Invasive Species Impact

Invasive species — organisms introduced (intentionally or accidentally) outside their native range, where they spread and cause ecological or economic harm — are the second-largest driver of species extinction globally. Without natural predators, parasites, or diseases that control their populations in their native range, invasive species can dominate new ecosystems and cause cascading ecological collapse. Notorious examples: cane toads (introduced to Australia 1935 to control beetles, now 200 million strong and poisoning native predators); kudzu vine ('the vine that ate the South,' covering 3 million acres in the southeastern US); rabbits in Australia (24 introduced in 1859, responsible for the extinction of multiple native species); brown tree snake in Guam (accidentally introduced post-WWII, responsible for exterminating 12 of 22 native forest bird species); zebra mussels in the Great Lakes (filtering phytoplankton that supports the food chain). Cost of invasive species to the US economy: $120 billion annually.