According to the World Conservation Union, invasive alien species are the second most significant threat to biodiversity, after habitat loss. Most introduced species do not become permanently established in their new environment, and of those that do, most never become a problem. However, the odd introduction thrives and flourishes in their new location, and out-competes native plants and animals for food, water and space. The impact of these invasives on native ecosystems, is severe and often irreversible, and can cost billions of euro each year.
