The aliens are here!

Ever been abroad, perhaps to an exotic destination, and wanted to recreate the holiday environment at home, for instance by snatching a cutting from a beautiful flower and planting it in your garden? Please think twice, it might be a harmful visitor that could trigger an alien invasion with devastating impact on your local natural world. The EU, too, is concerned, and to protect biodiversity, environment ministers on 25 June adopted conclusions concerning the control and management of invasive alien species.

Warty comb jelly, Mnemiopsis sp., Monterey Aquarium
Photo: Wikimedia Commons

More than 11 000 non-native species are present in Europe. They are animals, plants and microorganisms that have succeeded in establishing themselves in a foreign habitat where they pose a threat to native species. Controlling invasive species and repairing the damage they cause, is estimated to cost at least 12 billion euro a year.

The relocation of new species may be intentional. Plants and animals are introduced for economic reasons: the Nile perch was introduced into Lake Victoria for aquaculture purposes, where it has contributed to the extinction of an estimated 200 native species.

International trade and transport facilitate accidental introduction. Non-native species hitch a ride on lorries, trains or in the ballast water in ships' hulls, which is how the warty comb jelly moved from its native Western Atlantic coast to the Black Sea, where it is suspected of playing a role in the dramatic drop in anchovy stocks. The parakeet population of Brussels parks are exotic pets that escaped or were released from captivity, and survived.

More information:
Council conclusions (pdf) 
Council webcast of press conference 
Invasive Alien Species - Commission website 
DAISIE (Delivering Alien Invasive Species Inventories for Europe - funded by the Commission) 
Global Invasive Species Database (note the "100 of the Worst" red button top right)