A world-first comparative study
Plastic pollution reaches the deep-sea hydrothermal vents
Plastic pollution is no longer just a problem of coastlines and the ocean surface. A new study shows that microplastics have now reached one of the most extreme and isolated environments on Earth: deep-sea hydrothermal vents, more than 2,000 metres below the surface.
While the amount of plastic drifting on the ocean surface has been studied extensively, far less has been known about pollution at extreme depth even though the deep sea makes up nearly 90% of the world’s marine environment.
A world-first comparative study
A research team from the Korea Research Institute of Bioscience and Biotechnology (KRIBB), working with the Korea Institute of Ocean Science and Technology (KIOST), carried out the world’s first comparative study on microplastic accumulation in animals living at hydrothermal vents in two different ocean basins [2]. They collected deep-sea snails and mussels from vents deeper than 2,000 metres, in the North Fiji Basin in the southwestern Pacific Ocean and the Central Indian Ridge in the Indian Ocean.
The results were striking: microplastics were found in 92% of the animals examined, with an average of 3.42 particles per individual. Polystyrene, a plastic widely used in packaging and consumer products, was the most commonly detected polymer, showing that everyday plastics are making their way into even the most chemically extreme habitats on the planet.
A tale of two oceans
The comparison between the two ocean basins revealed a major regional difference: animals collected from the Indian Ocean vents contained up to 14.7 times more microplastics than those from the southwestern Pacific. This is likely linked to differences in nearby human activity, river input, and large-scale ocean currents.
The researchers also discovered that how an animal feeds affects where microplastics end up in its body. In grazing snails, particles accumulated mainly in the digestive organs, while in filter-feeding mussels, microplastics were spread more evenly across all tissue types.
Why this matters
“Plastic pollution has now spread even to deep-sea hydrothermal vent ecosystems that were once considered among the most isolated environments on Earth,” says marine biologist Se-Joo Kim of KRIBB, one of the study’s lead researchers.
The findings provide the first scientific evidence that plastic pollution originating at the ocean surface can travel thousands of metres downward, reaching some of the most remote ecosystems on the planet. It’s a powerful reminder that there may be no part of the ocean left untouched by plastic — no matter how deep, dark, or far from human activity.
The study was published online on 3 June 2026 in Water Research, one of the leading international journals in environmental and water science.
Sources
- Microplastics Reach Even 2000 Meters Below The Ocean Surface Study Finds First Cross-Ocean Study Reveals How Microplastics Accumulate In Deep-Sea Hydrothermal Vent Animals
- Microplastics Found 2,000 Meters Deep in Hydrothermal Vent Animals
- ‘Most Isolated Environments’: Microplastics Are Finding Their Way Down to Deep-Sea Hydrothermal Vents : ScienceAlert
- Microplastics reach even 2,000 meters below the ocean surface, study finds
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