We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Occurrence and potential hydrodynamic controls of microplastics in surface sediment of the Manila Trench, northeastern South China Sea
AI summary Read the abstract
Scientists found microplastics buried deep in the Manila Trench, one of the ocean's deepest points, showing that plastic pollution isn't just floating on the surface or washing up on beaches, it's reaching even the most remote parts of our planet. Underwater "avalanches" called turbidity currents appear to sweep plastic debris down through canyons into the trench, where heavier plastic types settle and accumulate. This matters because it reveals the deep ocean is becoming a long-term dumping ground for plastic waste, which can enter marine food chains and eventually make its way back to our dinner plates.
Microplastics (MPs) have been increasingly reported in deep-sea sediments, yet their occurrence and hydrodynamic controls in trench environments, particularly those influenced by contemporary turbidity currents, remain poorly understood. Here, MPs were extracted from surface sediments collected from the Manila Trench and analyzed together with regional sedimentary dynamics. MP abundances ranged from 133 to 193 items kg, with fibers and fragments dominating the assemblages. High-density polymers (polyethylene terephthalate and polyvinyl chloride) were more abundant than low-density polymers (polyethylene and polypropylene), and mean MP particle size increased significantly with water depth, suggesting a potential influence of hydrodynamic sorting. Episodic turbidity currents may facilitate the transport of MPs with different densities into the deep sea. During subsequent settling, low-density MPs may remain suspended for longer and undergo further transport by deep currents, whereas high-density MPs may settle more rapidly and be preferentially retained in the sediments. These pattern suggests that canyon-trench systems may act as potential transport pathways and depositional sinks for MPs in the deep ocean.
More Papers Like This
Stratification and deposition pathways of microplastics in the abyssal sediments of the Philippine Sea
AI summary Read the abstract
Scientists analyzed sediment cores drilled from the deep Philippine Sea to understand how microplastics sink and accumulate in the ocean's most remote depths. They found microplastics at every layer studied, with concentrations peaking near both the surface and the deepest layers, and discovered that the sediment's chemistry and mineral composition help govern how particles migrate downward. This research reveals that even the abyssal ocean — far from human activity — is accumulating plastic debris, with geological and chemical forces influencing where it ends up.
Microplastic contamination in deep -sea sediments: the case of the Kuril Kamchatka trench.
AI summary Read the abstract
Researchers characterized microplastic contamination in sediments collected from the Kuril-Kamchatka deep-sea trench in the Pacific, finding plastic particles in these some of the deepest and most remote ocean environments on Earth. Deep-sea trenches appear to act as final sinks for microplastics transported by ocean currents and biological processes.
Direct Evidence That Microplastics Are Transported to the Deep Sea by Turbidity Currents
AI summary Read the abstract
Researchers provided the first direct field evidence that underwater sediment avalanches, called turbidity currents, transport microplastics from shallow waters into the deep sea through submarine canyons. By monitoring water flow and sampling the seafloor, they confirmed that these natural events carry significant quantities of microfibers and plastic fragments to deep ocean environments. The discovery helps explain how microplastic pollution reaches even the most remote parts of the ocean floor.
The ocean’s ultimate trashcan: Hadal trenches as major depositories for plastic pollution
AI summary Read the abstract
Analysis of hadal trenches - the deepest points in the ocean - found them to be major accumulation zones for microplastics and plastic debris, with concentrations higher than many surface ocean regions. This reveals that plastic pollution has reached the most remote and extreme environments on Earth, transported by deep-sea currents to ultimate depositional sinks.
Microplastics contaminate the deepest part of the world’s ocean
AI summary Read the abstract
Microplastic concentrations were measured in bottom water and sediments of the Mariana Trench, finding hadal bottom water concentrations of 2.06–13.51 pieces/L—several times higher than open ocean subsurface water—and sediment concentrations of 200–2,200 pieces/L. The study provides the first evidence that the world's deepest ocean environment is heavily contaminated with microplastics, likely through sinking and current-driven accumulation.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.