Recent research has found that underwater seagrass collects up to 900 million plastic items in the Mediterranean Sea each year. Seagrass is vital in collecting and purging plastic waste into what are known as Neptune Balls. These balls of plastic pollution form naturally as the seagrass collects and traps plastics before releasing them in clumps, some of which wash back to shore.
The study, which was published in Scientific Reports was lead by Anna Sanchez-Vidal, a marine biologist at the University of Barcelona. In a statement, Sanchez-Vidal confirmed the findings, saying that they have proved the extent to which seagrass can trap plastic waste.
“We show that plastic debris in the seafloor can be trapped in seagrass remains, eventually leaving the marine environment through beaching,” Sanchez-Vidal told AFP.
The findings of this study now add yet another benefit of seagrass. Seagrass has long been known to balance its ecosystem. The seagrass absorbs carbon dioxide and releases oxygen into the water, improving the water quality in the process. Further, it plays the role of a natural nursery for hundreds of species of fish, and seagrass is the foundation of the coastal food web.
The research team has only studied the building up of plastic within seagrass in the Mediterranean Sea. In 2018 and 2019, the scientists managed to count the number of plastic bits found in Neptune balls that had been washed to the shore in Mallorca, Spain. They found plastic debris in half of the loose grass leaf samples collected, with a kilogram of the grass found to contain approximately 600 pieces of plastic. As for the denser balls of seagrass, only 17% of the samples collected were found to contain plastic. However, the balls had plastic at a higher density, with nearly 1,500 plastic bits per kilogram of Neptune ball.
Using the findings, the researchers were able to estimate the amount of plastic collected by seagrass in the Mediterranean. The good news is that the grass can help collect plastic waste. But researchers aren’t sure where all of the waste goes. The only waste that has been traced includes the Neptune balls and loose grasses that remain stuck on the beach.
“We don’t know where they travel,” Sanchez-Vidal said. “We only know that some of them are beached during storms.”
Via The Guardian
Image via Paul Asman and Jill Lenoble