Seagrass Naturally Cleans the Sea

Underwater Seagrass may be trapping millions of pieces of tiny marine plastic in natural balls of fiber in what is known as Neptune balls. Huge meadows of seagrass make up most of the coastal waters around the world and when there are storms these balls are washed to the shores according to New Science.

Seagrass meadows – there are 70 different species of sea grass around the globe –  provide important ecosystem benefits including improving water quality, absorbing CO2, mitigating climate change, as well as providing a habitat for many species. Now ocean pollution  cleanup can be added to the list.

The fact that these grasses contained plastic particles was discovered by Anna Sanchez-Vidal, lead author and a marine biologist at the University of Barcelona in Spain and her team who have been measuring the amount of plastic that was collected from seagrass from four beaches in Mallorca, Spain between 2018 and 2019.

The researchers studied just one species, Posidonia oceanica, and found plastic debris in half of the 42 Neptune balls they examined and it amounted to 613 microplastic items per kilogram of leaves. They estimated that up to 867 million plastic items, mostly filaments, fibers, and fragments of polymers, may be trapped in the seagrass in the Mediterranean Sea every year, according to the research that was published in the January 2021 issue of the journal Scientific Reports.

“We show that plastic debris in the seafloor can be trapped in seagrass remains, eventually leaving the marine environment through beaching,” Sanchez-Vidal, told the Agence France-Presse (published in The Guardian). This plastic cleanup, “represents a continuous purge of plastic debris out of the sea,” she said.

Around 8 million tons of plastic pollution end up in the world’s oceans yearly according to IUCN and make up 80 percent of all marine debris. Plastic pollution is threatening food safety, health, tourism, and contributes to climate change.

“This is why we need to protect and preserve these vulnerable ecosystems. However, the best environmental protection strategy to keep oceans free of plastic is to reduce landfills, an action that requires to limit its use by the population,” the researchers concluded in the study.

While at this time, more research is needed to see if other species of seagrass also trap plastic in their leaves. Seagrass could become a powerful  tool in the battle against plastic in our oceans and seas.