Many alien taxa are known to cause socio-economic impacts by affecting the different constituents of human well-being (security; material and immaterial assets; health; social, spiritual and cultural relations; freedom of choice and action). Attempts to quantify socio-economic impacts in monetary terms are unlikely to provide a useful basis for evaluating and comparing impacts of alien taxa because they are notoriously difficult to measure and important aspects of human well-being are...

Alien species can exert negative environmental and socio-economic impacts. Often it is not clear which of the numerous alien species are most important in terms of damage, and therefore, impact scoring systems have been developed to allow a comparison and thus prioritization of species. Here, the Generic Impact Scoring System (GISS) is presented, which relies on published evidence of environmental and socio-economic impact of alien species.