mariana Trench plastic pollution

The bag at the bottom of the Mariana Trench
The world's deepest plastic bag has been found at the bottom of the Pacific Ocean's Mariana Trench, highlighting the spread of ocean pollution.

Scientists made the discovery at 36,000ft (10,898m) in the world's deepest ocean trench, one of 3,000 pieces of man-made debris dating back 30 years.

Numerous international teams working around the world on over 5,000 separate dives and using deep-sea remote vehicles helped study the ocean beds to discover what lies beneath.

Over a third of the debris found was micro-plastic, with 89 per cent from single-use products.

The full findings of the study have been published in the journal Marine Policy. It shows how human activities are now also affecting deep-sea ecosystems.

The report said: "There is growing concern that deep-sea ecosystems are already being damaged by direct exploitation of both biological and non-biological resources - through deep-sea trawling, mining and infrastructure development, for example."

Scientists from the Japan Agency for Marine-Earth Science and Technology in Yokosuka made the discovery. Other waste found by the probe include metal, rubber, fishing gear, glass and various other man-made items.

The issue of plastic pollution and human impact on the oceans has captured the public's imagination in the past year following the final episode of the BBC's Blue Planet II, which showed the devastating impact of humans on the world's seas.

The series highlighted the tragic impact this waste is having on marine life, with whales seen to be dying from toxic levels of plastic-related pollution.