Even the Deepest Parts of the Ocean Are Full of Trash

It isn't better down where it's wetter, take it from me.

Apr 30 2014, 9:37pm
These are some of the pieces of trash the group found. Image: PLOS One

We know from the search for Malaysia Airlines flight MH370, and the fact that there are huge garbage patches floating in the Atlantic, Pacific, and Indian Oceans there is trash floating everywhere on the oceans' surfaces. But, it turns out, there’s also heaps of trash all over the ocean floor, no matter where you look.

That’s the result of 12 years of research by European scientists who have been trying to map the ocean floor. As a side-project to that endeavor, they also cataloged all the litter and trash they found—turns out, there’s a lot of it, sometimes in places that are as far as 1,200 miles from the nearest human settlement. 

“Basically, we found litter almost everywhere we looked, from the shallow places we looked at, right on down to 4.5 kilometers beneath the surface,” Kerry Howell, a researcher at the United Kingdom’s Plymouth University and author of a new paper published in PLOS One, told me. “We found it close to land and we found it as far out as the Mid-Atlantic Ridge (about halfway between North America and Europe). We found it in places humans have never been or looked at before. Every time we put a camera down, we found it.”

As you might expect, litter was most common closer to land and at shallower depths, where Howell’s team found an average of 20 pieces of litter per hectare. At deeper parts of the ocean, the team found about two pieces of litter per hectare. 

Litter was found at literally every site surveyed, even in parts of the ocean more than a thousand miles from land. Image: PLOS One

“The most littered places were submarine canyons, which basically funnel litter from rivers into the deep sea,” she said. “And these aren’t the micro plastics you find in the garbage patches, these are big pieces.”

Howell says the team found a lot of plastic bags, discarded fishing gear, some beer cans, glass bottles, clothes, and remnants from old steam-powered boats.

The various garbage patches that take up huge parts of our seas have already been extensively cataloged, but Howell says that there hasn’t been much research into litter that actually sinks deep into the ocean. Meanwhile, the conventional thinking is that all the plastics we throw into the ocean eventually make it to shore or into one of the garbage patches, but that isn’t the case. 

“Contrary to a common notion that most plastic items float at the sea surface, it has been estimated that 70 percent of the plastic sinks to the sea floor,” the study noted. “The large quantities of litter reaching the deep ocean floor is a major issue worldwide, yet little is known about its sources, patterns of distribution, abundance and, particularly, impacts on the habitats and associated fauna.”

It’s unclear how much a tin can here or a fishing wire there actually affects underwater ecosystems, but it’s obvious that we’d rather there not be trash strewn everywhere you could possibly look.