8. Invasive species

The cumulative number of alien species introduced has been constantly increasing since the 1900s  While the increase may be slowing down or levelling off for terrestrial and freshwater species, this is certainly not the case for marine and estuarine species. A relatively constant proportion of the alien species established cause significant damage to native biodiversity.

While the majority of the approximately 10 000 alien species recorded in Europe (DAISIE project) have not (yet) been found to have major impacts, some are highly invasive.

While invasive alien species are recognised as a major driver of biodiversity loss, the issue of 'alien species' may in the future need to be considered in the context of climate change and particularly adaptation.