Drones over Sant Elm to help resolve the green sea puzzle. | P. Aguilo

At the start of July, the mayor of Andratx, Jaume Porsell, announced that there was to be a study into the incidence of planktonic algae that appears off Sant Elm in the summer. The cause of the green colour of the sea when the summer weather is at its hottest is said to be something of a mystery, and the town hall is now using drones to study the currents. These have been capturing data with which the dynamics of the currents can be determined. The town hall's environment department is using the data to create a thermal map of the sea water off Sant Elm.

The drones have been active when the temperatures are highest and so when there is greatest evidence of the planktonic algae, believed to be the reason for the green colour. Statistical photometry (measurement of light), sea temperature measurements and the inertia of currents will be combined in the overall analysis.