ESI shoreline classifications provide the information necessary to make these decisions. Shoreline sensitivity classifies sections of shoreline into habitats according to geomorphological characteristics, sensitivity to spilled oil, natural persistence of oil, and ease of cleanup. Ranking is based on an understanding of the complete coastal environment including the relationships between physical processes and substrate that produce specific shoreline types and predictable patterns in oil behavior and sediment transport. Biological resources in ESI maps include oil-sensitive animals and plants, with information at the species level. Special attention is given to areas where concentrations of oil-sensitive species occur, such as breeding grounds, nesting habitats, and staging areas.
Information is presented by specific life stages and months of occurrence.
ESI maps also identify human use resources that might be damaged by oil or response actions. Many local organizations are developing information that builds on ESI content. NOAA is assisting these efforts by publishing guidelines that reflect ESI classifications. Since their inception in 1979, ESI atlases have been prepared for most of the U.S. shoreline, including the Great Lakes, Alaska, Hawaii, and the Trust Territories. Recent work has focused on extending the original methodology for open coastal areas to inland rivers, and smaller ponds and streams.