It was believed that the deepest parts of the world's waters remain untouched by human impact, but new research proved this is no longer true. A new study published in Nature Ecology and Evolution was a stark reality check, revealing that man-made pollutants are already present in the most remote depths of the oceans.
Scientists from the University of Aberdeen and the James Hutton Institute in the United Kingdom discovered that pollutants have already contaminated marine organisms living in the Mariana Trench in Western Pacific and Kermadec Trench in New Zealand, according to a report from Washington Post.
The team used "deep-sea landers" to capture amphipods that they later tested for two specific chemical pollutants: polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The former has been banned in the United States, while use of the latter has already been reduced, but both were found to still be present in all species of amphipod in both trenches and in depths up to 10,000 meters.
Mariana is particularly polluted with a concentration of PCBs that's around 50 times greater than in China's Liaohe River, known as one of the country's most polluted waterways. It's roughly as polluted as Japan's Suruga Bay, which is located in a very industrialized area.
"We still think of the deep ocean as being this remote and pristine realm, safe from human impact, but our research shows that, sadly, this could not be further from the truth," study leader Alan Jamieson of Newcastle University in the UK told The Guardian.
The authors suggested that the pollutants in the Mariana Trench came from the "great Pacific garbage patch." They also point out that ocean currents can carry garbage from all over the world.
"The fact that we found such extraordinary levels of these pollutants really brings home the long-term, devastating impact that mankind is having on the planet," Jamieson concluded.