Session: 07-9-01 Scenario-Based Risk Management for Ice-Covered Waters: LRF- CEPOLAR Activities

Paper Number: 80903

80903 - Holistic, Quantitative and Spatiotemporally Explicit Oil Spill Risk Assessment in Marine Arctic 

Commercial and other shipping is anticipated to increase the Arctic, as climate change extends the ice-free period in high-latitude areas. Increased shipping activities can have various negative impacts on the relative pristine arctic environment. One of the major threats to marine and coastal ecosystems are large-scale oil spills resulting from shipping accidents. Proactive oil spill risk management calls for quantitative and spatiotemporally explicit risk assessments that acknowledge high uncertainties typical for the Arctic. Generally, oil spill risk assessment combines the probability of spill occurrence with an analysis of the consequences of spill. However, both of these factors are challenging to assess reliably in the Arctic due to limited data resources. Here we present a recently developed general framework for probabilistic oil spill risk assessment in Arctic marine areas, and apply the approach to a case study in the Kara Sea, the westernmost of the Russian arctic seas. The ecological consequences are assessed by combining seasonally varying estimates for species distributions and for oil type -specific spreading of oil with the estimates for species-specific exposure potentials and sensitivities to oil. The uncertainties related to these factors are summarized by using probability distributions. The analysis is supplemented with the seasonally varying accident probabilities to calculate the overall oil spill risk. As a case study, we assess the risk related to acute impact of a 42 000 m³ oil spill on adult populations of three arctic marine mammal species living in the Kara Sea, i.e. polar bear (Ursus maritimus), ringed seal (Pusa hispida), and walrus (Odobenus rosmarus). The assessment is conducted for three shipping routes, four oil types (light, medium, heavy, and extra heavy oil) and three different seasons (spring, summer, and autumn). Further, we assess the probability of vessel accidents along the five shipping routes, and combine this information with the estimated ecological consequences of oil spills. We demonstrate that the risks differ between routes, oil types and seasons. We discuss the importance of comprehensive oil spill risk assessments in the Arctic context, and the implications of our study to the management of shipping-induced risks.

Presenting Author: Jarno Vanhatalo University of Helsinki

Authors:

Jarno Vanhatalo University of Helsinki
Inari Helle Natural Resources Institute Finland