Changes in the hydrochemistry of a karstic lake in Yucatan, Mexico

The Yucatan Peninsula is a karstic region with groundwater-dependent ecosystems and geological features such as karstic lakes. The objective of this research was to calculate the volume of water stored in this section of the aquifer and to describe the changes in the hydrochemistry of the lake Punta Laguna as a representative of karstic lakes in the Yucatan Peninsula. A bathymetry and calculation of the volume of water stored in the lake resulted in 5,198,505 m 3 with a maximum depth measured of 26.6 m Physicochemical measurements were completed in surface and three vertical profiles to estimate the mass of nutrients and ions and to describe the current hydrochemistry. The lake is an oligotrophic one of mixed-typed water (chloride-calcium/magnesium), saturated or supersaturated with calcite, dolomite and aragonite due to limestone dissolution. No evidence obtain regarding the saline intrusion. The conclusion that we can derive from the data is that Punta Laguna is a tropical karstic lake in good condition with low anthropogenic influence, evolving hydrochemically speaking. The changes over a 20-year period suggest that there has been reverse ion exchange, evaporation and sulfate reduction.