IN BRIEF
- Researchers found human-made rubbish during 10 of 17 dives into the Mar del Plata Submarine Canyon.
- Starfish and corals were found attached to some debris, but researchers warn it may not be a suitable habitat.
Scientists exploring a deep-sea canyon off the coast of Argentina have found plastic bags, food packaging, fishing gear and an old boot thousands of metres beneath the ocean's surface.
The rubbish was discovered during the first expedition to capture images of the seafloor in the Mar del Plata Submarine Canyon, in the southwestern Atlantic Ocean.
Researchers say the findings provide further evidence that human-made waste is reaching some of the world's deepest and least-explored marine environments.
The international research team, led by Dr Daniel Lauretta of Argentina's natural science museum, conducted 17 dives using a remotely operated submersible during the summer of 2025.
After analysing approximately 240 hours of footage, researchers identified human-made debris during 10 of the 17 dives.
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The study, published on Wednesday, also documented around 40 species that researchers say may be new to science.
What did researchers find on the seafloor?
Across the 17 dives, researchers identified 29 pieces of human-made debris.
Most were plastic, although rubber items were also recorded.
The objects included plastic bags, food wrappers, fishing gear and a boot.
Researchers found some of the rubbish buried in sediment, while other items were trapped among rocks or had been drifting through the water.
More litter was recorded inside the canyon than in surrounding areas.
The researchers said this suggested the canyon's geography and ocean currents may be funnelling debris into the area, where some items can then become trapped or buried.
The findings add to a growing body of research showing plastic pollution is not restricted to coastlines or the ocean's surface.
How is marine life interacting with the rubbish?
Researchers also documented marine animals interacting with some of the debris.
Mobile animals, including crustaceans, were observed making temporary contact with rubbish.
Other creatures had attached themselves to it.
Starfish and corals were found living on pieces of debris, including plastic packaging and fishing ropes, with some of the objects partially covered by marine life.
However, the researchers cautioned that this should not be taken to mean human-made debris provides a suitable habitat for deep-sea species.
The study instead provides further information about how marine life is interacting with rubbish after it reaches the seafloor.
The expedition also documented about 40 species that may be new to science, highlighting how little is still known about some deep-sea ecosystems.
How does rubbish reach the deep sea?
Researchers say the ocean floor is not as isolated from human activity as its depth might suggest.
Material from the surface naturally sinks through the water column, with organic matter providing an important source of nutrients for marine life living beyond the reach of sunlight.
But human-made material can also sink and be transported into deeper waters.
In the Mar del Plata Submarine Canyon, the researchers believe its geography and currents may help explain why more debris was found inside the canyon than in nearby areas.
The study found rubbish in different conditions and locations on the seafloor, including pieces partially buried in sediment, trapped in rocks and still moving through the water.
Researchers say understanding where debris accumulates is important as scientists continue to examine the extent of human influence on deep-sea environments.
Has rubbish been found this deep before?
The Mar del Plata findings are not the first evidence of human-made waste reaching extreme ocean depths.
Just months before the 2025 expedition, a plastic bag was found in the Mariana Trench, the deepest oceanic trench on Earth.
Plastic and other debris have increasingly been documented in deep-sea environments as advances in technology allow researchers to survey areas of the ocean that were previously difficult to access.
The Mar del Plata expedition was the first to capture images of the seafloor within the submarine canyon, allowing scientists to document both its marine life and the presence of human-made waste.
The researchers said their findings add to emerging evidence that material sinking from the surface into the deep ocean is not limited to the organic matter that marine ecosystems rely on.
They say the discovery of rubbish in a previously unexplored area shows that even remote parts of the ocean can be affected by human activity.
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