Environmental Sensitivity Index Guidelines, Version 4.0

Environmental Sensitivity Index (ESI) maps and data provide a concise summary of coastal resources at risk if an oil spill occurs nearby (Figure 1.1). ESI maps are comprised of three types of information: 1. Shoreline Classification – ranked according to a scale relating to sensitivity, natural persistence of oil, and ease of cleanup. 2. Biological Resources – including oil-sensitive animals and rare plants, as well as habitats used by oil-sensitive species or that are themselves sensitive to oil spills, such as submersed aquatic vegetation and coral reefs. 3. Human-Use Resources – specific areas that have added sensitivity and value because of their use (such as beaches, parks and marine sanctuaries, water intakes, and archaeological sites), areas that may be useful in the event of a response (such as boat ramps and access points), jurisdictional boundaries, and resources that may themselves pose a risk.