科学美国人60秒:Quarter-Million Tons of Plastic Plague Oceans

The Great Pacific Garbage Patch may be the most infamous of the world's floating trash dumps. But it's far from the only one. There's plastic trash littering "the Bay of Bengal, the Mediterranean Sea, the coast of Indonesia, all five subtropical gyres; coastal regions, enclosed bays, seas and gulfs." Marcus Eriksen, director of research at the Five Gyres Institute. 

Eriksen surveyed those areas, along with his seafaring colleagues. Collectively, they spent some 900 hours logging every large piece of plastic they could spot from their boats. And they trawled for plastic nearly 700 times along the way, picking through their nets and cataloguing the debris. "I find the necks of bottles, fragments of toothbrushes and combs. Action figure parts. Army men. I find a lot of army men." 

The researchers plugged that trash census data into ocean models, which simulate the circulation of the world's waters. Based on the densities of trash the researchers found, the models predicted some 5.25 trillion particles of plastic may be floating out there…adding up to about 269,000 tons. And more than 90 percent of those pieces may be smaller than a grain of rice. The study appears in the journal PLOS ONE. [Marcus Eriksen et al: Plastic Pollution in the World’s Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea]

What happens to all that plastic? "The ocean's going to take it, blast it to smithereens, it's going to cycle it through marine organisms, and sink it to the sea floor. That's the ultimate life cycle, I believe, for plastics. We're like constantly sprinkling fish food on the entire ocean surface." The solution, Marcus says, isn't some fleet of seafaring garbage trucks. It's keeping our trash to ourselves—which would be a sea change in behavior.

—Christopher Intagliata