Photo: ALAN JAMIESON / NEWCASTLE UNIVERSITY

The bottom of the Mariana Trench, in the western Pacific Ocean, is the deepest point in any ocean of the world.  At its deepest, the bottom is over 36,000 feet below the surface. In comparison, Mount Everest is 29,000 above sea level, or over a mile shorter than the trench is deep.  

Researchers studying animals that live in these great depths have made several disturbing discoveries. Alan Jamieson, a marine biologist at Newcastle University, has been studying amphipods—scavenger relatives of crabs and shrimp that dwell in the deepest abyss. A few years ago, he tested these tiny creatures for pollutants and found high concentrations of toxic polychlorinated biphenyls, or PCBs. PCBs have been banned for decades but persist in nature. Recently, Jamieson and his team started testing the amphipods for plastics.

As reported by the Atlantic: They“eventually found plastic fibers and fragments in 72 percent of the amphipods that the team collected, from all six trenches that they had surveyed. In the least polluted of these sites, half of the amphipods had swallowed at least one piece of plastic. In the 6.8-mile-deep Mariana Trench, the lowest point in any ocean, all of the specimens had plastic in their gut. …

If trenches from places as distant as Japan, Peru, and New Zealand can be contaminated, it’s likely that humanity’s plastic fingers have stretched into every part of the ocean, including habitats we have barely begun to understand. No marine ecosystem is untouched. “It builds upon a growing body of evidence suggesting that the deep sea, by far the largest habitat on the planet, may very well be the largest reservoir of plastic waste on the planet,” says Anela Choy from the University of California at San Diego.

“It’s not a good result,” Jamieson adds. “I don’t like doing this type of work.””