The clear turquoise waters of our beautiful beaches are renowned throughout the world. Yet few people know that much of this beauty is due to the Posidonia Oceanica, an underwater grass that has been called "the lungs of the Mediterranean". Named after Poseidon, the Greek god of the sea, this "super plant" is the most widespread sea grass in the Mediterranean. It grows in tightly packed underground meadows that can stretch hundreds of kilometres in length. It has lived for more than 100,000 years – making it one of the oldest organisms on Earth – and has been recognised by UNESCO as a World Heritage.

We are fortunate that this massive underwater plant lines the seabed between Ibiza and Formentera, because it is incredibly effective at filtering the seawater. This natural process is what keeps the waters around Ibiza and Formentera so pristine. But this amazing plant is also ecologically important to our planet, as it is extremely powerful in removing carbon dioxide from the air and producing oxygen. In fact, one square metre of Posidonia produces as much oxygen as an entire hectare of the Amazon rainforest. In addition to reducing carbon in the atmosphere, it also provides shelter for spawning fish and many other marine species. This plant is truly a gift from nature, but unfortunately it has been under attack from the effects of mass tourism. 

Despite EU legislation to protect the Posidonia, a combination of pollution, increased fishing activity and untreated sewage has caused great damage to this plant that is so important to the Mediterranean ecosystem. But one of the gravest threats comes from the ever-increasing number of boats that are here in the season. Not only do they cause harmful pollution, but their anchors rip through the Posidonia. The answer to this problem may be a phone app that uses digital technology, satellite location and Google Maps.

The app is called Posidonia Maps, and its main promoter is Manu San Félix, a marine biologist who founded the Vellmari diving school on Formentera. Manu is on a mission to save the Posidonia, and he has spent years working with his camera to create an underwater map of the meadows between Ibiza and Formentera. The way the app works is simple: When the captain of a boat is ready to drop anchor, he turns on the app which locates his boat and superimposes it on a map of the Posidonia. If it shows that the boat is over a meadow, then the captain will move to a different location before dropping anchor. The entire area around Ibiza and Formentera has already been mapped by Manu, and work has begun on the coast of Mallorca, which also has Posidonia meadows.

Manu is also working on a project called La Gran Pradera, which seeks to restore the posidonia meadows to their full strength. "For years, until boat anchoring in the Mediterranean was regulated, the posidonia were brutally destroyed. The good news is that they can recover." The goal is to fully repopulate 7,000 m2 of the Ses Salines Natural Park, and so far this volunteer program has planted over 10,000 new plants.

The protection of the Posidonia is essential to keeping our seas clean and full of life. The IbizaPreservation foundation takes an active role in this by supporting the Posidonia Maps app. They are also calling for a reduction in the number of vessels during the summer season, and improved treatment of the waste water that is discharged into the sea. Together with other organizations and the government they are working to save this natural treasure.