The sand in the Mexican Caribbean is made from finely ground particles of coral and cal-careous algae (a type of seaweed). The most common calcareous algae found in our sand are known as Halimeda. There are many varieties of calcareous algae, but Halimeda is easy to recognize.
This small green plant is approximately 8” – 12” long when alive, and is frequently seen floating on the surface or washed up on the shore. There are numerous small bead -like segments con-nected together which sometimes gives the appearance of a necklace. Halimeda was given the common name “Sea Garland” back in 1640 by Parkinson. As the Sea Garland dies and changes colors, the small segments gradually turn white, fragment, and disburse as powder between the grains of sand. In this way, as much as 30% of the sand’s composition becomes a fine white organic powder, compliments of Halimeda.
Over hundreds of thousands of years, the corals and the Halimeda have laid down their lives to gradually build our famous beaches.
The result is the fine white powdered sand that we so much enjoy today. As you walk on the beaches at Sereno, you will notice that the sand never gets hot, even under the midday summer sun. Say thanks to Halimeda, which does not absorb the heat. Have fun on our beaches!