Oil Spill Response Limited (OSRL) is a British firm specializing in managing oil spills. The company was founded in 1985 and employs about 300 people at nine locations. Shareholders are all major oil companies such as BHP Billiton, Chevron Corporation, Eni, ExxonMobil, Petronas, Saudi Aramco, Royal Dutch Shell, Statoil and Total.
We examined the role of endothelium-derived relaxing factor (EDRF) in the increase in pulmonary blood flow caused by increasing oxygen tension in the lungs of the fetus. Fetal lambs at 133 days of gestation were instrumented for intrauterine measurement of pulmonary arterial, left atrial, and amniotic fluid pressure and pulmonary blood flow. Three days later oxygen tension in the pulmonary arterial blood of the fetus was doubled by having the ewe breathe 100% oxygen at 3 atm absolute pressure. In the control fetuses (n = 5), hyperbaric oxygenation increased pulmonary blood flow eightfold. Blocking EDRF production by infusing 45 mg of N(G)-monomethyl-L-arginine into the superior vena cava of the fetus over 5 min starting 30 min after the beginning of hyperbaric oxygen reversed the increase in pulmonary blood flow (n = 5). Blocking EDRF production by infusing N(G)-nitro-L-arginine at 1 mg/min for 60 min starting 30 min before hyperbaric oxygen blunted the initial increase in pulmonary blood flow and eliminated it by the end of the experiment (n = 5). As hyperbaric oxygen did not significantly alter pulmonary arterial or left atrial pressure, changes in pulmonary vascular conductance paralleled those in pulmonary blood flow. We conclude that the majority of the vasodilation of the fetal pulmonary circulation caused by increasing oxygen tension is mediated by EDRF. We speculate that EDRF is involved in maintaining low vascular tone at the relatively high oxygen tension of the postnatal lung.
Under certain conditions, dispersed crude oil in the sea combines with organisms, organic matter, and minerals to form marine oil snow (MOS), thereby contributing to the sinking of oil to the seafloor. Marine microbes are the main players in MOS formation, particularly via the production of extracellular polymeric substances. Distinct groups of microbes also consume the majority of the hydrocarbons during descent, leading to enrichment of the less bioavailable hydrocarbons and asphaltenes in the residue. Here we discuss the dynamics of microbial communities in MOS together with their impacts on MOS evolution. We explore the effects of dispersant application on MOS formation, and consider ways in which laboratory experiments investigating MOS formation can be more representative of the situation in the marine environment, which in turn will improve our understanding of the contribution of MOS to the fate of spilled oil.
ABSTRACT In 1984, the Tropical Oil Pollution Investigations in Coastal Systems (TROPICS) experiment began in Bahia Almirante on the Caribbean coast of Panama. This study sought to compare the impacts of a severe, but realistic spill of untreated crude oil versus chemically treated (dispersed) crude oil on tropical marine reef, sea-grass, and mangrove ecosystems. The aim of the study was to identify and evaluate the environmental trade-offs of dispersant use in tropical marine and subtidal systems. As a result of continuing research at the site, the study became one of the most comprehensive field experiments examining the long-term impacts of oil and dispersed oil exposures in nearshore tropical communities. Consequently, TROPICS has been the foundational and seminal field study which served as the historical antecedent for Net Environmental Benefit Analysis (NEBA), as well as the basis for follow-on Spill Impact Mitigation Analysis (SIMA) and Comparative Risk Analysis (CRA) for oil spill planning, preparation, and response. From the initial experiment in 1984, through three decades of study and data collection visits, the coral reef, seagrass, and mangrove communities have exhibited significantly different damage and recovery regimes, depending on whether the sites were exposed to non-treated crude oil or dispersed crude oil. While this study does not definitively determine whether or not dispersants should be applied in tropical nearshore environments, it is illustrative of the environmental and ecosystem trade-offs between surface oil impacts to the shoreline, compared to water column exposure from chemically dispersed oil. This paper provides an overview of the results and observations reported in numerous previous TROPICS publications, as a progression of damage and recovery over time. With this perspective, planners and responders can use this study to predict what damages/recoveries may be expected from an oil spill incident in this environment. The results of the TROPICS experiment are examined within the context of this recent parallel research from the perspective of ongoing implications for oil spill preparedness and response.
There are many factors that contribute to the complexity of co-ordinating effective oil spill response in remote locations. This poster will focuses on the complexities associated with unique risks encountered in remote locations, with an emphasis on water resources. The hydrogeological setting must be understood if oil spill response organisations (OSRO) are to co-ordinate a response that affords the environment and local populations the best level of protection. The relationship between communities and their environment should be clearly understood as part of preparedness work. This will facilitate the implementation of a suitable and timely response with pre-defined ‘end-points’.
ABSTRACT> Spill response equipment is often kept for prolonged periods until required; such equipment would be operated continuously when deployed, often under harsh conditions detrimental to any equipment. Uncertainty in the reliability of response equipment bears significant risks to operational safety and incident management, especially in critical operations that have a widespread impact during an incident. A qualitative risk assessment was conducted on OSRL's equipment stockpile, considering their known history of breakdown (probability) and foreseeable impact (severity) during an incident. The resultant matrix categorises them into five different risk levels from low to very high. Response equipment is categorised in accordance with OSRL's prescribed service life, a set of guidance documents based on the organisation's operational experience and consultation with various manufacturers and other users, forming baseline data of the stockpile. Coupled with the results from the risk assessment conducted, it provides a wider understanding of response equipment from a risk-based perspective. The existing equipment risk profile is mapped out using the above method to provide a high-level overview to decision-makers. Upon discussion with stakeholders, the desired position on the risk profile can be achieved by replacing identified critical equipment or extending the service life of non-critical equipment. A risk-based approach allows a logical prioritisation of actions to be undertaken, in line with the organisation's strategy and enables decision-makers to make plans for a sustainable equipment reinvigoration program over a projected budget and period. With continual monitoring and assessment in place during planned maintenance, timely feedback can be provided to decision-makers on any changes to risk profile in the equipment stockpile; this not only helps in accurately updating the equipment condition, but also enables the early detection of equipment failure and prompts timely actions for resolution. Response equipment constitutes a valuable resource in response readiness; an evolved approach to the management of response equipment is discussed here and can be applied for Tier 1 and 2 response equipment to assure equipment reliability.
