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The largest habitat for life on Earth is the deep ocean. It's home to everything from jellyfish to giant bluefin tuna. Now the deep ocean is being invaded by tiny pieces of plastic - plastic that people thought was mostly floating at the surface. NPR's Christopher Joyce reports on an ocean expedition that has turned up troubling results.
CHRISTOPHER JOYCE, BYLINE: There is a place along the California coast where the edge of the continent takes a steep dive into the deep ocean - Monterey Bay. Whales and white sharks swim these depths just a few miles offshore. Scientists come here to study these depths. It's a busy place. Big research boats line the docks. I board one of them to get a look at a multimillion-dollar machine called Ventana sitting on the deck.
KYLE VAN HOUTAN: It's a massive underwater robot - robotic arms, a lot of sensors, machinery, lights, video cameras.
JOYCE: Kyle Van Houtan is chief scientist with the Monterey Bay Aquarium. With their partner, the Aquarium Research Institute, they've been sending Ventana thousands of feet deep into the bay in search of plastic.
VAN HOUTAN: The deep ocean is the largest ecosystem on the planet, and we don't know anything about the plastic in the deep ocean.
JOYCE: Scientists do know about the plastic floating on the surface. But beneath the surface - Ventana made several dives to collect water samples. Technicians filtered the water, looking for microplastic - tiny fragments and fibers you can barely see.
VAN HOUTAN: What we found was actually pretty surprising. We found most of the plastic is below the surface.
JOYCE: And also to their surprise, they found that submerged microplastics are widely distributed from the surface to thousands of feet deep. And the farther out from shore they sampled, the more microplastic they found. That suggests it's not just washing off the California coast. It's coming from all over.
VAN HOUTAN: We think that California current is actually carrying some of the microplastic debris from the north Pacific Ocean.
JOYCE: Kind of like trash washing down off a landfill that's actually in the ocean. And that trash gets eaten. Marine biologist Anela Choy is with the Scripps Institution of Oceanography in San Diego. Choy says the deep ocean is like a giant feeding trough.
ANELA CHOY: It's filled with animals, and they're not only moving up and down in the water column every day, forming the biggest migration on the planet, but they're also feasting upon one another.
JOYCE: For example, sea creatures that filter food out of the water, like larvaceans. They're the size of tadpoles, but they're called giant larvaceans because they build a yard-wide bubble of mucus around themselves. Scientists call them snot houses. The mucus captures floating plankton. That's the animal's food. And...
CHOY: We found small plastic pieces in every single larvacean that we examined from different depths across the water column.
JOYCE: Another filter feeder, the red crab, also contained plastic pieces - every one they caught. Choy has also looked beyond Monterey Bay and higher up the food chain. In the Pacific, she collected creatures called lancetfish - several feet long, huge mouths and lots of saber-sharp teeth. They're called the dragons of the deep.
CHOY: We've looked now at over 2,000 lancetfish, and we found that about 1 in every 3 lancetfish has some kind of plastic in its stomach. It's really shocking because this fish actually doesn't come to the surface as far as we know.
JOYCE: Showing that plastic has spread through the water column. Bruce Robison is an aquarium Research Institute senior scientist.
BRUCE ROBISON: The fact that plastics are so pervasive, that they're so widespread is a staggering discovery, and we'd be foolish to ignore that. Anything that humans introduce to that habitat is passing through these animals and being incorporated into the food web.
JOYCE: The results appear in the journal Nature Scientific Reports. Robeson says they reflect what's going on in Monterey Bay. But he adds 70 years of manufacturing plastic may have created a global ocean problem. Christopher Joyce, NPR News.
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