Almost daily, we can read newspaper articles voicing concerns about alien species and their impacts on native biodiversity,
economic resources, and human health. Alien or non-native species introductions by humans rank as one of the two top factors (after habitat loss) leading to declines in biological diversity . Their synergistic effects with changes in land-use and climate may lead to even more severe declines in the future . Globally, there is a sense of urgency for practical steps to be taken to strictly identify and control the introduction of alien species and manage species that have already become invasive ,.
Although scientists and policymakers are becoming increasingly aware that introductions of alien species impose serious impacts ,, there are large differences in how nations deal with the issue. While some
countries have detailed lists of alien species and well-
established protocols for their trade and control, information in other countries is almost non-existent. Once established in a small area, species can enlarge their range across wide geographical areas, sometimes rapidly, so tackling the problem requires a strategic approach involving cooperation of many countries. Efforts to come to grips with this problem led to The Global Invasive Species Programme (GISP) .