If you like to spend time on Ibiza’s beaches, chances are you’ve come across a very special kind of plant, but perhaps without knowing what it is. The long brown strands that adorn the shoreline and the balls of fibre that blow about on the sand like tumbleweeds are not, as many people think, a seaweed invasion, but rather fragments of one of the island’s secret weapons: a type of seagrass called Posidonia oceanica. The patchwork of meadows that stretches between Ibiza and Formentera is responsible for keeping the waters around the islands crystal clear. They filter the water, absorbing carbon dioxide – lots of it – and releasing oxygen back into the atmosphere. It’s not for nothing that Posidonia is nicknamed “the lungs of the Mediterranean”.
Teeming with marine life, the meadows are vital to the local ecosystem. They are also a key brake against coastal erosion; the mounds of dead grass on the shores in winter are actually put there on purpose by the local authorities to stop the sand from washing away.
However, the plant is being decimated by human activity, namely pollution and boats. Just one vessel dropping anchor in a patch of grass can destroy within seconds an area that then takes centuries to regenerate.
DID YOU KNOW?
Posidonia oceanica is one of the world’s largest and oldest living organisms.
The meadows around Ibiza and Formentera are a UNESCO World Heritage Site.
Algunas secciones miden hasta 15 km de largo y tienen entre 80.000 y 100.000 años de antigüedad.
One hectare of seagrass can absorb 15 times more CO2 than a similar area of Amazon rainforest.
About half the oxygen we breathe is produced by the plant.
A third of the meadows in the western Mediterranean have been lost in the past 40 years.
Posidonia grows extremely slowly, at just 1cm per year.
HOW YOU CAN HELP
Use chemical-free sunscreen when swimming so as not to contaminate the water with harmful pollutants.
On boat trips, ask the captain not to anchor in the seagrass meadows. The free PosidoniaMaps app for iPhone and Android can help guide them.
Donate to IbizaPreservation to support our Posidonia protection work, helping fund scientific research, educational programmes, and awareness raising campaigns.
Find out more about IbizaPreservation’s work by going to ibizapreservation.org or following them on Instagram or Facebook @ibizapreservation.