An oil spill-food chain interaction model for coastal waters

An oil spill-food chain interaction model, composed of a multiphase oil spill model (MOSM) and a food chain model, has been developed to assess the probable impacts of oil spills on several key marine organisms (phytoplankton, zooplankton, small fish, large fish and benthic invertebrates). The MOSM predicts oil slick thickness on the water surface; dissolved, emulsified and particulate oil concentrations in the water column; and dissolved and particulate oil concentrations in bed sediments. This model is used to predict the fate of oil spills and transport with respect to specific organic compounds, while the food chain model addresses the uptake of toxicant by marine organisms. The oil spill-food chain interaction model can be used to assess the environmental impacts of oil spills in marine ecosystems. The model is applied to the recent Evoikos-Orapin Global oil spill that occurred in the Singapore Strait.     

The effectiveness of double hulls in reducing vessel-accident oil spillage

While much work has been done in investigating determinants of oil spillage attributed to vessel accidents, little research has been conducted on the effectiveness of ship hull design in reducing marine pollution. This paper addresses whether the double-hull requirement reduces vessel-accident oil spillage. The volume of oil spillage due to oil-cargo vessel accidents was investigated using tobit regressions and an empirical data set of individual vessel accident pollution incidents investigated by the US Coast Guard from 2001 to 2008. The results indicate that the double hull design on average reduces the size of oil spills by 20% and 62% in tank barge and tanker ship accidents, respectively.     

Oil spill treatment products approval: the UK approach and potential application to the Gulf region

The environmental threat from oil spills remains significant across the globe and particularly in regions of high oil production and transport such as the Gulf. The ultimate damage caused can be limited by mitigation actions that responders deploy. The responsible and appropriate use of oil spill treatment products (e.g. dispersants, sorbents etc.) can offer response options that can result in substantial net environmental benefit. However, the approval and choice of what products to use needs careful consideration. The United Kingdom has had in place a statutory approval scheme for oil spill treatment products for 30 years. It is based on measures of efficiency and environmental acceptability. Two toxicity tests form an integral part of the assessment, the Sea test and the Rocky Shore test, and work on the premise that approved products will not make the situation significantly worse when added to spilled oil. This paper outlines the UK approach and how its rationale might be applied to the approval of products specific for the Gulf region. Issues such as species choice, higher temperatures and salinity and regional environmental conditions are considered.     

The three screen doors: can marine "protected" areas be effective?

The great majority of marine protected areas (MPAs) fail to meet their management objectives. So MPAs can be effective conservation tools, we recommend two paradigm shifts, the first related to how they are located and the second related to how they are managed. MPAs are unlikely to be effective if they are located in areas that are subject to numerous, and often uncontrollable, external stressors from atmospheric, terrestrial, and oceanic sources, all of which can degrade the environment and compromise protection. MPA effectiveness is also limited by low institutional and community capacity for management and inappropriate size with respect to ecological needs. In particular, the check list approach to management does not ensure that key threats are dealt with, or that management expenditures provide a quantifiable return. We recommend a business planning approach to MPA management, in which managers focus on the viability of the management system, i.e., the ability of the MPA to provide ecological goods and services to its target users over the long term.     

Formation, prevention and breaking of sea water in crude oil emulsions ‘chocolate mousses’

During the combatting of oil spills, the handling of the stable sea water in crude oil emulsions called ‘chocolate mousses’, either at sea or on the beach, is often a major problem.

A recent laboratory study of the formation and properties of such emulsions revealed the key roles played by asphaltenes and crystallized wax in their stability.

Viscosity measurements showed that mousses with 70% vol. sea water are thixotropic and may solidify after having been pumped into the hold of a salvage vessel or into a storage tank. During a search for novel chemicals for combatting oil spills we found a type of chemical additive that is effective in preventing the formation of mousses, in greatly improving the pumpability of mousses once formed and in decreasing their water content after recovery or during storage. The additive, designated LA 1834, has been tested successfully in the laboratory, on a semi-technical scale in cooperation with the Netherlands State Waterways Board and in the large-scale clean-up operation after a recent oil spill in Greece. The compound keeps oil from dispersing vertically into the water column, when applied to spilled oil or mousse on a sea water surface and holds promise of environmental acceptability.     

