Our Beautiful World
Why so much seaweed on the beaches here?
Seaweed depositions at the beach of Es Grau.
Posidonia oceanica (commonly known as Neptune Grass or Mediterranean tapeweed) is a seagrass species that is
endemic to the Mediterranean Sea. It forms large underwater meadows that are an important part of the ecosystem.
The fruit is free floating and known in Italy as 'the olive of the sea' (l'oliva di mare).
Balls of fibrous material from its foliage, known as egagropili, wash up to nearby shorelines.
On the beach there were a lot of those round things, made up by fiber of something.
We wondered from where it came.
We still do. But they were everywhere on the beach.
That's what we wrote when we were down there. Coming home we learned more.
The balls, or aegagropiles, are actually composed of the fibrous remains of Posidonia oceanica.
Over time, dead fibrous tissue of individuals of this species are tossed about by waves.
The constant rolling action of the sea eventually forms this material into balls which wash up on the beach.
The oceanic Posidonia is an endemic plant in the Mediterranean with roots, stalk, leaves and fruit that lives under water
between the surface and a maximum depth of some 40 metres.
The plant forms prairies of Posidonia, called also, seaweed fields,
although they are not formed by seaweed, that are the most important
ecosystem of the Mediterranean, equivalent to the forests of the
It is thought that in the Balearics and Pitiüses (Pine Islands,
south of Ibiza), there are some 750 km2 of prairies of Posidonia
Although the scientific community has recognised their importance
to maintain the quality of the coastal waters and to form
Finally, we stress that in 1993 the Unesco declared Menorca a Reserve
of the Biosphere because of the important archaeological