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After oil spills, the floating oil may interact with suspended minerals to form the oil-mineral aggregates (OMAs) in turbulent environments. In this work, a flume was used in conjunction with a settling device to investigate the vertical distribution and properties of OMAs formed by different clay minerals. The density and size of OMAs depend on the density and surface properties of the constituent particles, which also affect the vertical distribution of dispersed oil. Density of oil-montmorillonite aggregates increased from 1165 to 1897 kg/m

The present study investigated the toxic effects of parental (maternal/paternal) exposure to heavy fuel oil (HFO) on the adult reproductive state, gamete quality and development of the offspring of the sea urchin Strongylocentrotus intermedius. Adult sea urchins were exposed to effluents from HFO-oiled gravel columns for 7 days to simulate an oil-contaminated gravel shore, and then gametes of adult sea urchins were used to produce embryos to determine developmental toxicity. For adult sea urchins, no significant difference in the somatic size and weight was found between the various oil loadings tested, while the gonad weight and gonad index were significantly decreased at higher oil loadings. The spawning ability of adults and fecundity of females significantly decreased. For gametes, no effect was observed on the egg size and fertilization success in any of the groups. However, a significant increase in the percentage of anomalies in the offspring was observed and then quantified by an integrative toxicity index (ITI) at 24 and 48 h post fertilization. The offspring from exposed parents showed higher ITI values with more malformed embryos. The results confirmed that parental exposure to HFO can cause adverse effects on the offspring and consequently affect the recruitment and population maintenance of sea urchins.

When a ship in need of assistance has requested a place of refuge with regards to the maritime administration, deciding on the most suitable form of refuge is often both a political and technical problem. To avoid opposition by local communities, a decision model responding to such ship requests is generally established to enable the refuge designation on a case-by-case basis. Within this framework, a step-by-step ranking process is proposed, first selecting indices for potential candidate refuge sites according to the purpose of requesting refuge, with all indices then ordered by pairwise comparison. The weight of each index is determined according to the tone word used for adjacent comparison, and the suitability score for each candidate port obtained. The model is then applied to a hypothetical ship accident in the Bohai Sea in China, which further illustrates the envisaged response process and provides a solution to contemporary maritime administration.

To further understand the underlying mechanisms involved in the developmental toxicity of crude oil and chemically dispersed crude oil on fish early-life stages (ELS), zebrafish (Danio rerio) embryos were exposed to GM-2 chemical dispersant (DISP), low-energy water-accommodated fractions (LEWAF), and chemically enhanced WAF (CEWAF) of Merey crude oil at sublethal concentrations for 120 h. We employed the General Morphology Score (GMS) and General Teratogenic Score (GTS) systems in conjunction with high-throughput RNA-Seq analysis to evaluate the phenotypic and transcriptomic responses in zebrafish ELS. Results showed that ΣPAHs concentrations in LEWAF and CEWAF solutions were 507.63 ± 80.95 ng·L−1 and 4039.51 ± 241.26 ng·L−1, respectively. The GMS and GTS values indicated that CEWAF exposure caused more severe developmental delay and higher frequencies of teratogenic effects than LEWAF exposure. Moreover, no significant change in heart rate was observed in LEWAF treatment, while CEWAF exposure caused a significant reduction in heart rate. LEWAF and CEWAF exposure exhibited an overt change in eye area, with a reduction of 4.0% and 25.3% (relative to the control), respectively. Additionally, no obvious impact on phenotypic development was observed in zebrafish embryo-larvae following DISP exposure. Significant changes in gene expression were detected in LEWAF and CEWAF treatments, with a total of 957 and 2062 differentially expressed genes (DEGs), respectively, while DISP exposure altered only 91 DEGs. Functional enrichment analysis revealed that LEWAF and CEWAF exposure caused significant perturbations in the pathways associated with phototransduction, retinol metabolism, metabolism of xenobiotics by cytochrome P450, and immune response-related pathways. Our results provide more valid evidence to corroborate the previous suggestion that ocular impairment is an equal or possibly more sensitive biomarker than cardiotoxicity in fish ELS exposed to oil-derived PAHs. All these findings could gain further mechanistic insights into the effects of crude oil and chemical dispersant on fish ELS.

After spill, the dispersed oil droplets may collide with suspended particulate matter in the water column to form oil-particle aggregates (OPAs) in turbulent environments. It may be an effective pathway to stabilize the oil by taking advantage of the particulate matter to clean up the contaminated waters. A theoretical model in Payne et al. (2003) is adopted to describe the oil-particle aggregation, and a solution method is proposed and validated against a group of experiments. The effect of the particle size and mass concentration on the aggregation has been examined quantitatively in detail. The particles and the oil droplets are consumed at a fixed ratio. Under the same mass concentration, smaller particles can trap more oil droplets, while larger particles tend to interact more quickly with the oil. The oil-particle aggregation rate and the oil trapping efficiency mainly depend on the particle concentration. The theoretical model is applied to predict the decrease of the dispersed oil in nearshore environments, based on the parameters obtained from the experiments. It is efficient to promote the oil-particle aggregation by increasing the particle concentration in the closed bay. In the open sea, the decrease of the dispersed oil can be effectively enhanced by increasing the particle concentration when it is below 0.50 kg/m3. The information presented in this paper can serve to predict the fate of the dispersed oil in coastal waters and provide technical support for oil spill management strategies.

This work analyses the specific potential spill scenarios for future oil exploitation and transportation activity in Guinean waters. The analysis was carried out by using the DEEPBLOW and (OSCAR) 3-dimensional model system from SINTEF. A spill using 100 t as a “worst case” reference scenario of marine crude oil demonstrates the rapidity with which such a spill will dissipate naturally. Guinean southwest (SW) and north–northwest (NNW) winds directions were selected. A comprehensive environmental impact assessment has been carried out, including the assessment of the impact from oil spills. The modeling identified environmentally sensitive areas which could potentially be influenced by an oil spill. Also, the potential of surface contaminant risk and maximum concentration were modeled; the total area of the oil spill and area of thick oil concentration were predicted; spill mass balance area and sediment risks and maximum concentration scenarios are shown. The simulation results demonstrate the usefulness of the models as tools for guidance of environmental impact risk assessment of spilled oil during an actual blowout event; and its application will help to set up an eventual spill planning response strategies and protect the country's marine environment against oil spill accidents and manage oil exploitation and transport.

Over the years there has been many well documented cases of major oil pollution from leaked offshore oil rigs, ships in distress and from coastal oil facilities. In response to concerns about the possibility of a major oil spillage occurring along the coast of Guinea, the Guinean government drew up a plan and organisation. The purpose of this research was to develop Guinean Marine Oil Spill Response Information System. To do this, we simulated an oil spill concentration transport. The results show that the numerical model in oil spill accident simulation is important in allowing setting up of possible response and contingency planning. From the results we conclude that, the search strategies for futures responses and contingency planning to possible oil spill case in Guinean coasts has been clarified. Implications of research findings allow international community to consider reasonable estimation of spilled oil trajectory with limited environmental input data.