ABSTRACT
One of the most important roles for citizen scientists is acting as sentinels and reporting ad hoc encounters with a targeted species. The citizen science project can be more effective at intercepting invasive species than professional survey work. As sentinels, citizen scientists have the potential to contribute to Early Detection provided effective links are developed between citizen scientists and those able to intercept and remove problem species or the citizens themselves are provided with the information and training to enable them to undertake the role. Most of the citizen science projects described involve people observing and reporting from their own local area. This is extremely valuable as those people will be familiar with the area prior to the arrival of a new species, may visit an area regularly and will be ideally placed to notice and report on any changes which may occur – including new or unusual species.
