This research aims to determine the ecosystems connectivity by observing the distribution of inter-island mangrove propagules in the territorial waters of Biawak Island. The data used are wind, tidal, and bathymetry of 2018. They are modeled according to the propagules’ weight and the particle trajectory module. The results showed that the entire propagules (Rhizopora sp, Sonneratia sp, and Brugueira sp) dominantly moved to the west and southeast. They are carried by the currents that are influenced by the west and east monsoon. The propagules of Rhizopora sp moves from east to southeast, Sonneratia sp moves from east to south, and propagules Brugueira sp moves from west to north. In addition to oceanographic factors, other parameters that can influence the pattern of propagules movement is the propagule’s mass; the lighter it is, the easier it is to be carried away.