Plastic waste has been found in the most remote places — including, now, a deep-sea canyon off the coast of Argentina, according to a recent study.
“The very first item spotted was a plastic bag entangled on the seafloor,” said Diego Urteaga, study co-author and a marine biologist at Argentina’s Bernardino Rivadavia Museum of Natural Science, told Mongabay by email. “Seeing something so clearly associated with human activity lying on the seafloor at more than 1,000 meters [3,281 feet] depth was striking.”
Urteaga and his colleagues used a remotely operated vehicle (ROV), equipped with high-definition cameras, to survey the Mar Del Plata Submarine Canyon in the southwestern Atlantic. The V-shaped canyon is located about 250 kilometers (155 miles) off Argentina’s coast.
The study was originally designed to document the canyon’s biodiversity and habitats, but the “litter became impossible to ignore,” Urteaga said.
Over 17 dives, the team observed 29 pieces of litter — mostly plastic, some rubber, including an isolated plastic tissue-paper packaging at a depth of 3,814 m (12,513 ft).
“I was particularly surprised by the variety of objects we found,” Urteaga said. “They included fishing gear, plastic bags and wrappers, a plastic cup, and even a rubber boot.”
The litter didn’t exist in isolation. Researchers observed marine organisms attached to it, including a sea star on a plastic bag and a fishing rope colonized by organisms, Urteaga said. “These observations are interesting because they show that litter does not simply disappear after reaching the deep sea: It can remain there and become part of the physical environment experienced by benthic organisms,” he said.
Urteaga added that it’s still unclear whether the interactions between the organisms and litter are “neutral, harmful, or occasionally beneficial.”
Some estimates suggest that roughly 80% of marine litter originates on land and is carried to sea by rivers. However, the researchers suspect that most of the litter in the Mar Del Plata Submarine Canyon came from offshore activities, including fishing. This is because the canyon is far from Argentina’s coast and the litter is dominated by plastic and fishing-related materials such as ropes and lines.
“[T]he overall composition provides evidence for a substantial contribution from activities at sea,” Urteaga said. “In the case of fishing-related debris, preventing gear loss and improving the recovery and disposal of damaged or unwanted fishing gear could be particularly important.”
The study shows that human activity touches even remote and very deep ecosystems, Urteaga added.
“What was most unsettling was the contrast between the extraordinary natural environment we were exploring and the very familiar objects we suddenly encountered,” he said. “We were looking at animals and habitats that very few people have ever seen in their natural environment, and then a piece of human-made debris would appear in the middle of the scene.”
Banner image: Examples of deep-sea litter found in the Mar del Plata Submarine Canyon. (A) Medium-sized plastic wrapper. (B) Rubber boot. (C) Food wrapper. (D) Snack wrapper. (E) Tissue paper wrapper,. (F) Sediment-filled plastic bag. Image courtesy of Teso et al. (2026) (CC-BY 4.0).
