This work consisted of making  CTD measurements on the coasts of Isla Mujeres, as well as in the lagoons called "las salinas". The main objective was to have records of temperature and salinity of the Isla Mujeres water bodies . So measurements were made with a Castaway Sontek CTD with a total of 68 measurements. The names of these lagoons "Las salinas" are; Laguna Makax and Salina Chica. The information was analyzed statistically and maps were made in geographic information systems QGIS. The results were that  “Las salinas” found salinity levels between 4.6 PSU and 12 PSU. The Makax lagoon is the body of water that registered higher salinity values ​​(38.23 PSU on average) due to its proximity to the sea. The salinity of the sea that surrounds Isla Mujeres is 35.48 PSU on average.