This story originally aired on NPR on July 24, 2018
When a huge floating gyre of plastic waste was discovered in the Pacific in the late 1980s, people were shocked. When whales died and washed ashore with stomachs full of plastic, people were horrified. When photographs of beaches under knee-deep carpets of plastic trash were published, people were disgusted.
Though some of it came from ships, most, presumably, was from land. But how much was coming from where?