Wildlife Damage Management, Internet Center for


Date of this Version

February 2001




Invasive alien species (IAS) are now acknowledged as one of the major threats to biodiversity, together with habitat loss and fragmentation. Furthermore, it is predicted that biotic invasions will become the major engines of ecological disintegration in the future; this is because of the increased spread of alien species, due to the greater mobility of the human population, rapidly growing transport technology, expanding tourism and travel activities, and world-wide free trade (Cox 1999, Ruesink et al. 1995).

In addition to the threats to biodiversity, the direct costs of IAS are immense. It is difficult to estimate precisely the economic losses caused by biotic invasions, including the impact of weeds on crop production, the increased costs of control, the decreased water supply, the management costs of reducing the alterations of protected areas, the impact of introduced pathogens affecting wildlife and public health, and the impact of marine organisms transported by ballast waters. However, the costs likely exceed tens of billions of Euros annually (GISP 2000).Therefore, the planning of more effective strategies to deal with biotic invasions is a conservation priority on a global scale. For this purpose, the implementation of new actions at a national, trans-border and international level are required, based on a proactive rather than reactive approach.

The need to prevent and control introductions and the severe threats posed by biotic invasions have been repeatedly addressed at an international and regional level (see Shine et al. 2000 for a review).

In the last decade, the World Conservation Union (IUCN) also made invasive species a primary focus for its global action; the Species Survival Commission, supported by the Invasive Species Specialist Group, recently produced the “Guidelines for the Prevention of Biodiversity Loss caused by Alien Invasive Species” (IUCN 2000). Furthermore, the IUCN is a major partner of the Global Invasive Species Project (GISP), a coalition of scientists, economists, lawyers, social scientists, conservation and resource managers working together since 1997 to develop a new comprehensive strategy, that will lay the groundwork for new tools in science, education and policy through collaborative international actions. According to decision V.8 of the last COP of the Convention of Biological Diversity (CBD), the GISP will assist the Executive Secretary in the implementation of art. 8(h) (see Box 1).