stylistic:style_transfer, linguistic:voice_change, structural:reformatting
Pollution

In 2016, a research expedition looked at the chemical makeup of crustacean scavengers collected from the range of 7,841–10,250 m (25,725–33,629 ft; 4,288–5,605 fathoms) within the trench. Within these organisms, the researchers found extremely elevated concentrations of PCBs, a chemical toxin banned in the 1970s for its environmental harm, concentrated at all depths within the sediment of the trench. Further research has found that amphipods also ingest microplastics, with 100% of amphipods having at least one piece of synthetic material in their stomachs.

In 2019, Victor Vescovo reported finding a plastic bag and candy wrappers at the bottom of the trench. That year, Scientific American also reported that carbon-14 from nuclear bomb testing has been found in the bodies of aquatic animals found in the trench.