Experts estimate that 5.25 trillion plastic particles—weighing in at nearly 269,000 tons—are floating in the world’s oceans. A new paper in the open access journal PLOS ONE (doi:10.1371/journal.pone.0111913) about the abundance of plastic in the oceans combines data from 24 expeditions between 2007 and 2013. These expeditions cover all five subtropical gyres—areas of high pressure where seawater churns and sinks—as well as Australian coastal waters, the Bay of Bengal, and even the Mediterranean Sea.
Using data about the abundance of microplastics dredged up in nets and visual sightings of large plastics, the researchers created a numerical model that estimated the total extent of plastics in the ocean. They found that larger plastics populate coastal waters, whereas microplastics are more common in remote regions, even reaching as far as subpolar gyres. This distribution pattern may be a clue about a larger degradation pattern that plastics face when they enter the world’s oceans.
“Our findings show that the garbage patches in the middle of the five subtropical gyres are not the final resting places for the world’s floating plastic trash. The endgame for microplastic is interactions with entire ocean ecosystems,” said Marcus Eriksen, research director of the 5 Gyres Institute.
—JoAnna Wendel, Staff Writer
Citation: Wendel, JoAnna (2014), New data aid estimate of ocean’s plastic content, Eos Trans. AGU, 95(50), 477, doi:10.1002/2014EO500005.