Atrina vexillum, a native bivalve species in French Polynesia, holds significant ecological importance due to its large size and its distribution across the Indo-Pacific Ocean. Additionally, this species is notable for its colonization of muddy habitats lacking other solid structures. Despite its potential significance, limited scientific literature exists on this species, particularly concerning population connectivity. The insular context of French Polynesia presents challenges for larval dispersal, potentially impacting the resilience of local populations. The primary objective of my research is to investigate the demography, connectivity, and habitat characteristics of Atrina vexillum populations. During a year, we identified and characterized populations on five islands, revealing over 2600 individuals. This involved assessing size, age, and spatial proximity, and identifying crucial ecosystems for their development. Preliminary findings highlight the geographic proximity of Atrina vexillum populations to various pressures, notably anthropogenic influences, emphasizing the urgent need for effective conservation measures given reported declines in local populations reported by residents. This research proposes a way for policymakers to safeguard potentially ecologically significant elements within the environment, even before fully determining and quantifying their impact, by prioritizing some populations and reinforcing local action over other approaches. In pursuit of this goal, my research involves genetic analysis using 30 microsatellite markers (SSRs) to study population structure and connectivity across the Society Islands. Initial results from this genetic investigation reveal low connectivity between populations on islands separated by just 30 km. These comprehensive data sets and ongoing analyses have significant implications for environmental management strategies aimed at conserving and protecting Atrina vexillum and its associated ecosystems. By providing clues on the demography, connectivity, and habitat preferences of Atrina vexillum, this research contributes valuable insights that can inform evidence-based conservation policies and management practices in French Polynesia. Moreover, this study serves to fill critical gaps in our understanding of local bivalve populations, advancing our knowledge of connectivity dynamics in marine ecosystems.