Background The American bullfrog (Lithobates catesbeianus) and the African clawed frog (Xenopus laevis) are two invasive amphibian species that have been introduced to France, elsewhere in Europe and to other continents. They are a major threat for wetlands because of their disruptive impact on autochtonous communities (competition, predation, transmission of pathogens) and their strong colonisation capacity (high productivity and high dispersal). In France, the American bullfrog can be found in Gironde, Bassin d’Arcachon and Dordogne (Aquitaine), and Sologne (Centre), while the African clawed frog is present in a single area straddling two departments, Deux-Sèvres and Maine-et-Loire. Some populations are monitored and controlled, but there is no coordination at national level and insufficient sharing of resources and know-how. Furthermore, there is no methodology for identifying the appropriate control strategy for each species. The African clawed frog is listed as an Invasive Alien Species of Union Concern. Objectives The LIFE CROAA project aims to completely eradicate the American bullfrog from 29 sites in Sologne and eight sites in Gironde and to significantly reduce the population of this invasive alien species (IAS) in Dordogne as a precursor to total eradication post-LIFE. At Bassin d’Arcachon, where the number of colonised sites is unknown, the project plans to prevent the American bullfrog population expanding. It also aims to limit the expansion of the African clawed frog along dispersal corridors. Other specific project objectives are as follows: To develop a methodology for selecting control strategies for invasive populations of amphibians when the size of the colonised area impedes eradication (e.g. African clawed frog in Deux-Sèvres/Maine-et-Loire and American bullfrog in Gironde); To prevent novel introductions by identifying major pathways for alien amphibians and by raising awareness among stakeholders involved in the trade and exchange of animals; and To create an early detection and assessment system for the introduction of alien amphibians thanks to a network of local stakeholders (local population, authorities, pet shops, laboratories using alien species and amateur enthusiasts), the development of a mapping tool and the expertise of IAS managers. The project actions targeting IAS will contribute to the EU Biodiversity Strategy to 2020 and the implementation of EU Regulation on IAS. The project team will attend pet trade shows and provide training to those responsible for ensuring compliance with agreements on alien species. The aim is to assist the French government in strengthening and implementing EU regulation. Expected results: The project expects to achieve the following results: Development of a model for selecting the optimal control strategy for an invasive population of amphibians; Demonstration of new capture methods that are 20% more efficient; The eradication or significant reduction of small populations of American bullfrog; Raised awareness of alien amphibians among the main pet shop chains, laboratories, pet frog and toad owners and nature NGOs; The creation of a network of trappers across the range of the African clawed frog, extending from the Deux-Sèvres into areas where the impact of the population must be sharply reduced; and The creation of a network of observers (both professionals and volunteers) willing to operate an early detection and assessment system for alien amphibians. The expertise developed by the project team and networking with other groups of experts on freshwater ecosystems will strengthen the capacity to assess novel threats and to propose appropriate national responses to IAS.