Year 2009

Causes and impacts of invasive alien species

Globalization has resulted in greater trade, transport, travel and tourism, all of which can facilitate the introduction and spread of species that are not native to an area. If a new habitat is similar enough to a species’ native habitat, it may survive and reproduce. For a species to become invasive, it must successfully out-compete native organisms for food and habitat, spread through its new environment, increase its population and harm ecosystems in its introduced range.

Most countries are grappling with complex and costly invasive species problems. For example, the annual environmental losses caused by introduced pests in the United States, United Kingdom, Australia, South Africa, India and Brazil have been calculated at over US$ 100 billion (CBD, 2006). Addressing the problem of invasive alien species is urgent because the threat is growing daily, and the economic and environmental impacts are severe.