Pham’s team collected data from surveys at 32 underwater sites in the northeast Atlantic and Acrtic oceans and the Mediterranean Sea that took place between 1999 and 2011. The highest litter density occurs in submarine canyons, whilst the lowest density can be found on continental shelves and on ocean ridges. Abandoned, derelict fishing lines and nets were most often found in areas such as seamounts and banks that host dense communities of fish and shellfish. Besides the unquestionable aesthetic issue, litter can be mistaken for food items and be ingested by a wide variety of marine organisms [3]–[8]. Fish get caught up in drifting nets, in what’s known as “ghost fishing.” And chemicals such as dioxins get consumed by small organisms and concentrated in organisms further up the food web, where these poisons can reach lethal levels. Litter was found at all the locations surveyed, from sites close to population centres such as the Gulf of Lion or the Lisbon Canyon to as far as the South Charlie-Gibbs Fracture Zone on the Mid-Atlantic Ridge, located at about 2000 km from land. “Such records were not surprising,” Pham’s team noted in their paper, “as litter is known to be present in all seas and oceans of the planet, as remote as the Southern Ocean and at depths as deep as 7,216 m in the Ryuku trench, south of Japan.” 
 
 The most common items were the ubiquitous plastic bags now banned in some cities. Contrary to a common notion that most plastic items float at the sea surface it has been estimated that 70% of the plastic sinks to the seafloor [23]. Similar studies have documented trash lining the seafloor in other areas, such as Monterey Canyon off California and the more than 7000-meter-deep Ryukyu trench off the coast of Japan [PDF]. Underwater surveys conducted at dozens of sites in the northeast Atlantic and Acrtic oceans and the Mediterranean Sea found fishing gear, plastic, metal, glass and other bits of garbage in shallow and deep waters both near and close to shore. Clinker is the residue of burnt coal, and it was common in the late 18th to 20th centuries for steam ships to dump this waste material overboard, so most of this type of trash is more than 100 years old. “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,” Pham and colleagues write. The surveyed sites were located near as well as thousands of kilometers from shore, at depths of 35 to 4,500 meters, and were located on continental shelves and slopes, ocean ridges, banks, mounds and seamounts and within submarine canyons and deep basins.
– In the depths of European oceans, you'll find coral, sand—and old Heineken cans. Yup, human litter can be found even in the most far-reaching places on the planet, according to one of the biggest scientific surveys ever done of the seafloor. Using video and trawling surveys between 1999 and 2011, scientists analyzed 32 sites in the Atlantic Ocean, Arctic Ocean, and Mediterranean Sea. They found everything from bottles to plastic bags, clothing, and fishing nets—even more than 1,200 miles from land and nearly three miles below the water's surface, the Guardian reports. Not a single site was litter-free. That means your garbage is on continental shelves, ocean ridges, and deep canyons—the worst spot for garbage build-up, the study says. Plastic was most common at 41% of the garbage found, while 34% was related to fishing—think nets and lines. Also spotted: wood, pottery, glass, paper, cardboard, and even burnt coal residue left from steam ships more than 100 years ago. "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," a researcher says. "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." Smithsonian notes some 14 billion pounds of garbage enter the oceans each year, some of which animals eat, get tangled in, and often die.