EICAT is the IUCN Standard for the classification of impacts of alien taxa on the environment. It is a simple, objective and transparent method that classifies alien taxa into one of five impact categories, according to the magnitude of the detrimental impacts on native biodiversity.

Each of these five impact categories represents a different impact magnitude, depending on the level of biological organisation of the native biota impacted (individual, population or community) and the reversibility of this impact.

The scheme can be applied at a national, regional and global level: all EICAT assessments undertaken at the global level will be made available through the IUCN’s Global Invasive Species Database.

EICAT has the following five objectives: (i) identify alien taxa by levels of environmental impact, (ii) compare the level of impact by alien taxa among regions and taxonomic groups, (iii) facilitate predictions of potential future impacts of taxa in the target region and elsewhere, (iv) aid the prioritisation of management actions, and (v) facilitate the evaluation of management methods. EICAT is used by scientists, environmental managers and conservation practitioners as a tool to gain a better understanding of the magnitude of impacts caused by different alien taxa, to alert relevant stakeholders to the possible consequences of the arrival of certain alien taxa, and to inform the prioritisation, implementation and evaluation of management policies and actions.

It must be emphasised at the outset that EICAT is not a risk assessment, and its output alone should not be used to prioritise management actions for alien taxa.

EICAT must be applied in a consistent and comparable manner when assessing the impacts of different alien taxa, and therefore the EICAT Categories and Criteria should be used to inform the assessment process. There is also a separate accompanying Guidelines document that provides additional guidance to support the application of the EICAT Categories and Criteria, including on how to deal with uncertainty, the required documentation standards, and the full EICAT assessment process.

The EICAT Authority is the governing body co-ordinating the overall EICAT assessment process. The EICAT Authority comprises of individuals who may have remits relating to specific taxonomic groups or geographic regions. Most members of the EICAT Authority are members of the IUCN Invasive Species Specialist Group, but they may also be members of other SSC specialist groups, independent networks or other organisations.

The roles and responsibilities of the EICAT Authority include:

• Coordinating the EICAT assessment process
• Carrying out EICAT assessments
• Ensuring that at least one independent Reviewer who was not an Assessor or Contributor for an EICAT assessment agrees with the outcomes of that assessment
• Reviewing EICAT assessments
• Ensuring that all required supporting documentation is submitted with an EICAT assessment

The Chair of the EICAT Authority is nominated by the Chair of the IUCN SSC Invasive Species Specialist Group, and acts as the overseer and co-ordinator for official IUCN EICAT activities. The Chair acts as the point of contact for the submission of EICAT assessments, and for interactions, between the EICAT Authority, EICAT Unit and other IUCN structures, including the IUCN Red List Committee (that oversees the analogous Red List of Threatened Species process), other SSC Specialist Groups, and the office of the Chair of the Species Survival Committee.

The roles and responsibilities of the EICAT Authority Chair include:

• Initiating the consistency checking process of EICAT assessments submitted
• Overseeing the reviewing process of EICAT assessments
• Delegating the processes to other members of the EICAT Authority
• Final acceptance of EICAT assessments following the formal review process.

Current members of the EICAT Authority are:

Sabrina Kumschick, EICAT Authority Chair, Centre for Invasion Biology, Stellenbosch University and South African National Biodiversity Institute, South Africa

Piero Genovesi, Chair of the IUCN SSC ISSG, Institute for Environmental Protection and Research, Italy

Ana Novoa, Institute of Botany, Czech Academy of Sciences, Průhonice, Czech Republic

Anna Probert, University of Fribourg, Switzerland

Belinda Gallardo, Instituto Pirenaico de Ecología (IPE), CSIC, Spain

Bella Galil, Tel Aviv University, Israel

Cristina Preda, Department of Natural Sciences, Ovidius University of Constanta, Romania

Elena Tricarico, Department of Biology, University of Florence, Italy

Giovanni Vimercati, University of Fribourg, Switzerland

Giuseppe Brundu, Department of Agricultural Sciences, University of Sassari, Italy

Jan Pergl, Institute of Botany, Czech Academy of Sciences, Průhonice, Czech Republic

John Measey, Centre for Invasion Biology, Institute of Biodiversity, Yunnan University, China and Stellenbosch University, South Africa

Jonathan Jeschke, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) and Freie Universität Berlin, Germany

Katharina Lapin, Austrian Research Centre for Forests, Vienna, Austria

Maarten de Groot, Department of Forest Protection, Slovenian Forestry Institute, Slovenia

Montserrat Vilà, Estación Biológica de Doñana (EBD-CSIC) and University of Sevilla, Sevilla, Spain

Pablo González-Moreno, Department of Forest Engineering, ERSAF, University of Cordoba

Petr Pyšek, Institute of Botany, Czech Academy of Sciences, Průhonice and Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic

Sandro Bertolino, Department of Life Sciences and Systems Biology, University of Turin, Italy

Sven Bacher, University of Fribourg, Switzerland

Thomas Evans, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) and Freie Universität Berlin, Germany

Tim M. Blackburn, Centre for Biodiversity and Environment Research, University College London and Institute of Zoology, Zoological Society of London, UK

Wolfgang Rabitsch, Environment Agency Austria, Vienna, Austria