by Lauren Tam
Recently, I had a class debate on the question: “Should we ban plastic water bottles?”. One argument made was that plastic is a huge factor in marine life destruction. Plastics, specifically microplastics, are detrimental to the health of marine ecosystems. In 2010, Scientists speculate that 4.8 to 12.7 million metric tons entered the ocean. As a result, we need to make bigger improvements to plastic waste management. However, can we find a natural way to filter out these foreign items?
A recent study found that underwater seagrass appears to trap plastic pollution in natural bundles of seagrass fibre, named “Neptune balls”. Without any human intervention, these plants can accumulate almost 900,000,000 plastic items in the Mediterranean alone each year. Anna Sanchez-Vidal, lead author and marine biologist at the University of Barcelona says, “As plastic debris in the seafloor is trapped in seagrass remains, they will eventually leave the water through beaching.”
The Importance of Seagrass
This newfound ability adds to the extensive list of functions that seagrass offers. Underwater seagrass is crucial to absorbing CO2 and releasing oxygen; in addition, it is a natural habitat for a variety of aquatic species. Additionally, it provides stabilization to the sea bottom, and it can even help support local economies. However, it is unknown if collecting plastic actually damages the seagrass itself. Sanchez-Vidal and her team studied a species found only within the Mediterranean sea, called Posidonia oceanica. In both 2018 and 2019, they counted the number of plastic particles found in sea balls. These sea balls washed up on four beaches in Mallorca, Spain. The researchers discovered up to 600 bits of plastic per kilograms of leaves.
Only 17% of the tightly bundled seagrass fibre known as Neptune balls, contained plastic. However, it was at a much greater density, almost 1,500 pieces per kilogram of seaball! The researchers used estimates of seagrass fibre production within the Mediterranean to estimate how much plastic might be filtered within the entire basin. The Neptune balls form from torn leaf bases that remain attached to the stems, called rhizomes. Slowly buried by sediments, the leaves form stiff fibres that create a ball, collecting plastic pieces in the process. This new discovery may be the key to improving our plastic waste management.
How Can We Help?
There are simple things we can do to prevent plastic from entering the oceans. To help, we can avoid products with microbeads such as hand sanitizers, face scrubs, and shower cleansers. We can join beach clean-ups and recycle soft plastics at stores like London Drugs. And, we can use reusable grocery bags, containers, and water bottles. These are some examples of what we can do, but it is only a start. After all, it is better to have a billion people doing something imperfectly, than a million people doing it perfectly.