Oil spill impact minimization under uncertainty: Evaluating contingency simulations of the Prestige accident

In order to develop a rationale for conflicts which arise in the context of oil spill contingency policies, we propose an integrated framework of simulation and valuation methods. The model system is tested for the M/T Prestige accident 270 km off the Spanish coast where it is able to assess ecological and economic oil spill impacts for a set of management options. In the Prestige case, these were given by different hypothetical towing directions. Uncertainty resulting from lacking information about the sinking probability, pollution impacts or different weighting schemes which represent specific interests of main stakeholder groups involved is taken into account by a systematic parameter variation. The results are discussed on the basis of recently available data on recovery costs and sectorial economic losses. We equivocally identified clearly one worst response option and two almost equally evaluated best options. Effects of the uncertainties were relatively moderate so that the approach turned out to be suitable for an ex ante contingency response, as well as for ex post evaluations of spill abatement measures. It also supports a consensus building by making relevant information transparent to a larger group of stakeholders.