Monitoring Of The Artificial Reef Fish Assemblages Of The Marine Protected Areas Along The Alpes-Maritimes Coast (France, North-Western Mediterranean)

Artificial reefs have been deployed within the three marine protected areas located along the Alpes-Maritimes coast (Golfe-Juan, Roquebrune-Cap Martin, and Beaulieu-sur-Mer, France, North-Western Mediterranean). These protected and no-take areas - were created between 1980 and 1983. They have been fully protected since their establishment, except in 2004 when anthropic activities (except commercial fishing) were exceptionally authorized. Moreover, there have been no park rangers to prevent poaching since 2002.To carry out long-term monitoring of the marine organism mainly fish assemblages established in the artificial reefs, underwater visual censuses (UVC) were carried out in 1987/1989, 1998/2000, and 2008, according to a standardized method. All the fish species present on the artificial reefs were considered to assess density and biomass, but this method is time-consuming (divers formation to UVC techniques).In 2008, in addition to the traditional UVC, a new sampling procedure of the fish assemblages, the FAST method (Fish Assemblage Sampling Technique) was tested. With this method, sampling is based on the presence/absence of a number of given species. This list of species includes only species of interest for commercial and noncommercial fishing.A comparison of the UVC monitoring shows that density of the fish assemblages increased in the first 10 years, then did not increase during the last decade. These results can be explained by a lack of watching within the protected areas to prevent poaching since 2002 and to the reopening to the anthropic activities in 2004. The real efficiency of the artificial reefs to restore or sustain fish assemblages is then discussed.Finally, a comparison of the two census methods (UVC and FAST) has enabled us to put forward a simple, low-cost, and relevant protocol to regularly monitor the fish assemblages of the areas.