Microplastics are being found in another place once thought inaccessible to conventional pollution: deep-sea hydrothermal vents more than 2,000 meters (6,562 feet) below the ocean's surface.
What's happening?
As Science Alert reports, a team of researchers from the Korea Research Institute of Biotechnology and Biomedicine studied snails and mussels from hydrothermal vent communities in the North Fiji Basin in the southwest Pacific Ocean and along the Central Indian Ridge in the Indian Ocean.
Researchers have discovered tiny plastic fragments inside animals living in these remote hydrothermal vent ecosystems, adding another item to a list that already includes ancient rocks, human bones, and wildlife across the planet. The results revealed the presence of microplastics in 11 of the 12 animals tested—around 92%—as published in the journal Water Research.
Marine biologist Se-Joo Kim from the Korea Research Institute of Biotechnology and Biomedicine said: "Plastic pollution has even spread to deep-sea hydrothermal ecosystems, which were once considered among the most isolated environments on Earth.".
On average, 3.42 pieces of plastic were found in each animal, with polystyrene being more common than any other material. The researchers also found that feeding habits and habitat appear to influence where the particles accumulate.
In bottom-dwelling snails, plastic accumulated in the digestive tract. In filter-feeding mussels, the particles were more evenly distributed throughout the animals' tissues. Snails and mussels from the Indian Ocean had significantly higher microplastic levels than snails and mussels from the southwest Pacific, suggesting that nearby pollution sources, ocean circulation, and river systems may influence how plastic reaches deep-sea areas.
Why is this important?
Because hydrothermal vents are among the most extreme and remote habitats on Earth, the discovery of microplastics there suggests that few, if any, ecosystems remain beyond the reach of plastic waste from land or surface waters.
There is also a concern for human health, as scientists are still working to understand the full impact of microplastics on living tissue, as the particles have already been found in the human body and throughout the food chain.
As the researchers wrote: «In all four hydrothermal vent species studied, microplastics were detected in almost all individuals, but the amounts varied considerably between them.».
What is being done?
The study gives scientists a clearer understanding of where microplastics ultimately end up, which could help improve monitoring systems and strengthen protection for vulnerable ecosystems. Because hydrothermal vents are located at great depth and difficult to access, cleanup is not considered a practical solution.
Thus, prevention remains the primary strategy. Goals include reducing plastic waste before it reaches rivers and oceans, improving recycling systems, and replacing some traditional plastics with safer alternatives. The most significant impact will likely be achieved through large-scale policy and industrial changes.
Reducing the use of single-use plastics, choosing reusable containers, supporting local and national efforts to improve waste management, and finding products with less unnecessary plastic packaging can help reduce the amount of new plastic entering the environment.
«"Our results provide important scientific evidence for the design of future deep-sea monitoring systems and conservation policies," Kim said, noting that their research could guide future conservation efforts in places most people never see.
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