The Deepwater Horizon (DWH, 2010) and Ixtoc-I (1979-1980) oil spills, separated by thirty years and over 600 nautical miles in the Gulf of Mexico, are the two largest submarine oil well blowouts in global history. Over the past two GoMRI funding cycles, the C-IMAGE consortium has studied these two blowouts through the lenses of GoMRI themes 2 and 3: chemical evolution and biological degradation of the petroleum/dispersant system, and environmental effects of the petroleum/dispersant system. Through an integrated series of field-based, laboratory and modeling studies, previous C-IMAGE research has sought to advance understanding of the fundamental processes and mechanisms involved in marine blowouts and their environmental consequences, ensuring that society is better-prepared to mitigate future events. In particular, C-IMAGE research has documented extensive accumulation of oil at the sea bottom resulting from both spills through a process now recognized as marine oil snow sediment and flocculent accumulation (MOSSFA). Coastal surveys in the Campeche area off Mexico revealed large quantities of weathered oil 37+ years since the Ixtoc-I spill. Gulf-wide surveys of fish, microbes, and sediments provide important new baselines of oil contamination and spatially resolved indicators of relative resilience of ecosystems to oil spills. Research on the physical processes of spills at high pressure have revealed the criticality of considering “live” oil (charged with methane gas) as a basis of understanding how or if dispersant application may have contributed to the formation of deep droplet plumes. The large pressure drop at the rim of the broken blowout preventer resulted in a rapid degassing of oil droplets, shattering them into very small particles. Controlled exposures of various species to oil and dispersants has resulted in important new insights into the organismal, immunogenic, genomic and ecosystem-level impacts of oil and dispersant exposures. These and other findings represent critical new knowledge developed by C-IMAGE researchers that are seminal to future oil spill response.
This proposal focuses on three (“CSI”) priorities:
- Continuing promising research threads that have emerged from previous C-IMAGE-initiated research
- Synthesizing research findings commissioned by GoMRI, government agencies, and other entities
- Integrating information across fundamental research domains including field-based sampling, laboratory experimentation and modeling.
In combination, these research approaches present a powerful learning environment.
The integration of knowledge is imperative if new, disruptive science is to impact response and recovery strategies for future oil spills. To motivate this integration, we pose a series of “legacy science questions” reflecting key unknowns that, if sufficiently answered, would significantly improve oil spill response, viz:
- What was the relative contribution of dispersants and ambient environmental conditions (depth/temperature, oil type, reservoir conditions) to the formation of deep oil droplet plumes in DWH? How would this scenario change under differing environmental conditions (e.g., different crude, depths, temperatures, etc.) and oil spill response options?
- What conditions lead to a MOSSFA event? In the advent of another large spill in the Gulf, can we predict when/where and with what intensity a MOSSFA event would occur?
- How resilient was the Gulf of Mexico marine ecosystem to the impacts of DWH and Ixtoc-I? Would other regions of the Gulf be more/less resilient to a large-scale spill?
- How persistent and widespread are PAHs and other oil components in the environment? How does DWH relate to other sources in the oil pollution budget of the Gulf of Mexico?
- If a similar large-scale spill occurred in another area of the Gulf, would we expect the same rates of biodegradation in the water column? In sediments?
- Are there adequate pre-spill baselines of factors related to response and restoration and for quantitative assessment of impacts and damage?
- How can the research conducted under the auspices of GoMRI be better synthesized with other research findings and used in policy formulation, disaster response and damage assessments in the future? What are the training and expertise requirements for government and industry oil spill responders?
To address these questions, C-IMAGE-III will take advantage of its large quantity of previously-obtained, field-derived samples, as well as investments in built experimental infrastructure and increasing sophistication of physical and ecological modeling systems. Field surveys of sediments, fish, water and microbes provide both time-series data documenting degradation of the DWH signal in the various sample matrices, and broad-scale (basin-wide) samples that allow comparisons of the DWH-affected area with other regions of the Gulf (including Mexico and Cuba). Additional analyses of sediment cores, fish tissues and DNA, and microbial samples will focus on the comprehensive sample archive. In particular, this effort will focus on combining C-IMAGE sampling with other information (e.g., NRDA and other GoMRI-sponsored research) to develop basin wide maps of key environmental parameters such as sediment contamination and characteristics (e.g., type and grain size), demersal fish PAHs, 14C and 13C levels, sediment redox potentials, marine mammal abundance, microbial community structure and other baseline characteristics relevant to understanding the extent of hydrocarbon contamination in the Gulf and impacts of potential future spills. These maps will help in understanding the Gulf oil budget in the context of large spills.
Major research facilities for conducting controlled experimentation on spill effects were developed, tested, and used as part of previous funding cycles. High pressure research facilities have resulted in new insights regarding how deep oil/gas spills (multi-phase flows) behave, and state-of-the-art facilities for exposure trials of fish and invertebrate communities are built. A number of additional key experiments will be conducted in these facilities, including developing new approaches for scaling up experimental results of oil physics from the laboratory to the field using the concept of turbulent kinetic energy (TKE). Similarly, oil exposure facilities will be used to understand the heritability of oil exposure effects, and to compare exposure effects among fishes with different life history patterns (e.g., pelagic vs. benthic).
Integrating field, laboratory and modeling approaches is a key to both understanding mechanisms controlling the fate and effects of oil/dispersants in the environment and especially for making predictions of how any future spills may evolve. By generalizing model approaches, the predictive models gain value not only Gulf-wide, but globally. C-IMAGE teams will use both physical modeling systems and ecological models to further develop oil spill response predictions.
Synthesis of research findings will include production of a two-volume series of books interpreting relevant findings. The working titles of these two volumes are, respectively: Deep Oil Spills: Facts, Fate and Effects, and Scenarios and Responses to Future Deep Spills: Fighting the Next War. The first volume will integrate key findings from research in response to DWH, as well as information derived from the Ixtoc-I blowout and the Deep Spill experiment in 2000. Chapters will be co-authored by researchers supported by C-IMAGE, other GoMRI grantees, government scientists and industry-sponsored researchers. The second volume will focus on the evolution and environmental impacts of a number of simulated oil spills throughout the deep parts of the Gulf of Mexico. Laboratory experiments simulating differing pressures, temperatures and with different oil types will support these scenarios. The second volume will also include a synthesis of training and expertise requirements for the future workforce, from the perspectives of government and industry oil spill responders and academic institutions. C-IMAGE-III researchers will also edit and substantially author a special issue of the Marine Technology Society Journal dedicated to describing the technological advances in oil spill research pioneered by a broad cross-section of GoMRI-funded researchers.
Outreach activities will be a focal point of the C-IMAGE-III consortium. C-IMAGE-III will support dedicated workshops involving government policy makers, industry, agency scientists and academics. The goal of these workshops will be to peer review the evidence supporting particular response strategies (e.g., sub-surface dispersant injection ¡VSSDI), and advising on ad hoc response strategies in the future (e.g., freshwater flushing of coastal areas, construction of sand berms, etc.). Public outreach will include a variety of media, e.g., podcasts, focused on oil spill science and the legacy of GoMRI-sponsored research.