Some alien species can co-exist in their new environment without impacting negatively on native species. However, other alien species become invasive and their impact can be ecologically devastating and lead to the extinction of native species as they are out-competed by or preyed on by invasive species. Invasive species have been introduced into new environments both intentionally and accidentally.
The Invasive Species Specialist Group (ISSG) is a global network of scientific and policy experts on invasive species. Organized by the IUCN Species Survival Commission, the ISSG aims to reduce threats to natural ecosystems and the native species they contain by increasing awareness of invasive alien species and ways to prevent, control or eradicate them.