VULNERABILITY OF COASTAL ENVIRONMENTS TO OIL SPILL IMPACTS

On the basis of field studies of five major oil spills and a review of the literature, major coastal environments have been classified on a scale of 1 to 10 in terms of potential vulnerability to oil spill damage. The scale emphasizes oil residence time, with consideration of initial biological impacts. Exposed rocky headlands and wave-cut platforms (1 and 2 on the Vulnerability Index) are generally least affected by an oil spill. Coarse-grained sandy and gravel beaches, which are subject to oil penetration and burial, are assigned intermediate index values of 4 to 7. Sheltered environments such as sheltered rocky coasts, salt marshes, and mangroves (index values of 8 to 10) are the environments most likely to be adversely affected by oil spills. For example, residence times of over 10 years are predicted for some salt marsh areas.