Alarmingly high levels of PCBs measuring up to 905 ng/g were discovered in amphipods living in the trench and on the floor of the west Pacific Ocean, at depths of more than 10,000 meters. Ocean pollution is undoubtedly penetrating the deepest parts of the ocean. It is possible that PCBs reached the hadal zone through the food chain, when marine organisms mistakenly consumed microplastics floating in the ocean that had condensed PCBs adhering to their surface. There is hope for further advances on research in Japan regarding the biogeochemical cycle in the hadal zone, not only to strengthen efforts to stop marine pollution, but also as the country which holds the largest hadal EEZ in the entire world.