The researchers found that underwater seagrasses in coastal areas trap plastic pollution in a group of natural fibers known as the “Neptune Balls”.
Without human assistance, the swaying plant, anchored to the shallow seabed, could collect nearly 900 million pieces of plastic in the Mediterranean alone every year, the study reports in the journal Scientific Reports.
“We showed that plastic debris in the seafloor can get trapped in the debris of the seagrass, eventually leaving the marine environment through the beach,”; said lead author Anna Sanchez-Vidal. A marine biologist from the University of Barcelona told AFP.
The cleanup “represents the continued removal of plastic debris from the ocean,” she added.
Further studies on the extensive list of services that seagrasses provide – for oceanic ecosystems and for humans living near the water’s edge. They play an important role in improving water quality, absorbing CO2 and emitting oxygen, and provide a natural nursery and refuge for hundreds of fish species. It is also the foundation of the coastal dietary fiber.
By anchoring in shallow water, it prevents beach erosion and mitigates the effects of devastating storms.
There are 70 species of seagrass in the sea, which are grouped into many flowering families. Originally on land, colonies of the ocean were formed from 80 m to 100 m.
Growing from the Arctic to the tropics, most species have long, grass-like leaves that can create vast underwater meadows.
It is not clear if collecting plastic will damage the seagrass.
To better understand the seagrass aggregation ability Sanchez-Vidal And her team studied organisms found only in the Mediterranean. Posidonia oceanica.
In 2018 and 2019, they counted the number of plastic particles found in seabirds lapping on four beaches in Mallorca, Spain, where large seagrass plains are offshore.
Half of the plastic debris contained in the loose seagrass specimen was 600 bits per kilogram of leaf.
Only 17% of the more densely packed seagrass called Neptune balls contain plastic. But there is a much higher density – almost 1,500 pieces per kilogram of seabirds.
By estimating seagrass fiber production in the Mediterranean, the researchers estimated the amount of plastic that might be leachable in the entire basin.
Oval ball – the shape of a rugby ball – a pattern from the base of the leaf destroyed by the action of ocean currents. But still attached to the stem called rhizome
As they are slowly buried by precipitation, the damaged leaf cladding forms stiff fibers that become tangled in balls, keeping the plastic in the process.
“We don’t know where they traveled,” Sanchez-Vidal said. “We only know some of them were stranded in the storm.”
In 2018, WWF forecasts that within weeks during the holiday season in the Mediterranean Sea, an increase in marine pollution made of plastic contributes to about 150 million tons of plastic in the ocean.