Keeping you current

The Great Pacific Garbage Patch Is Much Larger and Chunkier Than We Thought

A new study shows the patch is not just microplastics. Fishing gear and large pieces make up 92 percent of the trash

Debris recovered from the Garbage Patch (The Ocean Cleanup)
smithsonian.com

The Great Pacific Garbage Patch has received a lot of attention over the last couple decades. But for all the media coverage, researchers still didn't know a lot about it, until now. As Laura Parker reports for National Geographic, a new study takes a closer look at the trash and the results suggest it's a bit different than we imagined.

The patch contains around 79,000 metric tons of trash, making it four to 16 times larger than previously estimated. What’s more, it's made up of a surprisingly large percentage of sizable debris—and it's collecting incredibly fast.

First discovered in 1997, the Great Pacific Garbage Patch was never a physical mass of objects, but rather a soup of tiny plastic debris. Oceanographer and sailboat racer Charles Moore noticed the plastic soup while sailing his yacht in the Pacific ocean between Hawaii and California. The patch (in fact, there are two patches, a western and eastern patch) is created by the North Pacific Subtropical Gyre, a system of circular currents that tend to draw debris into its stable center, trapping it.

While the patch doesn't contain any "land" per se, it solidified in the popular imagination, often touted as a "floating mass" the size of Texas. Just last year, as a PR stunt, the conservation group Plastic Oceans Foundation and some advertising gurus petitioned the U.N. to recognize the Patch as a new nation, called Trash Isles. They even mocked up a passport, stamps, and a currency called “debris.”

But the idea of a "continent" of trash is far fetched. In a 2016 article debunking the myth, Daniel Engber at Slate described the patch as a soup of trillions of pieces of microplastics, which are created as plastic degrades. (Microplastics are also commonly included in many cosmetics.) Such itty bitty plastics can make their way into the food chain—and researchers are still sorting out the impacts.

The latest research on the Garbage Patch, however, suggests it's made up of more than just tiny bits.

To get a handle on what's in the patch and just how large it is, a team of oceanographers commissioned by the conservation group Ocean Cleanup undertook a comprehensive study of the patch. According to a press release, previous studies were not able to accurately assess the volume of trash in the patch because they used small nets to sample the debris, which excluded larger chunks.

To remedy this issue, the Ocean Cleanup team used 30 boats that simultaneously surveyed the patch over the course of a summer, supplemented by two aircraft. One of the ships trawled with two 19-foot-wide devices, sampling for very large objects. The aircraft were outfitted with multispectral and 3D sensors to scan the ocean surface for large pieces of garbage as well. The study appears in the journal Scientific Reports.

The team found that the patch spans an area three times the size of France, containing 1.8 trillion pieces of mostly plastic debris. Overall, this is the equivalent to the weight of 500 jumbo jets. Surprisingly, they found that large pieces of plastic made up 92 percent of that mass, while microplastics accounted for only 8 percent. It turns out, the patch is more like a chunky stew than a soup.

“We were surprised by the amount of large plastic objects we encountered,” Julia Reisser, chief scientist of the expedition says in the release. “We used to think most of the debris consists of small fragments, but this new analysis shines a new light on the scope of the debris.”

In fact, 46 percent of the debris in the patch is lost or discarded fishing gear, including “ghost nets” which drift through the ocean tangling up animals as they go. “I knew there would be a lot of fishing gear, but 46 percent was unexpectedly high,” oceanographer Laurent Lebreton, lead author of the study tells Parker. “Initially, we thought fishing gear would be more in the 20 percent range. That is the accepted number [for marine debris] globally—20 percent from fishing sources and 80 percent from land.”

It’s also believed up to 20 percent of the debris in the patch could have been washed into the ocean during the devastating 2011 tsunami in Japan.

Perhaps counterintuitively, the fact that the patch is chunkier than expected is good news. Cleaning up microplastics is very difficult, if not impossible, while recovering fishing gear might actually be a feasible task, but far from easy. As Livia Albeck-Ripka at The New York Times reports, conventional methods like trawling nets would not work for cleaning up the patch. That's why the Ocean Cleanup Foundation, founded by Dutch teenager Boyan Slat (now 23) has been attempting to develop a system that will concentrate microplastics and debris for easier cleanup.

The Foundation's ambitious designs have garnered much criticism, and experts worry their methods could hurt wildlife. But oceanographers say something needs to be done, whether it's in the ocean or on land, where much of the pollution originates.

“Plastic pollution in the ocean is visible and trackable,” marine researcher Britta Denise Hardesty of the Australian research group CSIRO tells Marian Liu at CNN. “We can definitely make a difference in how we vote with our pocketbook and think about each decision we make, whether we take our own bags to the supermarkets, refuse straws, bring our own coffee cups, accept single-use items or think about mindful alternatives.”

Another solution is finding inexpensive and feasible ways for fishermen to dispose for old fishing nets to prevent abandoning of equipment, an idea central to the NGO-led Global Ghost Gear Initiative.

About Jason Daley

Jason Daley is a Madison, Wisconsin-based writer specializing in natural history, science, travel, and the environment. His work has appeared in Discover, Popular Science, Outside, Men’s Journal, and other magazines.

Read more from this author |
Tags

Comment on this Story

comments powered by Disqus