As part of a CIFRE thesis, conducted in collaboration between CEFE, UMR MARBEC, and SPYGEN, I will study the impact of habitat and anthropogenic activities on crustacean diversity along the French Mediterranean coast and overseas territories (Mayotte and Réunion). In order to obtain the most comprehensive inventory possible in a non-invasive manner, data was collected by filtering water containing DNA left by individuals in the environment, known as environmental DNA (eDNA). Metabarcoding of environmental DNA allows the species from which the eDNA was collected to be identified by comparing it to a database. To do this, a reference database will be created using DNA collected from museums and aquariums, using both conventional and innovative DNA extraction techniques, such as capture. In addition, for reference databases with significant gaps, such as those for Mayotte and Réunion, artificial intelligence will be used to simulate the missing sequences. The primary objective of these inventories is to establish an initial inventory of crustacean communities in the Mediterranean, in line with the expectations of the National Biodiversity Strategy 2030 and useful for coastal monitoring and conservation. In addition, analyzing the impact of human activities on these dynamics could serve as a tool in sustainable resource management policies for crustaceans, a taxon that is often understudied.