Understanding the population structure of Atrina Vexillum, giant bivalves, in French polynesia
Résumé
Atrina vexillum is a native bivalve in French Polynesia. Limited knowledge exists in the scientific literature, especially regarding the connectivity of its populations. The insular context of Polynesia poses an additional barrier to larval dissemination and, consequently, the resilience of local populations. My PhD aims to provide the first data on the demography, connectivity and habitat of these populations. Initially, different populations were identified and then characterized in terms of size, age, and proximity to each other over a year on five islands, revealing over 2600 individuals. Ecosystems specific to their development were also identified. These initial findings highlight the geographical proximity of the species to certain pressures, particularly anthropogenic, emphasizing the importance of effective species protection, considering its decline described by the local population. A study using the analysis of 30 microsatellite markers is underway to examine the population structure across the Society Islands through genetic connectivity and the building of a pedigree. These data could be used for environmental management. A preliminary study indicates very low connectivity between two islands separated by only 50 km. This work aligns with the Polynesian government's initiative to protect its biodiversity.