Invasive Species

When an introduced species becomes invasive, the effects can be terrible. In the United States alone, invasive species cause more than $123 billion in damages per year. It has been estimated that over 68% of the organisms listed as threatened or endangered species by the International Union for the Conservation of Nature and Natural Resources have been classified as a result of invasive species. Over 50,000 of the 750,000 species in the United States are exotic. Approximately 5,000 of these are considered invasive. Because it is difficult to gather these data, these are probably underestimations of the actual effects of invasive species. Invasive species not only displace native flora and fauna, they homogenize existing ecosystems, greatly reducing the number of available biological resources.