Background The archipelagos of Frioul and Rioul close to the city of Marseille are home to breeding colonies of three species of marine bird that are of Community interest: Cory’s shearwater (Calonectris diomedea), Yelkoun shearwater (Puffinus yelkouan) Mediterranean storm petrel (Hydrobates pelagicus melitensis) and Mediterranean shag (Phalacrocorax aristotelis desmaresti). As a result of the availability of food in and around Marseille, the yellow-legged gull nesting population (more than 15 000 pairs) has greatly increased to the detriment of other nesting species. Moreover, the spread of gull has favoured the development of opportunistic plants and supported the population increase of introduced species like black rats and rabbits, and thus contributing to the impoverishment of the islands’ biodiversity. The populations of migratory birds and nesting birds must cohabit with the black rat and the wild rabbit, which destroy eggs, attack puffin chicks and adults, and occupy the reproduction sites (cracks, faults of the rocks and burrows) of the birds. As a result, sites used in the past by storm petrels on the Riou archipelago have been abandoned, as well as some of the former colonies of Cory’s shearwater. On the archipelago of Frioul, the breeding colonies of Cory’s shearwater remain threatened and show low reproductive rates. Moreover, since the 1930s, the number of tourists and the amount of human activity related to the proximity of the town of Marseilles has increased, resulting in strong disturbances to the ecosystem of these islands. Objectives The general objective of the project was to assure the conservation of the protected marine bird colonies and to put in place favourable conditions for the return of birds to former sites. Notably through acquiring data collected on the ground, the project would evaluate the specific threats and progress of the project actions, monitor breeding sites in littoral cliffs and follow-up the reproduction success of the species, study the diet of the protected species, and discover new nesting sites as well as new colonies. Such information would be analysed in order to install nesting boxes in existing colonies and position devices that emit birdsong to attract new nesting couples. Data would also be used for the implementation of programmes to partially exterminate rats and rabbits on the large islands and totally eradicate them on the small islands. The project also proposed to limit the human disturbance on the breeding colonies thanks to a network of paths to channel the tourists and to surveillance and public education (booklets, exposition, web site, slide shows, etc.). Moreover, regulation of users and the reinforcement of legal protection would also be set up within the framework of this project. The experiences and results obtained would be shared with another LIFE project for the puffins on the island of Hyères. From the studies, an overall picture of the state of populations of the bird species and conservation problems in the region could be obtained. Results The project resulted in an improved knowledge of the populations of the endangered marine bird species. It also evaluated threats and drew up a document for reinforcing legal protection of the islands’ Maritime Park. Other key results included: The complete eradication of the black rats on the Plane Island and density reduction of rats and rabbits on the bigger islands (Riou, Pomègues et Ratonneau); Increase on the overall number of individuals of the targeted marine birds, its reproductive success and new occupied nesting sites as well as immediate and lasting installation of birds in the artificial nesting boxes (especially the occupancy by Yelkoun shearwater); The use of an innovative device for diffusing birdsong to attract storm petrel and establish new colonies sites (though effectiveness is not shown yet). The installation and restoration of paths to support the tranquillity of the colonies; The realisation of communication tools and especially a book on the management of the populations of marine birds of the islands of Marseille; The transfer of the results through a network set up on the small islands of the Mediterranean.The project also alerted to decision-makers to the need for conservation, helping ensure the continuation of the actions. The management structure will continue to implement the actions developed in the framework of the project as outlined in the management plan drawn up for the two archipelagos (2006/2011 on the Frioul archipelago and 2009/2014 for the National Natural Reserve of the Rioul archipelago), and the document of objectives 2008/2013 of the Natura 2000 site. Disclaimer : This « results » section should be considered as a draft until the Commission has completed its evaluation .