What's a Microplastic?   

By Emma Kropke

 A year, a month, a week, a day. Even an hour, a minute, or a second cannot pass without the average individual utilizing plastic. It has become ubiquitous in our everyday lives and continues to grow more essential within healthcare, the transportation industry, and household items. Plastics are extremely versatile, they possess a range of unique properties making them lightweight yet strong, functional at a wide range of temperatures, and resistant to corrosion and erosion (11). Not to mention, it has made products previously consisting of metal and traditionally more expensive materials substantially cheaper for both production companies and the consumer (1).

When talking about plastic in this light, one may think it’s the perfect solution and should be implemented in all applications of life. However, the drawbacks of plastic are extensive. The ingredients and unique material that make plastic what it is also forge a product that is difficult to recycle, a vessel for toxins, and forever lasting. Research done by Woods Hole Oceanographic Institution states that over 8 million metric tons of plastic end up in the ocean every year (13). To make matters even worse, the plastic that ends up in the ocean takes up to 500 years to degrade (14). Even then, generations and generations into the future, it doesn’t fully disappear. Plastic truly embodies the term forever – it just gets smaller and smaller, breaking down into what we call microplastic (8). Officially, any piece of plastic less than five millimeters in size, smaller than a grain of rice, is referred to as micro (8). Plastic debris can come in all shapes and sizes, but those tiny little specks of color you see scattered in the sand are coined “microplastics.”

Microplastics can be categorized as primary or secondary. Primary microplastics are plastic particles that enter our environment already micro in size (8). They can be found in cosmetics, as well as microfibers from clothing and other textiles, such as fishing nets (8). Secondary microplastics are particles that derive from the breakdown of larger plastic items, such as water bottles. This breakdown is caused by exposure to environmental factors, mainly the sun’s radiation and ocean waves (8). In a study published in March of 2023 by Marcus Eriksen, a marine biologist and co-founder of the 5 Gyre Institute, it was estimated that over 170 trillion plastic particles are afloat in the world’s oceans (6). 170 trillion. There are more plastic particles in our oceans than there are dollars in Bill Gates, Warren Buffet, Jeff Bezos, and Elon Musk’s pockets combined. And most of these plastic particles are, you guessed it, microplastic. If you’re sick of hearing that word by now, just know I’m sick of writing it. However, microplastics are a more important topic now than they ever have been and need to be discussed if we want to see a change. They are becoming an increasingly alarming issue for us humans, animals, and entire oceanic ecosystems.

Coastal ecosystems such as mangrove forests, seagrass beds, and coral reefs are vital components that keep our oceans healthy and functioning. Yet, microplastic infestation is disrupting the connectivity of these seascapes and diminishing their ecosystem services. Especially among our beloved reefs. Coral reefs, even though they cover less than 1% of our earth, support more the 25% of all marine life (4). Healthy coral reefs provide a habitat for feeding and mating to over one million aquatic species including important commercially harvested fish (3). Their 3D structure also breaks apart wave energy helping to protect coastal infrastructure from hurricanes, flooding, erosion, and storm surges (3). The white sand beaches, beautiful waterfront properties, magnificent snorkeling, and bountiful fishing we owe to our coral reefs. Unfortunately, our relationship with the reefs is not a symbiotic one. While they provide a myriad of benefits for us, we continue to threaten their existence by dumping metric tons of plastic into their home.

The coral reef food web doesn't end there. We too are a part of this ecosystem. The majority of human populations consume fish and many coastal communities are heavily reliant on seafood. However, seafood is one of the top three contributors to human consumption of microplastics (5). Just like any other predator-prey interaction, we can consume microplastics — especially when eating different types of shellfish (10). Foods that contain bivalve mollusks like grilled oysters, scallop ceviche, clam chowder, steamed mussels, you name it, can contain microplastics (2, 10). It is estimated that the average American citizen consumes over 50000 plastic particles per year due to diet and drinking water (5). Even worse, the World Wildlife Fund estimates that people can consume up to five grams of plastic a week (12). That’s the equivalent of a plastic credit card being consumed every week.

Although plastic may be the easier and cheaper option, there are  significant trade-offs. Its forever-lasting existence has diminished the health of our oceans and our reefs, threatening our livelihoods. As microplastics become more prevalent, it is important to understand how individual plastic consumption, plastic waste disposal, and plastic decomposition affect what’s valuable to us. Coral reef biota and humans are being infiltrated with microplastics causing negative health effects and potentially more unknown consequences. Microplastics are here to stay, threatening not only the ecosystem but the corals themselves. It may be the beginning of understanding what this all means, but there’s still time to dismantle the plastic pollution pipeline.

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