In this paper we present the assessment of the main threats to beach ecosystems arising from their use in San Andrés, a small oceanic island in the Caribbean. To determine each threat and its pressure level on the ecosystem, we applied surveys and, based on social cartography methods, we obtained perception maps with relative threat magnitudes for each use, from very low to very high. The results suggest that the current economic model of San Andrés, almost totally dependent on massive tourism, may increase pressure intensities to the beach ecosystems due to increased pollution, urban development, land reclamation and exploitation of coastal resources. Tourists, the motor and benefiiaries of this socio-ecosystem, may be affected by these tensors, discouraging them to visit again the island. It is recommended to include in the island´s management plans new legislations to minimize the impacts of beach use on this ecosystem.