The Future of Bacteria Cleaning Our Plastic Waste

THE FUTURE OF BACTERIA CLEANING OUR PLASTIC WASTE BY ALLISON CHAN REVIEWING PROGRESS IN CLEANING PLASTIC-FILLED OCEANS USING NOVEL BIOLOGICAL METHODS E verything has a beginning and an end. An apple core thrown into the dirt can be consumed by a worm, which then excretes nutritious waste for new plants to grow on. However, man-made items such as plastics, styrofoam, rubber, and aluminum are defying this natural cycle that allows growth in our ecosystem. What happens to the plastic water bottle you might have used the last time you went hiking? While an apple can be recy- cled into new material within two months, a plastic bottle can take more than 400 years to decompose. Plastic waste chokes the normal cycles of our ecosystem, and it is critical to find ways to flush the durable material out without harming the environ- ment even more. While we may think of plastic as cheap, lightweight, and disposable, like our to-go package: plastic spoon, fork, contain- er, cup, and bag, it doesn’t just “disappear” after thrown away. Instead, much of it actually collects in the ocean. IN 2015, IT WAS ESTIMATED THAT MORE THAN 5 TRILLION PLASTIC PIECES WEIGHING OVER 268,940 TONS WERE AFLOAT AT SEA, not including the larger plastic debris. 4 How did it get there? One of the most common ways that marine debris trav- els from land to water is by being swept through storm drains during rain storms. Rivers and waterways also wash trash into the bay. While we do not see the supposed amount of used plastic on land, most of it collects in our oceans. Most critically, the plastic in the ocean endangers marine life because it is a choking hazard and toxic. Marine animals such as sea turtles, mammals, seabirds, and crustaceans are vulnerable to entanglement encounters, which can lead to mortality. Plastics, espe- cially polyvinyl chloride, or PVC, are toxic for our health and the environment. 9 PVC releases mercury, dioxins, and phthal- ates, which could lead to life-long health threats, such as cancer and damages to the immune or reproductive system. 3 Plastics take a long time to decompose- but what about biodegrad- able plastics? Contrary to what one might expect, BIODEGRADABLE PLASTICS MAY NOT ACTUALLY BIODEGRADE QUICKLY, due to the fact that most of it ends up in the ocean. Even in favorable environments, such as in the soil with bacteria, fungi, or hot temperatures, biodegradable plastic bags only half-decompose after 389 days. 2 Degradation of biodegradable plastics takes approximately 3 years underwater, since these biodegrading conditions differ from what we see on land. In addition, heavier plastics would not be able to break down by UV light if they sink. While there may be ways to remediate the harm done, sea debris continues to increase, making cleanup programs insufficient. FALL 2016 | Berkeley Scientific Journal