Imagine if plastic had been invented when the pilgrims sailed from Plymouth, England, to North America. What if the Mayflower had been stocked with bottled water and plastic‑wrapped snacks? The plastic trash from their voyage would probably still be around, four centuries later.

If the pilgrims had been like many people today, they might have tossed their trash over the side of their ship. Atlantic Ocean waves and sunlight would have worn all that plastic into tiny bits. Those bits might still be floating around, waiting to be eaten by fish or oysters, and ultimately perhaps by one of us.

Plastic wasn’t invented until the late 19th century. Mass production of it took off around 1950. In only 70 years, we have produced a whopping 9.2 billion tons of plastic. Of that, more than 6.9 billion tons have become waste. And of that waste, a staggering 6.3 billion tons were never recycled.

No one knows how much unrecycled plastic ends up in the ocean. In 2015, Jenna Jambeck, a University of Georgia engineering professor, made an estimate.

Jambeck projected that between 5.3 and 14 million tons end up in the ocean each year. Most of it isn’t thrown off ships, though. It’s dumped on land or in rivers, mostly in Asia. It’s then blown or washed into the sea. It’s unclear how long it will take for that plastic to completely biodegrade, or break down. Estimates range from 450 years to maybe never.

How did we get here? Plastic has transformed our lives as few other inventions have. Plastic eased travel into space. It revolutionized medicine. It even extended the life of food, in the form of plastic wraps.

Plastic was even used to save wildlife. In the mid‑1800s, piano keys, combs, and other trinkets were made of elephant ivory. With the elephant population at risk and ivory scarce, a company in New York City offered a reward to anyone who could come up with an alternative.

An inventor named John Wesley Hyatt took up the challenge. He created a new material, celluloid. It was made of cellulose, the polymer found in all plants. It became known as plastic. Anything and everything could be made of plastic, and so it was, because plastic was cheap to make.

Henderson Island is a tiny, uninhabited island. It sits in the middle of the Pacific Ocean. The nearest major population center is some 4,800 kilometers (3,000 miles) away. Though it is half the size of Manhattan, more than 19 tons of trash litter its white, sandy beaches, much of it plastic.

Researchers estimate that it has the highest concentration of debris of any place in the world. They believe it has more than 37 million pieces of trash. For every square meter you walk, on average you’ll find 672 pieces of trash. For each visible piece of debris on the beach, two pieces are buried in the sand.

How does so much trash wash ashore on Henderson Island? Trash bobs across global seas until it gets swept into the South Pacific gyre. The gyre is a circular ocean current that functions like a conveyor belt. It collects trash and sends it straight to Henderson’s shore at a rate of more than 3,500 pieces a day.

Henderson Island

an uninhabited island prized for its animal diversity

• More than 37 million pieces of plastic on the island
• More than 3,500 pieces washing up daily