Experts at Newcastle University have discovered that even the deepest parts of our planet are polluted. Animals from six of the deepest oceans on Earth have been found to contain man-made fibres and plastic in their stomachs.
The study, led by Newcastle University’s Dr Alan Jamieson, uncovered evidence that not only have plastics now reached the deepest chasms of our oceans but they are also being ingested by the animals that live there. The team tested samples of crustaceans found in the ultra-deep trenches that span the entire Pacific Ocean – the Mariana, Japan, Izu-Bonin, Peru-Chile, New Hebrides and Kermadec trenches. The team uses deep-sea ‘landers’, developed by Dr Jamieson, which free-fall to the ocean floor and carry out a variety of monitoring and sampling tasks.
“The results were both immediate and startling,” says Dr Jamieson. “This type of work requires a great deal of contamination control but there were instances where the fibres could actually be seen in the stomach contents of the creatures as they were being removed. This is a very worrying find. Isolating plastic fibres from inside animals from nearly 11 kilometres (7 miles) deep shows the extent of the problem.”
An estimated 300 million tonnes of plastic now litter the oceans, with more than 5 trillion plastic pieces weighing over 250,000 tonnes currently floating on the surface. “Litter discarded into the oceans will end up washed back ashore or sinking to the deep-sea. There are no other options,” explains Dr Jamieson.
Ultimately, the degradation and fragmentation of plastics will result in the material sinking to the underlying deep-sea habitats, where opportunities for dispersal become ever more limited: “Deep-sea organisms are dependent on food raining down from the surface which in turn brings any adverse components, such as plastic and pollutants, with it. The deep-sea is not only the ultimate sink for any material that descends from the surface, but it is inhabited by organisms well adapted to a low food environment and which will often eat just about anything.”
The team’s findings were revealed as part of Sky Ocean Rescue, a campaign to raise awareness of how plastics and pollutants are affecting our seas and their ecosystems. “The deep-ocean is highly connected to the surface waters,” says Dr Jamieson. “The number of areas we researched, and the thousands of kilometre distances involved, shows it is not just an isolated case – this is global. Understanding what this means for the wider ecosystem will be the next major challenge.”