UTOPIAN - Identifcation of priority conservation areas on the reef flats of Reunion Island - 2021 - 2022 activity report ; UTOPIAN - Identification des zones d'enjeux prioritaires de conservation au sein des platiers récifaux de l'île de La Réunion - Bilan d'activité 2021-2022 ; UTOPIAN - Identifcation of priority conservation areas on the reef flats of Reunion Island - 2021 - 2022 activity report: Case study of the Saint-Pierre reef complex ; UTOPIAN - Identification des zones d'enjeux prioritaires de conservation au sein des platiers récifaux de l'île de La Réunion - Bilan d'activité 2021-2022: Étude de cas sur le complexe récifal de Saint-Pierre

The various permanent monitoring networks on Réunion show that the dynamics of benthic and ichthyofaunal populations are in a state of decline. These various monitoring networks allow diachronic monitoring using so-called "sentinel" stations, but the high spatial heterogeneity of biotic populations cannot be reflected by such monitoring. Spatial approaches have been developed through specific programmes, such as habitat mapping and the acquisition of hyperspectral satellite imagery. Therefore, to build on what already exists and to go further in spatialising priority conservation issues and areas of vulnerability, this study explored for the first time the potential of the COral Reef Rapid Assessment Method to meet management and governance needs. The Saint-Pierre-Terre-Sainte epi-reef complex in the south of Réunion was surveyed using 786 circular plot and 164 random patch. Within each circular plot, eight ecological variables were estimated visually within a 100m² circle. The mobile fauna was estimated by random patch of 2x10 minutes within a 50x50m square station according to four ecological variables. All these station data were interpolated using the ordinary kriging method. In this way, each collected variable was spatialised. The spatial distribution of the ecological indicators was discussed in the light of the spatial distribution of the abiotic variables. In addition, these spatialisations were compared with data obtained from monitoring using more traditional methods such as the Line Intersect Transect or the Belt Transect. Finally, intra-annual monitoring was carried out at 30 fixed points on 2 different sites (Colimaçons and Cap Champagne) to study the sensitivity of the proposed composite indicators to seasonal variations. At the end of this first year of study, the conclusions are favourable for the use of the CORRAM method, coupled with geostatistical tools, to spatialise a set of ecological and abiotic variables. The interpolation results give values comparable to those of the sentinel stations ...