Plastic and its Effects on the Coral’s Appetite
Richard Vevers, from the documentary Chasing Corals, said “Most people stare up into space with wonder, yet we have this almost alien world on our own planet, just teeming with life. It’s a world completely out of sight and out of mind.” Earth has so much we can learn from, yet we have been making an increasingly negative impact on it. It is estimated that there are 8 million tons of plastic added to the ocean each year, and when we think of plastic, we think of it in relatively large pieces. But the ocean is full of microplastics, which affects all marine life, from seabirds to coral.
Corals almost look as if they are the decorations of the sea, just to be stared at and admired while snorkeling, but corals have a life of their own. Each individual coral body is called a polyp, and polyps are all animals that collectively make a large coral. The tentacles have cells that can be filled with venom. Corals have stomachs and mouths, and the regular diet of a coral includes phytoplankton and small fish. Corals are already undergoing bleaching due to climate change; and at Duke University, it recently was found that corals have been consuming microplastics. Alexander Seymour, one of the researchers said that, “This is just another drop in the bucket among the very large challenges faced by these species.” We don’t have enough information to know exactly why they like it, but it is definite that the plastic is not having good effects on the digestive systems of corals.
Graduates Austin Allen and Alexander Seymour suspected that the corals might think that these plastics are food, because there might be chemicals in them that appeal to the corals. They conducted their experiment in North Carolina by taking corals from the sea and then introducing different types of plastic to see which one the corals preferred. The options were plastic without additional bacteria or plastic that had been put in seawater and had a biofilm of bacteria. It was found that the corals consumed more of the plain plastic, possibly because the microbes on the second plastic were harder for the corals to eat quickly. Since the corals don’t have eyes, they use chemosensors, or their version of a tongue to see if they want to eat the plastic. The Washington Post stated, “If the sand came near their mouths, the animals used tiny hairs covering their body to brush themselves clean. But if a piece of plastic tumbled by, the corals snapped into action. They fired cellular harpoon guns, called cnidoblasts, which launched toxic barbs into the plastic particle. The corals scooped the plastic towards their mouths with their tentacles, then gobbled up the trash.” Since various other sea creatures are attracted to coral, Seymour said, “We need to be thinking about the taste of plastic as a paradigm, not just a problem for corals.”
There is so much plastic in the ocean (approximately 5.25 trillion individual pieces), and the amounts are rapidly increasing. But what people don’t understand is that plastic doesn’t break down, it breaks up; and unless we can find a way to break it down without having negative effects on the world, we need to reduce our usage of plastic. Some simple ways to start decreasing your plastic waste are by using reusable water bottles, bags, products without microbeads, and staying away from products with plastic packaging. Plastic has become such an important material in our lives, so it is hard to eliminate it at first, but if we all make an effort, that is what will help prevent more problems.