Marine spatial planning and oil spill risk analysis: Finding common grounds

A flow of key information links marine spatial planning (MSP) and oil spill risk analysis (OSRA), two distinct processes needed to achieve true sustainable management of coastal and marine areas. OSRA informs MSP on areas of high risk to oil spills allowing a redefinition of planning objectives and the relocation of activities to increase the ecosystem’s overall utility and resilience. Concomitantly, MSP continuously generates a large amount of data that is vital to OSRA. The Environmental Sensitivity Index (ESI) mapping system emerges as an operational tool to implement the MSP–OSRA link. Given the high level of commonalities between ESI and MSP data (both in biophysical and human dimensions), ESI tools (both paper maps and dynamic GIS-based product) are easily developed to further inform MSP and oil spill risk management. Finally, several other benefits from implementing the MSP–OSRA link are highlighted.     

Oil spills in Narragansett Bay: Comparison between federal and state records

Oil spill response in the US is divided among several jurisdictions due to separate and overlapping legislative and regulatory authority. In Rhode Island, data concerning oil spill incidents are kept by two agencies of the federal government and by one agency of the state government. Narragansett Bay and its tributaries are geographically in three jurisdictions; however, because of a tradition of good interagency cooperation, there were very few duplications in spill response. Because each agency has differing expertise and equipment, the types of spill incidents reported by each, if considered separately, present an entirely different picture of the nature of oil spills in this region. Assessment of oil spills as a source of pollution to coastal waters requires examination of all data, not only that from one agency. For Narragansett Bay and its tributaries, oil spills were a minor part of the total oil pollution budget.     

Changes in the marine pollution management system in response to the Amorgos oil spill in Taiwan

The Marine Pollution Control Act (MPCA) of Taiwan was promulgated on November 1, 2000, with the specific aim of controlling marine pollution, safeguarding public health, and promoting the sustainable use of marine resources. In addition to land-based pollution, oil spills are one of the most significant threats to the local marine environment largely on account of the some 30,000 tankers which pass through Taiwan’s coastal waters each year. In January 2001, two months after the enactment of this newly-introduced law, a Greek merchant vessel, the Amorgos ran aground in the vicinity of a national park on the southern tip of Taiwan, causing a serious oil spill and leading to considerable changes with regard to the marine pollution management system. The incident brought to the forefront many serious problems, such as a lack of experience, expertise as well as equipment required to respond to such disasters, as well as the ambiguous, unclear jurisdiction among related agencies. Thus, this paper reviews the incident of the Amorgos spill, identifies the major issues and lessons learned, and proposes several recommendations in an effort for Taiwan to further improve its marine pollution management system.     

Dynamics of oil product distributions in water and bottom sediments of the sea of Azov and the Black Sea after ship accidents in the Kerch Strait

The dynamics of concentrations of oil products spilled into the aquatic ecosystem as a result of accidents in the Kerch Strait is discussed. Provision is made for the analysis of the results of long-term monitoring and for the revealing of differences in concentrations and distribution of oil hydrocarbons in the Sea of Azov and in the Black Sea after emergency spills. The available information was used to outline the course of events that led to such redistribution of spilled mazut in marine ecosystems.     

Significance of cytochrome P450 system responses and levels of bile fluorescent aromatic compounds in marine wildlife following oil spills

The relationships among cytochrome P450 induction in marine wildlife species, levels of fluorescent aromatic compounds (FAC) in their bile, the chemical composition of the inducing compounds, the significance of the exposure pathway, and any resulting injury, as a consequence of exposure to crude oil following a spill, are reviewed. Fish collected after oil spills often show increases in cytochrome P450 system activity, cytochrome P4501A (CYP1A) and bile fluorescent aromatic compounds (FAC), that are correlated with exposure to polycyclic aromatic hydrocarbons (PAH) in the oil. There is also some evidence for increases in bile FAC and induction of cytochrome P450 in marine birds and mammals after oil spills. However, when observed, increases in these exposure indicators are transitory and generally decrease to background levels within one year after the exposure. Laboratory studies have shown induction of cytochrome P450 systems occurs after exposure of fish to crude oil in water, sediment or food. Most of the PAH found in crude oil (dominantly 2- and 3-ring PAH) are not strong inducers of cytochrome P450. Exposure to the 4-ring chrysenes or the photooxidized products of the PAH may account for the cytochrome P450 responses in fish collected from oil-spill sites. The contribution of non-spill background PAH, particularly combustion-derived (pyrogenic) PAH, to bile FAC and cytochrome P450 system responses can be confounding and needs to be considered when evaluating oil spill effects. The ubiquity of pyrogenic PAH makes it important to fully characterize all sources of PAH, including PAH from natural resources, e.g. retene, in oil spill studies. In addition, such parameters as species, sex, age, ambient temperature and season need to be taken into account. While increases in fish bile FAC and cytochrome P450 system responses, can together, be sensitive general indicators of PAH exposure after an oil spill, there is little unequivocal evidence to suggest a linkage to higher order biological effects, e.g. toxicity, lesions, reproductive failure.     

