Good work, humans! There are now thousands of pieces of human-made trash lurking at bottom of the world’s deepest waters. There are even plastic bags at depths of 10,898 meters (35,755 feet, or 6.7 miles) on the floor of the Mariana Trench, the world’s deepest ocean trench.
These findings come from a new study published in Marine Policy by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in Yokosuka. They collected huge amounts of data and images from deep-sea submersibles and remotely operated vehicles (ROV) to find out the scale of the deep-sea plastic problem across the world’s seas.
Turns out, it isn’t good. Although many of the world’s oceans were explored, the majority of the records are from the western North Pacific. Here, they discovered there’s up to 335 items on every 1 square kilometer (0.4 square miles) of the seabed.
During thousands of dives between 1983 and March 2017 across the oceans, the researchers noted at least 3,425 instances of debris at depths of over 6,000 meters (19,685 feet). Around a third of this debris was plastic products that take hundreds and hundreds of years to biodegrade. Metal, rubber, fishing gear, glass bottles, and other human-made crap also contributed to the collection. Of course, this is just the stuff that was caught on camera, the reality is likely to be considerably worse.
You can view an extensive catalog of the deep-sea debris in this JAMSTEC online database.
Most worryingly, there is also a plethora of fascinating deep-sea creatures that live alongside all of that garbage. Some of the images show plastic alongside starfish, fish, and other marine creatures.
Previous studies have found that plastic can now be found in the stomachs of sea creatures in all six of the ocean's known deepest areas. Researchers looked at 90 crustaceans that live at depths of 7 to 10 kilometers (4.3 to 6.2 miles), and discovered their intestinal tracts contained numerous types of synthetic fibers including Rayon and Lyocell, which are microfibers used in the production of Nylon, polyamide, polyethylene, and PVC.
“This study shows that plastic debris, particularly single-use products, has reached the deepest parts of the ocean,” write the new study authors.
"The highlight of this study was the ubiquitous distribution of single-use plastic, even to the greatest depths of the Mariana Trench, indicating a clear link between daily human activities and remote environments where no direct human activities occur," they added. "The current study suggests that all pelagic, mesopelagic, and deep-sea species in the western North Pacific may be at risk.”
Fortunately, many countries have caught wind of the problem and have started to implement some tough new policies to curb the problem, such as the UK's highly successful plastic bag tax.