Scientists Reveal Depth of Marine Litter Problem

A new seafloor survey revealed just how much the ocean is speckled with litter. Even in the deepest ocean depths you can find bottles, plastic bags, fishing nets and other types of human litter, researchers describe in the journal PLOS ONE.

Litter was found everywhere, spanning throughout the Mediterranean and all the way from the continental shelf of Europe to the Mid-Atlantic Ridge, which extends 2,000 kilometers from land.

And it is not just an out of sight, out of mind situation - it has consequences. Some animals can mistake our trash for food and eat it or it can entangle coral and fish -- a process known as "ghost fishing."

Scientists in this international study took nearly 600 samples from across the Atlantic and Arctic Oceans and in the Mediterranean Sea, from depths ranging from 35 meters to 4.5 kilometers.

Litter was located at every site visited. Plastic accounted for 41 percent of the refuse and derelict fishing gear 34 percent. Glass and metal, wood, paper/cardboard, clothing, pottery, and unidentified materials were also present.

"This survey has shown that human litter is present in all marine habitats, from beaches to the most remote and deepest parts of the oceans," Kerry Howell, associate professor at Plymouth University's Marine Institute, said in a press release. "Most of the deep sea remains unexplored by humans and these are our first visits to many of these sites, but we were shocked to find that our rubbish has got there before us."

Researchers also realized from their analysis that ships responsible for a lot of ocean litter. Eva Ramirez-Llodra, a marine biologist with the HERMIONE project, said that deposits of clinker, or residue from burnt coal dumped by steam ships - is scattered on the ocean floor.

This research also showed scientists that ocean trash can move in a particular pattern. For instance, plastics originating from coastal and land sources and are being carried along continental shelves and slopes into deep water. It is a path that cannot be ignored any longer.

"The large quantity of litter reaching the deep ocean floor is a major issue worldwide. Our results highlight the extent of the problem and the need for action to prevent increasing accumulation of litter in marine environments," Howell said.