How big a threat do invasive alien species pose to European biodiversity? A ranking of species for urgent risk assessment
Invasive alien species (IAS) pose a threat to native European biodiversity and cost the EU annual damages worth EUR 12 billion as a result of IAS effects on human health, damaged infrastructure, and agricultural losses1. IAS are the focus of Target 9 of the Convention of Biological Diversity (CBD) and Target 5 of the EU Biodiversity Strategy: By 2020, IAS and their pathways are identified and prioritised pathways are managed to prevent the introduction and establishment of new IAS. The EU framework for action against IAS is set out in a Regulation2 adopted in 2014. This provides for the adoption of a list of IAS of Union concern that will be subject to restrictions across the EU. The first step in order to consider a species for listing is to undertake a risk assessment.