Characterizing Connectivity Along the Kuroshio Current in an Artisanal Reef Fishery

Informed management in the face of rising anthropogenic pressure has become a priority for the sustainability of coastal fisheries in the Coral Triangle. Depauperate information on pelagic larval duration and behavior presents a particular challenge to understanding the scale of movement in many target coral reef species in this region. In such cases, genetic analyses can illuminate dispersal patterns. Schooling, planktivorous caesionids are reef-associated and heavily impacted by artisan fishing pressure. We collected samples of Caesio cuning from five localities in the apex of the Coral Triangle to examine genetic connectivity along ~2000km of the Kuroshio Current to the northern extent of the species’ range. We barcoded and genotyped individual samples via RAD tags and are using a panel of SNPs to examine (1) levels and direction of gene flow between and among sites in the Philippines and Japan and (2) whether significant decreases in effective population size (N_e) at the limits of the species’ range can be detected. Characterizing genetic signatures from sites proximal to strong ocean currents and from the core to the periphery of the species’ range provides us with a clearer understanding of connectivity in C. cuning, helping to inform optimal management strategy for this species.