Environmental Sensitivity Index (ESI) maps are used in oil spill response to help determine resources at risk and guide response strategies. ESI is a measure of a coastal zone's natural and socio-economic resources as depicted through the use of maps, atlases, and tables. ESI maps are used in oil spill impact evaluation, prevention, clean up, and contingency planning activities.

There are six ESI atlases for the state of Florida. Sector Jacksonville is covered by two of these atlases with a small portion of it falling into an area covered by Georgia's ESI Atlas. These atlases have been converted to an interactive Adobe PDF format. The links below will open a hyperlinked Index map that can be used to navigate to each individual map and its associated biological (Resources at Risk) table.

St Johns River ESI Atlas (pdf, 373 kb)

East Florida ESI Atlas (pdf, 97 kb)

Georgia ESI Atlas (pdf, 73 kb)

Each atlas contains a lengthy introduction that explains the methods used to acquire, synthesize, and map all the ESI information as well as a detailed listing of agencies to contact in the event of a spill. The maps themselves consist of three main types of information:

Shoreline Classification—a relative sensitivity ranking, on a scale from 1 to 10, based on a number of factors such as relative exposure to wave and tidal energy, shoreline slope, substrate type, biological productivity, and difficulty of cleanup activities. An ESI ranking of 1 represents a shoreline least sensitive to oil, while an ESI ranking of 10, represents a shoreline most sensitive to oil. Each ESI ranking is represented by a different color on an ESI map, giving quick reference to the shoreline's ranking. This provides responders with an idea of which shorelines need to be protected with the highest priority and which shorelines may be easier to clean after oiling.

Biological Resources—oil-sensitive animals and habitats such as the Least Tern and saltmarshes. Information on biological resources is very detailed including; seasonality, threatened/endangered status, activity, and relative concentration.

Human-Use Resources—specific areas, such as water intakes, recreational beaches, and archaeological sites, which have added sensitivity and value because of their cultural significance or use by humans.