Alien Species Can Wreak Havoc

Humans are the most mobile of species and can live anywhere on earth. When they travel from place to place they often transport other species along with them, resulting in alien introductions. While the most drastic devastation occurs on small islands, large landmasses have also felt the impact of imported species that have no natural control to their numbers.

Prior to the arrival of humans, Hawaii had thousands of species of birds, and invertebrates, and plants found no where else on earth. Since the introduction of mongoose, rats, pigs and dogs and – as well as many species of plants, -- over half the bird species and countless species of snail have gone extinct. The introduction of rabbits into Australia, Asian fish species into Florida, Africanized bees into Brazil, plants such as Kudzu, melaleuca, and Brazilian pepper throughout the US, and rhododendrons into England are obvious examples of introduced species that outcompete and exterminate the native animals and plants.

Green crabs, zebra mussels, the African tulip tree and the brown tree snake are just a few of the ecological offenders named invasive alien species. Biological invasion by alien species, second only to habitat loss as a threat to biodiversity, severely disrupts freshwater and marine ecosystems, tropical, boreal and temperate forests, urban areas, islands, grasslands and deserts. This in turn impacts global and local economies. Introductions of alien species can happen deliberately or unintentionally, for example, by organisms “hitch-hiking” in containers, ships, cars or soil.