Western Australian marine oil pollution risk assessment: identification of protection priorities

Abstract

The Western Australian Department of Transport (DoT) is the hazard management agency (HMA) for marine oil pollution in Western Australia (WA). DoT initiated the WA marine oil pollution risk assessment (WAMOPRA), a detailed assessment of oil spill risk in Western Australian State waters. It comprised two components. The first component evaluated protection priorities of the receiving environment to assess potential consequences of marine oil pollution. The second component assessed the likelihood, size, location and type of marine oil pollution. Protection priority outputs from component one were modelled with spill risk from component two, to give an overall risk profile for the State. For management purposes, State waters were divided into seven zones and smaller shoreline cells (~10 km × ~20 km). Geospatial datasets representing the various receptors identified were collated and grouped into the following five categories: Protected fauna; Protection areas; Cultural heritage; Economic; and Social, amenity and recreation. Using a multi-criteria analysis approach, the spatial data layers for each receptor identified were assigned a ranking from one (very low priority) to five (very high priority) for protection. The effects of both floating and dissolved hydrocarbons were ranked. These rankings were then used to produce a map showing very low to very high priorities of the shoreline cells for each category. The outcome of this project is the largest single assessment of protection priorities (~13000 km of coastline), undertaken across a highly variable coastline, using a standard and repeatable approach that can be applied across Australia.