DAISIE - Alien species invasions

The biodiversity of Europe is under the threat of a number of alien species invasions. These invasions are often the result of human actions, given that introductions of invasive species are linked both to international mobility and trade. Some threatening species are brought intentionally, such as pets or ornamental plants, while other are imported through trade. Globalisation has many benefits but dramatically increases the number of entry points for new species in Europe.

The amount of invasive alien species (IAS) has significantly risen in the past years and now stands for a major cause of biodiversity loss: environmental impacts are considerable. These range from subtle ecological modifications to massive changes at ecosystem scale. This can lead to the near extinction of native species such as the European mink (Mustela lutreola) which is threatened by the American mink (Mustela vison). Another huge impact is represented by the potential hybridisation which can arise between native and invasive species. Such an hybridisation has already occurred between the white-headed duck (Oxyura leucocephala) and the introduced ruddy duck (Oxyura jamaicensis) for instance.

IAS are also a major economic concern. According to the recent Assessment of the impacts of IAS in Europe and the EU (June 2008), the damage and control cost of IAS adds up to € 12 billion each year in Europe. These costs encompass the damages in agriculture, forestry, fisheries and aquaculture. It is assumed that these costs are much higher in reality; given that the former estimation takes only into account already existing data whereas many countries have just began an approach for identifying the costs towards IAS.
Moreover, IAS are a societal concern as they can affect human health by conveying diseases or causing allergies. The common ragweed for instance (Ambrosia artemisiifolia) can trigger asthma and hay fever.

Although many European countries have tackled the issue of alien invasions for protecting their domestic ecosystems, a global approach is required to overcome the inefficiency of fragmented measures.
The LIFE programme has already allocated over € 38 million since 1992 to support more than 180 projects dealing with the problem of IAS. In order to address this environmental issue, a three-step approach is carried out according to the guiding principles of the Convention on Biological Diversity (CBD). The guidance consists of (i) the prevention of IAS introductions between and within states, which is far more environmentally preferable and cost-effective than taking measures once IAS are established , (ii) the early detection and rapid action towards the eradication of detected IAS and (iii), the containment and long-term control when eradication is not achievable.

The dissemination of information regarding IAS is of paramount importance to prevent alien species from settling in Europe. A number of regional and Europeans institutions and organisations have provided datasets about alien species causing impacts on health, economic activities and biodiversity. These include:

  • the European and Mediterranean Plant Protection Organisation (EPPO),
  • the North European and Baltic Network on Invasive Alien Species (NOBANIS) which provides a database of both current and potential invasive species,
  • the initiative Streamlining European 2010 Biodiversity indicators (SEBI 2010), led by the European Environment Agency (EEA), which aims at compiling a set of indicators towards halting biodiversity loss as well as establishing a list of 168 IAS,
  • the DAISIE project (Delivering Alien Invasive Species Inventories for Europe) which identifies the 100 worst European invaders and creates a database of all alien species in Europe.


Natura 2000 – Number 25 – December 2008