Using Environmental Sensitivity Index (ESI) maps and data can help oil spill responders and planners identify vulnerable coastal locations, so that they can establish protection priorities and identify cleanup strategies before a spill happens.

The 2026 ESI Guidelines (Version 5.0) is an in-depth report that summarizes the ESI methodology and how ESI maps and data are being developed and distributed using GIS technology.

Primary objectives of the report are to outline:

• Basic elements of a sensitivity mapping system
• The role shoreline type plays in the persistence and cleanup of spilled oil
• The ties between shoreline habitats and biological occurrences
• The ESI shoreline classification scheme and how it is applied
• Collection and synthesis of biological and human-use data
• The data structure for a digital ESI product
• Guidance on QA/QC of the ESI data
• Standard symbology to be shown on soft- and hard- copy maps
• Metadata requirements and standards

Version 5 reflects a number of modifications to the Guidelines. See the Appendix H for a summary of changes from Version 4.

The most current species list is available from the ESI Species List webpage.

View or Download the Current Guidelines: ESI Guidelines Version 5, 2026
 

Previous versions of the guidelines:

Version 4, published in 2019 [PDF, 27 MB]
Version 3, published in 2002 [PDF, 5.2 MB]
Version 2, published in 1997 [PDF, 544 KB]

Questions: Contact us with your questions, comments, or suggestions for the ESI Guidelines.