[M-IS20] Ocean Plastics, an earth science perspective

[MIS20-P02] Deep sea Macro plastics in the Northwestern Pacific Ocean

*Tomoaki Kitayama¹, Takashi Hosono¹, Hideaki Saito¹ (1.Japan Agency for Marine-Earth Science and Technology)

Keywords:Deep-sea debris, Marine litter, Seafloor litter, Macro plastics, Northwestern Pacific Ocean

Enhancement of marine litter knowledge is essential to address the challenges of SDG14 such as marine pollution and conservation of sea and marine resources including biodiversity. However, information on seafloor litter is limited in marine litter studies. This is because it is not easy to approach the seafloor, and in order to clarify the life cycle of marine litter and the so-called Missing Plastics (99% out of all plastics that has entered into the ocean are missing), it is necessary to accumulate knowledge and information on seafloor litter. The Global Oceanographic Data Center (GODAC) of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has published a “deep-sea debris dataset” using videos and photos taken during deep sea research in 2017, which data on categories, condition (accumulation point and drifting, etc.), and environments (sea bottom sediments and activities of organisms near the litters) of deep sea litter. A scientific paper based on this dataset has reported on distribution of plastic waste in the deep sea over 6000-m deep (Chiba et al., 2018). We also have been accumulating knowledge and information on seafloor litter of the northwestern Pacific Ocean, which has one of the most complex topographical characteristics in the world, with the triple junction and the world’s deepest seafloor, the Mariana Trench.
In this presentation, we will present a re-analysis of the spatial distribution and characteristics of seafloor litter of the northwestern Pacific Ocean using the “deep-sea debris dataset” with additional data from 2017 to 2021. Moreover, we will discuss how these data should be accumulated and provided to contribute to marine litter researches.


S. Chiba, H. Saito, R. Fletcher, T. Yogi, M. Kayo, S. Miyagi, M. Ogido, K. Fujikura,
Human footprint in the abyss: 30 year records of deep-sea plastic debris
Marine Policy (2018), 10.1016/j.marpol.2018.03.022