Climatic change may have detrimental effects on the coastal habitats of Puerto Rico due to reductions in rainfall, increase in sea levels, and changes in the hydrology of coastal wetlands. Due to these concerns, a ground water monitoring system was established in October 2008 to study the Guánica Dry Forest ground water dynamics. This study aims to understand the relationship between groundwater levels and tidal fluctuations, rainfall, ground water salinity, and temperature. The risk of salinization of freshwater coastal ephemeral ponds in the Guánica Dry Forest (where the threatened Puertorican Crested Toad reproduces) will also be evaluated. Furthermore, this investigation will establish the basis of a long-term study of groundwater dynamics in the littoral costal zone of the Guánica Dry Forest that could allow the assessment of the impacts of climate change in these sensitive habitats.National Science Foundation, HRD #0734826 and University of Puerto Rico, Central Administration and Río Piedras Campus