Around 60 billion tons of plastic are produced each year, about 10 percent of which ends up in the sea. About 20 percent of this is from ships and platforms, the rest from land. In other words, about 80 percent of the trash that ends up in the ocean comes from onshore. The wind carries it, sewage pipes spill it, even our garbage disposals make ways for waste to enter storm water drains and to eventually flow out into the ocean.

Take a walk along the beach anywhere in the world and you’ll find plastic bags, bottles, and containers. Along with traffic cones, disposable lighters, old tires, and toothbrushes, these items have been casually tossed away. From the shore, they get carried by wind and tide to the sea. Currents bring them here, to the largest dumpsite in the world, where they join the mass of plastic, paper, oil, rubber, wood, rope, fishnets, and virtually every other type of material on the planet.

We’ve already seen how pollutants from local landfills contaminate air, soil, and groundwater. But the oceans are vast. And when toxins pollute the sea, there is potential for even greater environmental hazard. Oceans occupy 70 percent of the Earth’s surface and are home to over 90 percent of all life on the planet. Seafood is the primary source of protein for many coastal peoples. Worldwide, nearly a billion people rely on fish for a big source of their daily food protein. When we pollute the water, we pollute the fish.

The Eastern Garbage Patch through which I am sailing off the coast of Hawaii is contributing to the ocean’s demise. Rivers, streams, and sewage pipes propel waste out to sea, and it eventually ends up here. This is the place about which we sometimes wonder: "Where does all the sewage go that’s pumped out into the ocean?" In this area there are about a million pieces of garbage within every square mile, according to some estimates. Currents pull and drag garbage in this direction, not far from where pirates, I’m told, used to search for bodies fallen overboard. They understood the movement of the currents, and knew where to find drifting loot and corpses. This is also near where the first Hawaiians are said to have landed from Polynesia.

Hawaii acts as a comb for the Garbage Patch. Nineteen islands and atolls comprise the Hawaiian Islands. They sit smack between North America and Asia in the middle of the Pacific Ocean and are the most remote islands on Earth. The Eastern Garbage Patch is estimated to fl oat between the coast of California and the Hawaiian Islands; and there’s a "superhighway" from there to another ocean garbage patch just south of Japan, the Western Garbage Patch. That patch collects trash from Asia, Russia, India, and the Malaysian Peninsula and deposits tons of trash on the south coast of Japan; its concentration of debris is said to be even higher than what I am seeing here.

The superhighway acts like a funnel connecting the two garbage patches. It’s how whiskey bottles from Japan, pill bottles from India, Korean detergent containers, and oil cartons from Guatemala make their way to the Hawaiian shores. Those are things I saw firsthand.

Captain Charles Moore has been investigating the Eastern Garbage Patch since 1997, when he stumbled across it while speeding across the ocean during the Transpacific Yacht Race. The TransPac race starts in Los Angeles and ends in Honolulu.

"Usually, you go in a straight line and you don’t go through the Garbage Patch. But there was an El Niño in ’97, and a