fully recover. To synthesize ecosystem impacts and recovery following DWH, the Gulf of Mexico Research Initiative (GOMRI) Core 3 synthesis group subdivided the nGoM into four ecotypes: coastal, continental shelf, open-ocean, and deep benthic. Here we present a synopsis of the deep benthic ecotype status and discuss progress made on five tasks: 1) summarizing pre- and post-oil spill trends in abundance, species composition and dynamics; 2) identifying missing data/analyses and proposing a strategy to fill in these gaps; 3) constructing a conceptual model of important species interactions and impacting factors; 4) evaluating resiliency and recovery potential of different species; and 5) providing recommendations for future long-term benthic ecosystem research programs. To address these tasks, we assessed time series to detect measures of population trends. Moreover, a benthic conceptual model for the GoM deep benthos was developed and a vulnerability-resilience analysis was performed to enable holistic interpretation of the interrelationships among ecotypes, resources, and stressors. The DWH oil spill underscores the overall need for a system-level benthic management decision support tool based on long-term measurement of ecological quality status (EQS). Production of such a decision support tool requires temporal baselines and time-series data collections. This approach provides EQS for multiple stressors affecting the GoM beyond oil spills. In many cases, the lessons learned from DWH, the gaps identified, and the recommended approaches for future long-term hypothesis-driven research can be utilized to better assess impacts of any ecosystem perturbation of industrial impact, including marine mineral extraction.

The Deepwater Horizon (DWH) oil spill is one of the largest marine oil discharges in the United States [1]. The DWH oil spill released 4,900,000 barrels of crude oil into the northern Gulf of Mexico for the duration of 87 days. The proliferation of the oil discharge reached to more than 650 miles of the Gulf coastal habitats [2]. The wetlands of northern Gulf of Mexico were severely damaged with significant oiling to vegetation, soil, and wildlife. Although immediate short-term impacts of the DWH oil spill on coastal wetland vegetation are obvious, the long-term ecological impacts and recovery from this oil spill are practically unknown. The crude-oil deposition can have a dominant impact on the wetland ability to sequester carbon.

Chapter 16 - Assessing the Increase in Background Oil–Contamination Levels Along Alabama's Beaches Resulting From the Deepwater Horizon Oil Spill