Posidonia in Menorca is a marine plant that forms large meadows under the water, and it is the reason the sea around the island is so clear. I’ll tell you what it is, why it needs protecting and how we look after it on our boat trips.
In short:
- Posidonia is a plant, not a seaweed, and it only grows in the Mediterranean.
- It cleans the water, produces oxygen, protects beaches from erosion and shelters huge numbers of fish.
- In the Balearic Islands it is forbidden to anchor on posidonia. We always anchor on sand.
What posidonia is
Posidonia oceanica, also called Neptune grass, is a marine plant with roots, leaves and flowers that only lives in the Mediterranean. It forms meadows on shallow seabeds and grows very slowly: a meadow can take centuries to form.
From the boat it is easy to spot: it is the dark patches on the seabed, between the light sand.
Why posidonia matters so much in Menorca
- Clear water: it filters the water and holds the sand on the seabed. That is why the coves of Menorca have that colour.
- Oxygen: it produces oxygen and absorbs CO₂.
- It protects the beaches: it slows down the waves, and the dry leaves that wash up on the shore protect the sand in winter.
- Marine life: it is home to fish, octopus, starfish and seahorses. Without posidonia there would be much less to see when snorkelling in Menorca.
What puts it at risk
Pollution, building work on the coast and, above all, boat anchors. An anchor that drops onto a meadow and drags pulls up plants that took decades to grow. That is why anchoring on posidonia is forbidden in the Balearic Islands.
How we look after it on our trips
- We always anchor on sand, never on the meadow. That is why we sometimes stop a little further from the shore.
- Zero waste: everything that comes on board goes back to port.
- We explain on board what posidonia is and how to recognise it, and we ask guests not to touch or disturb the animals.
- We sail slowly close to the coast and inside the coves.
Frequently asked questions
Is posidonia a seaweed?
No. It is a marine plant, with roots, leaves, flowers and fruit.
Why are there posidonia leaves on some beaches?
They are dry leaves the sea leaves on the shore in autumn and winter. They protect the sand from storms, so it is better not to remove them.
Can you anchor on posidonia in Menorca?
No. It is forbidden in the Balearic Islands. You have to anchor on sand or use mooring buoys.
Where is the best place to see posidonia?
Snorkelling in the coves of the south coast or around Isla del Aire, when the water is calm.
What happens if it is windy on the day of the trip?
We go to the most sheltered coast. We check the AEMET marine forecast every morning.
If you want to see the posidonia meadows of Menorca with a skipper who respects them, have a look at our south coast and north coast routes, the available dates for the Karnic SL601 and the Beneteau Flyer 7, or write to us on WhatsApp.
