IAS beyond the Habitats Directive: a momentum for further EU harmonization?

Invasive alien species (IAS) were already described as a threat to biodiversity at the time the Habitats Directive was adopted, in May 1992. Various international treaties, amongst which the 1979 Bern ¹ and Bonn ² Conventions, but also the 1982 Montego Bay Convention, ³ had previously stressed the need to address the impact of ‘non-native’ or ‘exotic’ species on indigenous fauna and flora. The issue was already mentioned in the Birds Directive. ⁴ It was already high on the agenda of the IUCN. ⁵ It was also on the negotiating programme of the Rio Convention on Biodiversity, leading to the adoption of a provision inviting Parties ‘as far as possible and as appropriate, to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species’. ⁶