For millennia, the Posidonia Oceanica (Better known as the Mediterranean Posidonia or Neptune grass) has several uses for humans: in addition to being antibacterial and antifungal, this aquatic flower is also used as isolates for buildings. However, its usefulness does not stop there.
According to a 2021 study published in the journal Nature, the researchers explain that mattes, the name given to the thick tangle of their rhizomes, their roots and sediments, are a precious natural filter, cleaning the water of our coastlines. Thus, each year, organic matter balls called “equagropiles” would eliminate around 900 million plastic fragments: an ally of size therefore to cope with the pollution of the oceans, details Popular Mechanics in an article.
“There is solid evidence that the seabed constitute a final well for plastics of terrestrial originwrite the authors of the study. There is also evidence that part of the plastics on shallow seabed is rejected on the coast. ” The sea herbaria hold the plastic debris thanks to their natural fibers, which are then ejected from the plant and rejected on the ribs in the form of balls, thus contributing to “counter marine plastic pollution». These very dense “sea balls” sometimes run out of hundreds on the beaches.
To do this, the posidonia creates a real submarine meadow that can grow on rocky or sandy bottoms, and helps purify water more than 40 meters deep. Its creeping stems form a root system capturing pollutants – generally present in the waters of the rivers which pour into the Mediterranean – and trap them. The shoots then detach from the plant and form balls which end up reaching the shore, taking with them what they absorbed.
Hygienic towels, wipes or pads
The study specifically analyzed balls found in Mallorca, Spain. If only 17% of them contained microplastics, they contained in large quantities. The more compact the balls, the more likely they were to have caught plastic.
“”After the publication of our articletold BBC Anna Sanchez-Vidal, the main author of the Barcelona study, Many people started sending me photos of giant Neptune grass balls. Sometimes they contained hygienic towels, pads, wipes – objects containing a lot of cellulose, which flow to the bottom.»»
Up to 1,470 plastic elements per kilogram of plant material can be trapped in these “Neptune balls”. But plastic is not the only element absorbed by the plant which also captures carbon, trapping it and preventing it from reaching the atmosphere.
For Anna Sanchez-Vidal, these balls have a meaning not to be taken lightly: “It is a way for the sea to restore us waste that was not supposed to be at the bottom of the ocean.”
