Abstract
Coral reef ecosystems are facing increasing pressures and disturbances, leading to a worldwide degradation of their status (e.g., recurring bleaching events). This situation generates an urgent need to improve methods used to study reef ecosystems and understand their resilience to different stressors. Such knowledge requires suitable andreliable data characterizing various physical characteristics of coastal waters.Remote sensing data is regularly used to monitor the evolution of living corals. Historical coral cover data issued from field surveys and hyperspectral aerial images, have been used over the reef platforms of Reunion Island to establish correlations with spectral indices computed from high and very high resolution satellite images (Pléiades, SPOT6/7, Sentinel-2). These results were validated in 2022 using newly acquired data, and allowed producing maps of coral covers over the reef platforms at different time periods. In this context, the use of the new Pléiades Neo (PNEO) imagery, with enhanced spatial and spectral resolutions, should help assess the potential such data offer toimprove coral distribution models and mapping.Another objective of this work was to evaluate the potential of the new PNEO Deep Blue band, in particular to retrieve information on deeper sea bottoms that are usually very difficult to access and poorly mapped.This report is organized into three sections. After a short presentation of the data used, we:- i). make a simple visual analysis in comparison with other reference data,- ii). evaluate the potential of the Deep Blue band for coral and seafloor mapping,- iii). use PNEO data to assess coral covers over Reunion’s reef flats.