In the north Pacific Ocean, four currents come together to create a huge clockwise-churning vortex that stretches from the equator up to southern Canada. Trapped within this massive gyre is an ever-growing swell of trash known as the Great Pacific Garbage Patch.

Its not one island-like accumulation of debris. Clumps of plastic bottles, abandoned fishing gear and beer crates are scattered across the expanse of ocean from Japan to California, though largely concentrated in two broad patches in the eastern and western parts of the Pacific. Floating below the surface are many, many microscopic plastic particles. All of it pollutes our planet.

On one of our voyages, we came across this field that must have had four to five thousand big white laundry detergent bottles, said Mary Crowly, founder and executive director of the Ocean Voyages Institute , a nonprofit that has been working for over a decade to clean up the gyre.

They were spread out over several miles of ocean and Im sure they werent all dumped in the ocean together, she told HuffPost. The ocean has an amazing way of sorting things.

On another one of my voyages, she said, I found what I called the graveyard of ghost net fragments. Ghost nets are plastic fishing nets that have been lost or dumped overboard, often chopped up by boat propellers, and left to float in the oceans or get caught on reefs.