A model that can evaluate the ecological risk posed to the Arctic marine ecosystem is presented in this paper. The proposed model is aimed at evaluating the risk of an accidental oil release. The model incorporates a release and dispersion model, fate and transport model, and ecotoxicological modelling. Uncertainties in the proposed model and data are addressed through a probabilistic framework implemented using a fugacity model to estimate the exposure concentration in the different media that are in contact with oil. This is the focus of this paper. The 95th percentile of Predicted Exposure Concentration (PEC_95%) is compared with the 5th percentile of the Predicted No Effect Concentration (PNEC_5%) to produce a Risk Quotient (RQ) profile, which indicates the level of risk posed to the Arctic marine ecosystem. The application of the proposed model is illustrated through a case study. The RQ obtained is useful for making decisions on the management of safety for Arctic marine ecosystems, such as setting operational goals to prevent accidents and for designing emergency preparedness plans. The uniqueness of this work in comparison to ealier studies is that, the methodology takes into account all the significant component models needed to address a potential oil spill in a probabilistic way and demonstrated in an Arctic setting. This study also shows that the methodology is useful as a first step to decision making in the absence of data on accidental releases in the Arctic marine waters.

@en

This paper presents a methodology for the analysis of Arctic shipping accident scenarios using Bayesian Networks (BN). The proposed methodology is applied to a scenario involving a collision between a vessel and an iceberg. The study aims to identify the most significant causative factors to the potential accident scenarios. It is achieved by undertaking a sensitivity analysis study. The results inform the development of measures to avoid and control accidents during Arctic shipping.

@en

The prospect of shipping in the Arctic poses potential oil spill risk. To minimize this risk, it requires detailed evaluation of the effectiveness of measures to be used to control and mitigate the spill. In this paper, a model is presented to study and evaluate strategies for reducing the effects of oil spills on the Arctic marine ecosystem. Risk is estimated by considering exposure concentration and no-effect reference concentration. The exposure concentration is modelled using a fugacity approach and the response is estimated based on ecotoxicology studies. Control, design, and response measures are studied to ensure that risks remain within an acceptable range. The proposed model helps to evaluate efficacy of specific measures and combinations of measures on anticipated spill scenarios. A case study is used to illustrate the application of the proposed model. In the case study, the model is applied to the Exxon Valdez oil spill to identify the most effective combination of the measures to employ before and after the accident. The case study illustrates how the proposed model can assist decision makers to better prepare for potential oil spill in an Arctic marine ecosystem.@en

This paper presents a model of oil weathering and transport in sea ice. It contains a model formulation and scenario simulation to test the proposed model. The model formulation is based on state-of-the-art models for individual weathering and transport processes. The approach incorporates the dependency of weathering and transport processes on each other, as well as their simultaneous occurrence after an oil spill in sea ice. The model is calibrated with available experimental data. The experimental data and model prediction show close agreement. A sensitivity analysis is conducted to determine the most sensitive parameters in the model. The model is useful for contingency planning of a potential oil spill in sea ice. It is suitable for coupling with a level IV fugacity model, to estimate the concentration and persistence of hydrocarbons in air, ice, water and sediments for risk assessment purposes.

@en

Improved understanding of ecological risk associated with Arctic shipping would help advance effective oil spill prevention, control, and mitigation strategies. Ecological risk assessment involves analysis of a release (oil), its fate, and dispersion, and the exposure and intake of the contaminant to different receptors. Exposure analysis is a key step of the detailed ecological risk assessment, which involves the evaluation of the concentration and persistence of released pollutants in the media of contact. In the present study, a multimedia fate and transport model is presented, which is developed using a fugacity-based approach. This model considers four media: air, water, sediment, and ice. The output of the model is the concentration of oil (surrogate hydrocarbons-naphthalene) in these four media, which constitutes the potential exposure to receptors. The concentration profiles can subsequently be used to estimate ecological risk thereby providing guidance to policies for Arctic shipping operations, ship design, and ecological response measures.

@en

This paper describes the essence of establishing a dynamic fugacity model, mainly in the framework of assessing the potential risk posed by oil spills during Arctic shipping. Key to evaluating this risk is the fate and transport processes as they occur in ice-covered waters. A review of relevant weathering and transport processes is therefore presented. The study shows that more understanding is needed of the behavior of oil in ice for assessing the risk posed during Arctic shipping.@en