Scientists confirm the existence of another ocean garbage patch

The South Pacific patch may be as big as a million square miles, 1.5 times the size of Texas.

A team of scientists has confirmed the existence of another ocean garbage patch, this time in a remote area of the South Pacific. Unlike the famous patch in the northern Pacific Ocean, which has long been one of the world’s most recognizable symbols of pollution, the new patch is in an area that had previously been largely unstudied.

To learn more about the expedition, visit Captain Moore's project on ResearchGate.

The high degree of plastic pollution was uncovered by captain Charles Moore and his team of volunteer researchers on a six-month voyage: “We discovered tremendous quantities of plastic. My initial impression is that our samples compared to what we were seeing in the North Pacific in 2007, so it’s about ten years behind,” said Moore, who has worked to raise awareness about plastic pollution since he stumbled across the North Pacific patch while captaining a racing yacht in the 1990s. Moore says the southern patch could be as big as a million square kilometers, 1.5 times the size of Texas.

Charles Moore aboard a research vessel. Courtesy of Charles Moore.

New patch is formed by an unexplored gyre

Each of the oceans’ five major gyres has the potential to trap plastics and form a garbage patch. But while the famous patch in the North Pacific—and to a lesser extent its counterpart in the North Atlantic—has been well documented, little is known about plastic accumulation in the other gyres.

That makes the news about the South Pacific patch extremely valuable to other scientists, like Utrecht University oceanographer Erik van Sebille. He’s just begun an extensive project to track plastic distribution throughout the ocean. “There’s very little information on plastic in the South Pacific. Hardly anybody goes there, and it’s really very poorly studied,” he said. “We need observations like these to constrain our modeling, so I was excited to see Charles’ project.”

Moore’s is only the second team to collect samples of plastic pollution in the South Pacific Gyre. The first was led by marine pollution researcher Marcus Eriksen, who crossed the gyre in a single transect in 2011 and later published his findings. “At that time I saw very little debris,” Eriksen told us. Since then, an additional tens of millions of tons of plastic are thought to have made their way into the world’s oceans. Moore also attributes finding more debris on his recent voyage to the patchy nature of plastic in the ocean. One trawl may pick up next to nothing, because it missed the most concentrated spots, while the next is full of plastic, having hit one. That’s why a long research expedition over multiple months, crisscrossing a remote area off the coasts of Chile and Peru, was necessary to document the full extent of the pollution.

Millions of plastic particles per square kilometer

While the term “garbage patch” conjures up images of floating bottles and grocery bags, the South Pacific patch is comprised primarily of tiny plastic pieces, smaller than grains of rice. This may indicate that plastic in the South Pacific has a longer journey than the trash in the more infamous patch, which will eventually also break apart. “We found a few larger items, occasionally a buoy and some fishing gear, but most of it was broken into bits,” said Moore. Plastic from fishing gear is so common here because the fishing industry is particularly active in the Southern Hemisphere. “We haven’t yet done lab analysis, but based on my visual impression, an enormous area of the South Pacific has millions of plastic particles per square kilometer,” said Moore.

Once the tiny plastic particles are in the gyre, they’re next to impossible to clean up—the best hope is preventing them at the source, and the sooner the better. “Gone are the silly notions that you can put nets in the ocean and solve the problem,” said Erikson. “This cloud of microplastics extends both vertically and horizontally. It’s more like smog than a patch. We’re making tremendous progress to clean up smog over our cities by stopping the source. We have to do the same for our seas.”

A sense of urgency to let the world know

Having returned from their expedition in early May, Moore and his team are processing and cleaning their samples, so they can study the plastic more closely. It will be a while before they have results ready to publish—the plastic particles collected at sea have to be carefully weighed and analyzed—but Moore wants to share his initial observations now. “Having spent so much time there, I feel like an ambassador,” he said. “There’s a sense of urgency to get information out about this area, because it’s being destroyed at an enormously accelerated rate. For much of the unexplored ocean, we will never have pre-plastic baseline data.”