Researchers Find Microplatics At Bottom Of Mariana Trench, Plastic Cleanup Plan Hits Snag

The extent of microplastic pollution in the oceans is far greater than anticipated. Researchers from China have found the highest concentration of microplastics in the deepest part of the ocean — the Mariana Trench. How deep it is it? Let’s put it this way. Mount Everest is 8,850 meters high. The bottom of the Mariana Trench is more than 11,000 meters beneath the surface.

Researchers from the Institute of Deep Sea Science and Engineering in Hainan found the concentration of microplastics increased the deeper they went. At the bottom, they recorded a maximum of 2,200 pieces per liter in sediments and 13 pieces per liter in water. They found that most of the marine life in that part of the ocean had ingested microplastics which then became lodged inside their bodies. The research was published on November 19 in the journal Geochemical Perspectives.

“Manmade plastics have contaminated the most remote and deepest places on the planet,”  the researchers tell The Guardian. “The hadal zone is likely one of the largest sinks for microplastic debris on Earth, with unknown but potentially damaging impacts on this fragile ecosystem.”

Most of the microplastics were fibers a few millimeters long, most likely from clothing, bottles, packaging, and fishing gear. Polyester was the most common plastic in the sediments, and polyethylene terephthalate, used for bottles and clothing, was most frequent in water samples.

Cleanup Effort Stalls

Ocean Cleanup, a startup based in The Netherlands, began testing a 600-meter-long floating boom it thinks will be able to remove a significant amount of floating plastic trash from the Pacific Ocean. Founded by Boyan Slat, it has raised $20 million to construct a number of prototypes. The first of them, nicknamed Wilson after the ball in the movie Castaway, began testing 250 miles off the coast of California in September.

To date, the contraption has done a fine job of collecting plastic trash. Unfortunately, it can’t retain it after it captures it. Slat tells The Guardian the slow speed of the solar-powered boom means it is unable to retain the plastics it captures, which fall out of the bottom and back into the ocean. He says a team of experts is now working on a possible fix.

“What we’re trying to do has never been done before. So, of course we were expecting to still need to fix a few things before it becomes fully operational,” Slat explains. Engineers will work for the next few weeks to widen the span of the floating barrier so that it catches more wind and waves to help it go faster, he says.

The team released a statement earlier this week that said, “Eventually the only way to truly see how the system would perform was to put it in the environment it has been designed for, and this application has been largely effective, since most of the design has withstood the tests of the Pacific, such as its ability to accumulate plastic, reorient with the wind and survivability. For the beta phase of a technology, this is already a success.”

Critics are numerous and vocal. Chief among them is George Leonard, lead scientist of the Ocean Conservancy, a nonprofit environmental advocacy group. He says a solution must include stopping plastic from reaching the ocean in the first place and educating people to reduce consumption of single-use plastic containers and bottles.

Slat agrees but adds, “This plastic doesn’t go away by itself and to just let hundreds of thousands of tons of plastic out there to be fragmented into these small and dangerous microplastics to me seems like an unacceptable scenario.” For someone only 24 years old who has been working on the Ocean Cleanup project for 5 years already, he makes a lot of sense.