Forget giant pandas displaced by deforestation, or carbon-spewing Chinese sneaker factories. The latest environmental outrage is about good old-fashioned trash.
Scientists have known about the Great Pacific Garbage Patch, sometimes called the “trash vortex,” since 1998. An oceanographer taking a shortcut from Hawaii to Los Angeles found that in the Pacific Ocean, in the calm waters north of the Hawaiian islands, the trash that makes it out to sea is held in place by the winds and currents that frame the area. They outline a circular patch in the ocean called the North Pacific Gyre, where the garbage accumulates in an area that’s been estimated to be as big as the size of Texas at minimum, but potentially as large as the entire United States.
An Invisible Island
The world produces about 260 million tons of plastic every year, and only 5 percent of that is recycled. Eighty percent of the trash in the oceans is composed of plastic, and although some trash is spilled (or dumped) from ships, the overwhelming majority comes from those of us who live on land. When someone in China or Seattle uses a trash bag or a plastic bottle and doesn’t dispose of it properly, it gets washed down the sewer and out to sea with the other wastewater, where currents carry it to the northern Pacific. Some experts estimate that the garbage patch contains one hundred million tons of trash or more.
When laypeople hear about the garbage patch, they often envision it as an island made of trash. To be sure, some pieces of the patch are large—barrels, balls, nets, and wrappers—but it’s not as solid as a landmass. The majority of the plastic breaks down into tiny bits, ranging from microscopic to the size of a fingernail, and these pieces of plastic become suspended in the top several hundred feet of water, forming a “plastic soup.” Because much of the debris hangs below the water’s surface, we can’t see it on satellites, but scientists and sailors traveling through the area have witnessed it. The small size of the particles is one reason it’s so hard to determine exactly how big the patch is—there’s no way to accurately measure its area.
The Trash Breakdown
We’re not the first generation to dump trash in the ocean, but until recent decades, our trash was made of natural materials and was broken down by the elements. When a wooden crate falls overboard from a ship, it biodegrades, getting slowly abraded by saltwater and devoured by bacteria. Organic materials decompose into nothing, but unfortunately, we don’t use as many of those materials as we used to. The Great Pacific Garbage Patch arose when humans began fabricating everything from plastics, which don’t undergo the same decomposition process as other materials do. Plastic doesn’t biodegrade, it photodegrades. Sunlight causes it to break down into smaller parts, but it takes a lot longer, and those small bits are still plastic polymers. What was once a bottle cap will disintegrate into thousands of tiny plastic particulates, all waiting to be eaten by a passing fish or bird.
Because the tiny particles are actually more dangerous than large objects, the trash vortex has had a measurable effect on wildlife. According to the UN Environment Program, plastic debris results in the deaths of more than a million seabirds and more than one hundred thousand marine mammals each year. They mistake the brightly colored specks for food; accumulated plastics in the stomachs of these animals cause them to think they’re full, so they subsequently starve to death.
People may not be moved by the sight of a dead albatross chick with a belly full of plastic, or a sea turtle choked by plastic netting, but the garbage patch has effects on animals that are part of the human food chain, too. Although the area of deep ocean where the patch occurs doesn’t have the nutrients to support large fish populations, pelagic fish such as tuna pass through it, and when they ingest the plastic pellets, they’re also ingesting all the chemicals the plastics have absorbed from the surrounding water. Some plastics from the garbage patch contain pesticides like DDT, PCBs, and other oils and pollutants. The plastics also affect the filter-feeding organisms that live in the top layer of the ocean; as these organisms filter water, they take in plastics and chemicals, then pass them on to the fish who feed on them.
