In the Spring of 2019, I was fortunate to be studying abroad in the Galápagos. During one of our data-collection trips, my classmates and I snorkeled by the islands of Cuatro Hermanos near the island of Isabela. I had initially separated from the group to explore and freedive the deep vertical drop-off on the Western side of one of the small islands. I was lucky to encounter a school of pelican barracuda, a yellowfin tuna, and even a pair of scalloped hammerheads as they cruised by at about 20m depth along the seawall. I then turned around and headed back to my fellow students to find out what they had seen in the shallow water cave I had seen them swim towards before I left. As I reached them, a green sea turtle glided out of the underwater portion of the cave. It was swimming awkwardly, inefficiently, and closer inspection revealed a fishing rope tied around its forward right limb. I made several dives with my knife in hand to cut the rope, but the turtle was reluctant to let me get close and eventually swam off. Even in the famed Galápagos Marine Park, the effects of bycatch were evident.
Inspired by this unfortunate encounter, I decided to do a deep dive into ocean plastic pollution. The invention of plastic transformed the global economy. It was a malleable, easy to produce synthetic compound with an infinite number of applications from packaging and household object-making to the creation of machinery and tools. The issue with plastic comes with its lifetime; plastic compounds take thousands of years to degrade. The most startling fact I came across during my research was that every piece of plastic ever made still exists today. Once generated and used, 12% ends up incinerated and 79% in natural environments (landfills or the ocean). Only 9% is recycled (Geyer et al, 2017).
Plastic enters the ocean primarily from major rivers in underdeveloped Asian and African countries: the Indus, Ganges, Yangtze, Yellow, Hai He, Pearl Amur, Mekong, Nile, and the Niger (Schmidt et al, 2017). Due to a lack of recycling plants and support from governments, trash is often dumped freely into these rivers and allowed to pass through into the ocean. Once in the sea the plastic floats and is carried by oceanic currents and eventually concentrates within ocean gyres: massive systems of circular currents formed by the Earth’s rotation and wind patterns. There are five ocean gyres: in the Indian Ocean, North Atlantic, South Atlantic, North Pacific, and South Pacific. You may know the North Pacific Gyre as its more notable name—the Great Pacific Garbage Patch. Eriksen et al, 2014 estimated there are at least 5.25 trillion particles of plastic weighing 268,940 tons in the world’s oceans. And a more recent study done by Lebreton et al, 2018 estimated nearly half of the debris was comprised of fishing nets—much like the one that nearly drowned the green sea turtle in the Galápagos.
In order to prevent ocean plastic pollution, I firmly believe that change must occur on the political and corporate level. Individual decisions to invest in plastic alternatives certainly helps but is not a practical and scalable solution when considering the sheer size of the global plastic economy.