SAR observation and model tracking of an oil spill event in coastal waters

Oil spills are a major contributor to marine pollution. The objective of this work is to simulate the oil spill trajectory of oil released from a pipeline leaking in the Gulf of Mexico with the GNOME (General NOAA Operational Modeling Environment) model. The model was developed by NOAA (National Oceanic and Atmospheric Administration) to investigate the effects of different pollutants and environmental conditions on trajectory results. Also, a Texture-Classifying Neural Network Algorithm (TCNNA) was used to delineate ocean oil slicks from synthetic aperture radar (SAR) observations. During the simulation, ocean currents from NCOM (Navy Coastal Ocean Model) outputs and surface wind data measured by an NDBC (National Data Buoy Center) buoy are used to drive the GNOME model. The results show good agreement between the simulated trajectory of the oil spill and synchronous observations from the European ENVISAT ASAR (Advanced Synthetic Aperture Radar) and the Japanese ALOS (Advanced Land Observing Satellite) PALSAR (Phased Array L-band Synthetic Aperture Radar) images. Based on experience with past marine oil spills, about 63.0% of the oil will float and 18.5% of the oil will evaporate and disperse. In addition, the effects from uncertainty of ocean currents and the diffusion coefficient on the trajectory results are also studied.     

Impacts of a raw sewage spill on water and sediment quality in an urbanized estuary

A sewer main serving a large municipal wastewater system ruptured, discharging approximately 3,000,000 gallons (11,355,000 L) of raw human sewage into a multi-branched tidal creek estuary along the US East Coast. The biochemical oxygen demand caused severe hypoxia in the system, causing a large fish kill. The sewage load led to high fecal coliform bacteria concentrations in the creek (maximum of 270,000 CFU 100ml(-1)), which declined in an approximate logarithmic manner over the first few days. The spill caused elevated sediment fecal coliform bacteria and enterococcus counts that declined much more gradually than water column counts. Persistence of relatively high concentrations of fecal indicator bacteria in sediments for several weeks after the spill suggests that sediment sampling should be included in response to major sewage spills. The high concentration of nutrients in the spilled sewage led to several algal blooms. However, nutrient concentrations in the water column declined rapidly, demonstrating the value of conserving marshes because of their pollutant filtration function.     

Review of oil and HNS accidental spills in Europe: identifying major environmental monitoring gaps and drawing priorities

The European Atlantic area has been the scene of a number of extensive shipping incidents with immediate and potential long-term impacts to marine ecosystems. The occurrence of accidental spills at sea requires an effective response that must include a well executed monitoring programme to assess the environmental contamination and damage of the affected marine habitats. Despite a number of conventions and protocols developed by international and national authorities that focused on the preparedness and response to oil and HNS spills, much remains to be done, particularly in relation to the effectiveness of the environmental monitoring programmes implemented after oil and HNS spills. Hence, the present study reviews the status of the environmental monitoring programmes established following the major spill incidents over the last years in European waters, aiming at identifying the key monitoring gaps and drawing priorities for an effective environmental monitoring of accidental spills.     

Compound-specific stable carbon isotopic composition of petroleum hydrocarbons as a tool for tracing the source of oil spills

With the increasing demand for and consumption of crude oils, oil spill accidents happen frequently during the transportation of crude oils and oil products, and the environmental hazard they pose has become increasingly serious in China. The exact identification of the source of spilled oil can act as forensic evidence in the investigation and handling of oil spill accidents. In this study, a weathering simulation experiment demonstrates that the mass loss of crude oils caused by short-term weathering mainly occurs within the first 24h after a spill, and is dominated by the depletion of low-molecular weight hydrocarbons (相似文献   

An international comparison of governmental disclosure of hydrocarbon spills from offshore oil and gas installations

The cumulative effect of accidental spills from oil and gas extraction in the marine environment can have significant impacts on marine wildlife. Oil and gas operators are typically required to report spill data as part of a regulatory process. We conducted a survey of the public disclosure of hydrocarbon spill data for four countries, Australia, Canada, United Kingdom and United States. There was significant variation in the spill data statistics that were publicly reported by the regulators. No country provided full disclosure of spill data or follow-up actions taken by the regulator on their website. The lack of disclosure of spill data is of concern because the scale of environmental effects is more difficult to assess, insufficient information is available to assess the accuracy of predictions made in the environmental assessment process, and without consistency of spill reporting there is no method to compare regional differences of spill rates.     

