Coastal and Marine Ecological Classification Standard

The Coastal and Marine Ecological Classification Standard (CMECS) provides a comprehensive national framework for organizing information about coasts and oceans and their living systems. This information includes the physical, biological, and chemical data that are collectively used to define coastal and marine ecosystems.

CMECS is designed for use within all waters ranging from the head of tide to the limits of the exclusive economic zone, and from the spray zone to the deep ocean. It is compatible with many existing upland and wetland classification standards and can be used with most if not all data collection technologies. These characteristics allow scientists to more easily use and compare data from various sources and time frames.

Frequently Asked Questions

One-Page CMECS Description

CMECS Structure

CMECS classifies the environment into biogeographic and aquatic settings that are differentiated by features influencing the distribution of organisms, and by salinity, tidal zone, and proximity to the coast. Within these systems are four underlying components that describe different aspects of the seascape. These components provide a structured way to organize information and a standard terminology. The components can be mapped independently or combined as needed. 

The Sample Unit Gallery provides examples of various sites and how they would be classified using CMECS units. Each example shows a large-scale, ground view of the site with a location map and smaller-scale images to provide landscape context where appropriate. Additional samples will be added in the future. Users are encouraged to provide their examples to the CMECS Implementation Group.

In combination, the setting and component units can be used to identify biotopes, which are unique ecological units with biotic and abiotic elements.

The CMECS classification of settings and components that describe the seascape.

Examples of Components

CMECS Catalog of Units

CMECS users can now search an online database of units by keyword, or browse to view each unit within a component. This database has been completed for the biogeographic and aquatic settings; the water column, geoform, substrate, and biotic components; and for all the modifiers. New units will be added to this database periodically as part of the routine update process.

Additional Information

CMECS was approved by the Federal Geographic Data Committee (FGDC) in August 2012. The standard was developed, tested, and distributed for peer review over a period of several years by the NOAA Office for Coastal Management, NatureServe, NOAA Office of Habitat Conservation, U.S. Environmental Protection Agency, and U.S. Geological Survey. As an FGDC standard, federally funded projects working with environmental data in the coastal zone should use CMECS as their primary classification system or include CMECS attributes for their data.

Since CMECS was endorsed as a dynamic content standard, it will be revised periodically using new scientific information and feedback from users. See the CMECS Maintenance section below to learn more about this process and how to provide input.

Technical Resources

The documents in this section contain recommendations but not requirements. They are “living documents” that may be modified or retired according to changes in technology and the standard itself.

Geodatabase Data Model Proposed CMECS Data Structure – A short outline of how CMECS data could be organized in an Esri file geodatabase structure.

Coding Approach and Code Set – Spreadsheets with the code set for the entire CMECS system and a short document explaining how the codes can be applied as attributes for observations and mapping.

Classifiers Document – Document that presents the physical, chemical, and biological characteristics necessary to assign CMECS unit labels to data. This is of value to those collecting source data that will later be used to develop CMECS habitat maps.

Nomenclature Document – Several examples of how CMECS unit names from several components can be compiled into terminology for CMECS-derived units.

CMECS Concept Map – A graphical representation of the CMECS component framework and hierarchical structure. Useful for understanding how the components relate to each other and which ones might be appropriate for specific projects.

Oregon Estuary Inventory

  • Oregon Estuary Viewer – An example of how CMECS is being used for estuary data at the state level.
  • CMECS GIS Process Methods – Description of the methods used by the project team in the generation of Oregon estuary CMECS products.


This online map shows and allows users to explore the geographic distribution of CMECS projects, which have been organized into the categories below:

  • Mapping Projects – Projects where source data were analyzed or interpreted directly to produce CMECS data from the outset.
  • Data Integration Projects – Projects where several existing data were integrated to produce a seamless map or establish historical trends.
  • Crosswalks – Projects where existing or new data classified under another system were translated to CMECS.
  • Programmatic Implementation – Projects where CMECS is the organizing framework for multiple smaller-scale efforts and data sets.

Users are encouraged to contact these groups to learn how CMECS contributed to their goals and the specific approaches they took.

Publications –

  • Allee, R., J. Kurtz, R. Gould, D. Ko, M. Finkbeiner, and K. Goodin. 2014. “Application of the Coastal and Marine Ecological Classification Standard Using Satellite-Derived and Modeled Data Products for Pelagic Habitats in the Northern Gulf of Mexico.” Ocean and Coastal Management. Volume 88. Pages 13 to 20.
  • Cochrane, G.R., M.E. Dethier, T.O. Hodson, K.K. Kull, N.E. Golden, A.C. Ritchie, C. Moegling, and R.E. Pacunski. 2015. “Salish Map Series—Admiralty Inlet, Washington.” U.S. Geological Survey. Open-File Report 2015-1037. Page 34.

CMECS Maintenance

CMECS has been designed to be a dynamic content standard; that is, it will be periodically updated to reflect the best science and the needs of the coastal management communities. The framework of a dynamic standard process has been developed to receive input from researchers and users of the standard and to accomplish modifications to CMECS. While many aspects of this process are still being developed, the process has, and will continue to have, these standard characteristics:

  • Clear criteria and requirements for proposing and evaluating a change to CMECS
  • The involvement of subject-matter experts when needed to ensure scientific validity of any change
  • NatureServe
  • Different levels of review depending on the scale of the proposed change
  • Feedback loops to proposers and reviewers
  • The ability to track and maintain lineage between old and new versions of CMECS
  • A decision-dissemination element to share the results

The CMECS Partnership

CMECS is the result of an ongoing collaboration among several organizations. The principal partners of the standard are listed here:

  • NOAA’s National Marine Fisheries Service
    • Office of Habitat Conservation
    • Office of Science and Technology
  • NOAA’s National Ocean Service
    • National Centers for Coastal Ocean Science, Biogeography Branch
    • National Coastal Data Development Center, National Centers for Environmental Information
    • National Marine Sanctuaries
    • Office for Coastal Management
    • Office for Coastal Management, National Estuarine Research Reserve System
  • NOAA’s Office of Oceanic and Atmospheric Research
  • NatureServe
  • U.S. Environmental Protection Agency
  • U.S. Geological Survey, National Wetland Research Center
  • University of Rhode Island

Contact Information

For technical assistance, general guidance, or to offer suggestions contact us at