Box 17.1 The Environmental Impact Classification for Alien Taxa
(EICAT)
EICAT is a simple, objective and transparent method to classify alien taxa
according to the magnitude of environmental impacts caused in their introduced ranges (Blackburn et al. 2014; Hawkins et al. 2015). It assesses impacts
caused by a specific alien taxon (mostly a species) on native species in the
recipient area and can help identify taxa with different levels of impacts as well
as facilitate comparisons of impacts between taxa and regions. Based on
published records of impacts, EICAT classifies detrimental impacts based on
12 mechanisms, namely:
• Competition
• Predation
• Hybridisation
• Transmission of diseases
• Parasitism
• Poisoning/toxicity
• Bio-fouling
• Grazing/herbivory/browsing
• Chemical, physical or structural impact on ecosystem
• Interaction with other taxa
Furthermore, if records of impact are available, EICAT distinguishes
between five impact levels based on the organisational level of the species
affected, as follows:
Minimal Concern (MC)—the alien taxon does not affect the performance of
any native species it interacts with through any of the above mentioned
mechanisms
Minor (MN)—the alien taxon affects the performance of at least one native
species through any of the above mentioned mechanisms, but does not
affect population size
Moderate (MO)—the alien taxon reduces the population size of at least one
native species through any of the above mentioned mechanisms, but the
native species is still present in the community
Major (MR)—the alien taxon leads to the local or metapopulation extinction
of at least one native species changing the native community, with the
impacts being reversible when the alien taxon is no longer present
Massive (MV)—irreversible community changes caused by the alien taxon
through the local, sub-population or global extinction of at least one native
species
If no data on impacts of the taxon in the alien range is available, it is
classified as Data Deficient (DD).
(continued)
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(EICAT)
EICAT is a simple, objective and transparent method to classify alien taxa
according to the magnitude of environmental impacts caused in their introduced ranges (Blackburn et al. 2014; Hawkins et al. 2015). It assesses impacts
caused by a specific alien taxon (mostly a species) on native species in the
recipient area and can help identify taxa with different levels of impacts as well
as facilitate comparisons of impacts between taxa and regions. Based on
published records of impacts, EICAT classifies detrimental impacts based on
12 mechanisms, namely:
• Competition
• Predation
• Hybridisation
• Transmission of diseases
• Parasitism
• Poisoning/toxicity
• Bio-fouling
• Grazing/herbivory/browsing
• Chemical, physical or structural impact on ecosystem
• Interaction with other taxa
Furthermore, if records of impact are available, EICAT distinguishes
between five impact levels based on the organisational level of the species
affected, as follows:
Minimal Concern (MC)—the alien taxon does not affect the performance of
any native species it interacts with through any of the above mentioned
mechanisms
Minor (MN)—the alien taxon affects the performance of at least one native
species through any of the above mentioned mechanisms, but does not
affect population size
Moderate (MO)—the alien taxon reduces the population size of at least one
native species through any of the above mentioned mechanisms, but the
native species is still present in the community
Major (MR)—the alien taxon leads to the local or metapopulation extinction
of at least one native species changing the native community, with the
impacts being reversible when the alien taxon is no longer present
Massive (MV)—irreversible community changes caused by the alien taxon
through the local, sub-population or global extinction of at least one native
species
If no data on impacts of the taxon in the alien range is available, it is
classified as Data Deficient (DD).
(continued)
492
T. A. Zengeya et al.