In the Caribbean, the mangrove oyster Crassostrea rhizophorae and the Atlantic pearl oyster Pinctada imbricata have been studied and farmed; however, oyster aquaculture remains undeveloped in Puerto Rico. This study investigates oyster spat collection in Culebra, Puerto Rico, where the local fishing community is engaged in oyster aquaculture as a supplemental income source, despite limited knowledge of local spawning dynamics. Spat collectors and environmental sensors were deployed at five coastal sites and at two different depths and sampled every two months. Temperature and salinity were measured continuously. Results revealed significant spatial and temporal variation in spat settlement for both species, indicating distinct high-abundance sites and spawning periods. There was also a significant effect of salinity and temperature in C. rhizophorae and P. imbricata abundance. Additional studies are needed to determine clearer trends in spat abundance for different collector depths and types of collectors used. These findings provide critical baseline information for the development of small-scale oyster aquaculture in Puerto Rico and contribute to improving cost-effective spat collection strategies for tropical oyster species across the Caribbean.