Integrated assessment for establishing an oil environmental vulnerability map: Case study for the Santos Basin region,Brazil

The growth of maritime transport and oil exploitation activities may increase the risk of oil spills. Thus, plans and actions to prevent or mitigate impacts are needed to minimize the effects caused by oil. However, tools used worldwide to support contingency plans have not been integrated, thus leading to failure in establishing priority areas. This investigation aimed to develop indices of environmental vulnerability to oil (IEVO), by combining information about environmental sensibility to oil and results of numerical modeling of spilled oil. To achieve that, a case study concerning to oil spills scenarios in a subtropical coastal area was designed, and IEVOs were calculated and presented in maps, in order to make the information about the areas’ vulnerability more easily visualized. For summer, the extension of coastline potentially affected by oil was approximately 150 km, and most of the coastline presented medium to high vulnerability. For winter, 230 km coastline would be affected, from which 75% were classified as medium to high vulnerability. Thus, IEVO maps allowed a rapid and clearer interpretation of the vulnerability of the mapped region, facilitating the planning process and the actions in response to an oil spill.     

Development of oil hydrocarbon fingerprinting and identification techniques

Oil, refined product, and pyrogenic hydrocarbons are the most frequently discovered contaminants in the environment. To effectively determine the fate of spilled oil in the environment and to successfully identify source(s) of spilled oil and petroleum products is, therefore, extremely important in many oil-related environmental studies and liability cases. This article briefly reviews the recent development of chemical analysis methodologies which are most frequently used in oil spill characterization and identification studies and environmental forensic investigations. The fingerprinting and data interpretation techniques discussed include oil spill identification protocol, tiered analytical approach, generic features and chemical composition of oils, effects of weathering on hydrocarbon fingerprinting, recognition of distribution patterns of petroleum hydrocarbons, oil type screening and differentiation, analysis of “source-specific marker” compounds, determination of diagnostic ratios of specific oil constituents, stable isotopic analysis, application of various statistical and numerical analysis tools, and application of other analytical techniques. The issue of how biogenic and pyrogenic hydrocarbons are distinguished from petrogenic hydrocarbons is also addressed.     

Petroleum biodegradation and oil spill bioremediation

Hydrocarbon-utilizing microorganisms are ubiquitously distributed in the marine environment following oil spills. These microorganisms naturally biodegrade numerous contaminating petroleum hydrocarbons, thereby cleansing the oceans of oil pollutants. Bioremediation, which is accomplished by adding exogenous microbial populations or stimulating indigenous ones, attempts to raise the rates of degradation found naturally to significantly higher rates. Seeding with oil degraders has not been demonstrated to be effective, but addition of nitrogenous fertilizers has been shown to increase rates of petroleum biodegradation. In the case of the Exxon Valdez spill, the largest and most thoroughly studied application of bioremediation, the application of fertilizer (slow release or oleophilic) increased rates of biodegradation 3–5 times. Because of the patchiness of oil, an internally conserved compound, hopane, was critical for demonstrating the efficacy of bioremediation. Multiple regression models showed that the effectiveness of bioremediation depended upon the amount of nitrogen delivered, the concentration of oil, and time.     

Mexican oil spill: A toxicity study of oil accommodated in seawater on marine invertebrates

The Mexican Ixtoc oil well blew out on 3 June, 1979. Since then more than 3.5 × 10⁵ tonnes of crude oil have entered the Gulf of Mexico. This is probably the largest oil spill in the world's history. Two months later (7 August, 1979), the spilled oil began moving to the Texas coastal waters and the well is not yet capped. Although laboratory tests showed that the aged oil was not acutely toxic to some marine invertebrates, further work needs to be conducted to determine its possible chronic effects on sensitive ecosystems such as the Laguna Madre.