Deep plastic

The depth of the Mariana Trench makes it impossibly hostile to surface-dwelling life. Water pressure is more than 1000 times that at sea level, and temperatures rarely rise above 4 degrees Celsius. Humans have been there only four times, yet in May of this year researchers from Japan’s Global Oceanographic Data Center found a plastic bag at its bottom.

This bag has the dubious distinction of being the deepest known piece of plastic waste. Yet it is only one of the thousands of pieces of rubbish catalogued in the centre’s Deep Sea Debris Database, which also includes fishing nets, tyres, washing machines, bottles, tins, sneakers … even a gym bag. Of these items, more than 33 per cent are plastic, and 89 per cent of those are single-use products such as plastic bottles and utensils, ratios that increase to 52 per cent and 92 per cent at depths of more than 6 kilometres.