Dataset on physical-chemical and marine water quality variables in San Andrés Island, Colombian Caribbean

In situ measurements and laboratory analysis considering i) marine water quality measurements, ii) Physical, chemical, and heavy metals characteristics of desalination brine, and iii) Conductivity- Temperature-Depth (CTD) profiles, were conducted. For marine water quality, the data collection aimed to evaluate the distribution of salinity, temperature, and heavy metals both at the surface and close to the seabed and other water quality parameters at specific locations. For salinity and temperature, a salinity tester model HQ40d was used. Moreover, marine water and brine samples were collected and analyzed in a laboratory for multiple parameters, including heavy metals such as Cr and Cu, and the alkaline metal ion Mg. The data indicated that greater salinity levels are at the bottom and closer to the brine discharge point. As for temperature, lower values are prevalent near the bottom, while higher values are present at the water surface. Last, Conductivity–Temperature–Depth (CTD) profiles showed variation along the water column in salinity and temperature, especially close to the brine discharge. This dataset can potentially be useful for researchers, policymakers, and locals to raise awareness through data, modeling, and solutions for the water quality conditions under a brine and wastewater discharge on an island.