Since 2008, the Invasive Species Early Detection (ISED) Program of the Eastern Rivers and Mountains Network (ERMN) has surveyed for and detected incipient populations of invasive plants, animals, and diseases in ERMN parks. Early detection of invasive species followed by rapid response can detect and eradicate incipient populations before they have a chance to become widely established; thus eliminating the need for costly and resource-intensive control programs. While long-term changes associated with established invasive species are being monitored through other protocols, the ISED program focuses on new populations of invasive species early in their invasion. Only when invasions are caught early will the chance of eradication remain high. Known ecological impacts of invasive species include loss of threatened and endangered species, altered structure and composition of terrestrial and aquatic communities, and reduction in overall species diversity.