Filipino researchers visited the Emden Deep, also known as the Galathea Deep or Galathea Depth, the third deepest trench on the ocean’s planet, more than 10,000m below the surface and found plastic debris.

“It has been estimated that 4.8 to 12.7 million metric tons of plastic waste entered the ocean in 2010 from 192 coastal countries.”

A plastic bag found by Victor Vescovo, when he descended nearly 10,927m (nearly 6.8 miles) to a point in the Pacific Ocean's Mariana Trench, one of the deepest part of the ocean.  He also found a sweet wrappers. 

HUGE DUMP FOUND AT THE BOTTOM OF THE MEDITERRANEAN

Images obtained by an underwater exploration robot at the seafloor of the Strait of Messina in Italy, have revealed the largest concentration of garbage ever recorded in deep waters anywhere in the world.  

The photos extracted from ROV video footage show examples of benthic litter accumulations observed within channels in the Messina Strait, including: bricks, tires, clothes and large metallic objects, small  and large mounds, sometimes formed around large items such as a buried car and a sunken boat.

Litter is patchy but pervasive on all surveyed channels, reaching densities up to 200 items in 10 meters of observation. Such impressive amount of litter can be explained by submarine canyons acting as carrier of marine litter from shallow water to the deep sea and a strong urbanization of the coastal area. 

Fishes swiming near plastic debris at the Samandag Cevlik Akcay dive site off the coast of Samandag, in Hatay province, Turkey.

Using an Ocean Infinity AUV (Autonomous Underwater Vehicles), Argentina found the submarine ARA San Juan, the Argentine Navy submarine which was lost on 15 November 2017.  The ARA San Juan had been found at 907 m depth, 500 km off Comodoro Rivadavia, in Southern Argentina.

Source:  Argentine navy @Armada_Arg

A plastic ice bag, likely blown overboard from a fishing vessel found at a depth of ~3,700 m in Enigma Seamount, near the Mariana Trench

Examples of litter observed on the seafloor in the Nordic Seas

A. rubber glove, B. gill net, C. trawl wire, D. Drinking cartons, E: soft plastic, F: Plastic straps, G: Plastic bag.

Marine litter has been found in all marine environments in the Nordic Seas. These ecosystems are under pressure from climatic change and fisheries while the human population is small. According to submarine video transects most of the litter is originated from the fishing industry and plastic is the second most common litter. Background levels are comparable to European records and areas with most littering had higher densities than in Europe.

Photo curtesy of Mareano-IMR