Resumen:
Critical as they are for humans and nature, freshwater ecosystems are threatened-but the extent and depth of these threats are not well understood, especially if essential biodiversity data are lacking. Any policy aimed at protecting such ecosystems must first
assess the threat factors and the potential harm, well before proposing conservation measures such as the creation and development of Protected Areas (PAs). These assessments must be done using a deep and sound knowledge of the actual and potential biodiversity variables. Freshwater ecosystems have been largely neglected in traditional PA design and management (Abell et al. 2007), be it for scarcity of biodiversity data, or for more perception-related reasons such as visibility and accessibility driving the allocation of conservation resources to more data-rich environments.