The impact of humans is reaching some of the deepest corners of the Pacific Ocean, according to new research.
A study, led by Alan Jamieson of Newcastle University in England, sampled amphipods - small crustaceans - found in the Mariana and Kermadec trenches of the Pacific Ocean, which are more than 10 kilometers deep and seven kilometers apart.
The team's results are sobering: high levels of Persistent Organic Pollutants, otherwise known as POPs, were found in the fatty tissue of the amphipods.
According to a release from the university, the POPs found included polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), which are known to be used as electrical insulators and flame retardants.
The team included researchers from Newcastle University, the University of Aberdeen and the James Hutton Institute. Their findings were published in Nature Ecology & Evolution.
"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," Jamieson, from Newcastle University's School of Marine Science and Technology, said in a statement on Monday.
"In fact, the amphipods we sampled contained levels of contamination similar to that found in Suruga Bay, one of the most polluted industrial zones of the northwest Pacific," Jamieson added.
"What we don't yet know is what this means for the wider ecosystem and understanding that will be the next major challenge."
PCBs were banned in the 1970s but are still being found in the environment today, Newcastle University said, due to the fact they are "invulnerable to natural degradation."
"The fact that we found such extraordinary levels of these pollutants in one of the most remote and inaccessible habitats on earth really brings home the long term, devastating impact that mankind is having on the planet," Jamieson added. "It's not a great legacy that we're leaving behind."