A new study, published in Scientific Reports, has found that roughly 900 million pieces of plastic can be filtered from the Mediterranean each year with “balls” made of shallow seaweed.
“We found that plastic debris on the seabed can stick to seaweed debris and then drift ashore, and ultimately escape from the marine environment,” said Anna Sanchez Vidal, a marine biologist at the University of Barcelona who led the study.
Seagrass fields play a number of roles in the ocean ecosystem: They play a major role in improving water quality, absorbing carbon dioxide, and providing shelter for hundreds of fish species. They also prevent coastal erosion and reduce the impact of destructive waves fueled by storms, according to the online edition of the British daily The Guardian.
To understand the process of collecting plastic trash, Sanchez Vidal and colleagues focused their study on a seaweed species, Posidonia oceanica, that lives exclusively in the Mediterranean.
Between 2018 and 2019, experts looked at how many pieces of plastic in bundles of seaweed washed ashore on the shores of Mallorca, called Neptune balls.
Half of the loose balls are found in a plastic trash can, about 600 pieces per kilogram of paper.
Only 17 percent of Toughened Packs discovered plastic, but in a much higher proportion: around 1,500 pieces per kilogram.
Based on all this, researchers estimate that approximately 900 million plastic waste from the Mediterranean could be filtered by grasslands each year. It is not known whether collecting plastic waste will harm seaweed.
Some rugby ball bundles drift ashore during storms.