When explorer Victor Vescovo first set out to build a submarine that could reach the deepest corners of the ocean, he wasn’t necessarily thinking about discoveries at the bottom.
The key motivation, he said, was to prove that his submarine could reach places that never been visited before. Then he started diving.
His latest dive unearthed something far less heartening: a plastic bag and candy wrappers at the bottom of the Challenger Deep, the deepest known point on Earth. Vescovo’s team is now working to test the creatures found in the oceanic trench — organisms such as sea cucumbers and amphipods resembling giant shrimp — to determine whether they have ingested plastic.
Over time, Vescovo’s mission has evolved from a technical feat to a global scientific exploration.
“As we’ve gone through the expedition over the last several months, the scientific element has come to be much more interesting and important,” Vescovo told Business Insider in April. “We actually are doing the observations that we set out to build a system to accomplish.”
Since the Five Deeps Expedition began in December, Vescovo has completed four out of five missions. His first record-breaking dive took him 27,480 feet below sea level to the bottom of the Puerto Rico Trench, the deepest part of the Atlantic Ocean. From there, he went on to visit the South Sandwich Trench, an area between South America and Antarctica, and the Java Trench in the eastern Indian Ocean, where he discovered the mysterious jellyfish-like creature.
His final mission will be a dive in the Arctic Ocean that’s set for September 2019.
The discovery of plastic at the bottom of the Challenger Deep suggests there’s far more to learn about the effects of plastic waste on the marine environment. The United Nations estimates that more than 100 million tons of plastic waste can be found in the world’s oceans, with the majority of it from sources on land.
In the Pacific Ocean, a trash-filled vortex known as the Great Pacific Garbage Patch is believed to contain more than 1.8 trillion pieces of floating plastic, or the equivalent of 250 pieces of debris for every person on Earth. This threat to marine ecosystems will likely only get worse, with the amount of plastic in the ocean expected to triple in the next decade.
Though the Five Deeps Expedition is coming to an end, Vescovo’s $48 million submarine, the Triton 36000, has made it possible to learn how humans have affected even isolated locations that remained untouched for billions of years.
“These aren’t going to be one-off dives that are experimental in nature,” he told Business Insider. “We are trying to construct a system that opens the door to the ocean.”