First Meeting With 4 Prefectural Governors on Comprehensive ‘Setouchi Oceans X’ Project to Address Marine DebrisAgreement reached to carry out large-scale cleanup project by 4 prefectures, targeting 86 tons of debris to be collected annually

As part of the Setouchi Oceans X project to find comprehensive measures to address the issue of marine debris, The Nippon Foundation Chairman Yohei Sasakawa and the governors of the project’s four participating prefectures (Okayama, Hiroshima, Kagawa, Ehime) held their first top-level meeting on April 15. They reviewed the project’s accomplishments to date, discussed its future direction, set new targets based on the current situation, extended the term of the project, and agreed that the four prefectures would cooperate in a large-scale cleanup activity.

Agreement details

  • Extend the Setouchi Oceans X project to March 2028
  • The four prefectures will jointly carry out a large-scale cleanup activity in the summer of 2025

New target

  • Create a framework for the ongoing collection of 86 tons of debris annually (to recover at least 344 tons by March 2028)
Photo of Okayama Governor Ryuta Ibaragi, Hiroshima Governor Hidehiko Yuzaki, The Nippon Foundation Chairman Yohei Sasakawa, Kagawa Governor Toyohito Ikeda, and Ehime Governor Tokihiro Nakamura
Photo following the signing (left to right): Okayama Governor Ryuta Ibaragi, Hiroshima Governor Hidehiko Yuzaki, The Nippon Foundation Chairman Yohei Sasakawa, Kagawa Governor Toyohito Ikeda, Ehime Governor Tokihiro Nakamura

The Nippon Foundation and the four prefectures bordering the Seto Inland Sea launched the Setouchi Oceans X project in December 2020 to address the issue of plastic and other marine debris. The Seto Inland Sea is a scenic waterway bordered by Japan’s main island of Honshu and the island of Shikoku, and the location was chosen because the Seto Inland Sea receives relatively little inflow of debris from the outside ocean. The project was originally scheduled to last for roughly five years, from fiscal 2020 to fiscal 2024 (April 2020 to March 2025). Research conducted by The Nippon Foundation* found that the amount of plastic debris generated by the four prefectures totaled approximately 388 tons annually, while the amount collected by local governments and other entities was roughly 302 tons and by Setouchi Oceans X was roughly 26 tons, for a total of approximately 328 tons. This meant that the difference, roughly 60 tons of marine debris, was flowing into the sea each year.

  • * Journal of Coastal Zone Studies, Vol. 36, Issue 2 (2023)

Given this situation and looking forward, the participants decided to extend the project by three years, through fiscal 2027 (ending March 2028). During that time, the project aims to establish a framework to collect this additional 60 tons of debris, collecting a total of 86 tons from rivers and the sea annually on an ongoing basis. At the same time, the project will also work to curtail inflows from floats and other fishing equipment, with the aim of a turnaround to a situation where the amount of debris decreases every year. As part of this effort, the four prefectures plan to hold a large-scale cleanup event in the summer of 2025.

As of March 2024, the project had collected a total of roughly 78 tons of debris with 120,000 participants on an aggregate basis. From April 2024 through the extended period to March 2028, the project expects to collect at least approximately 344 tons of debris with roughly 200,000 people participating.

Going forward, The Nippon Foundation will continue to work to pass on the ocean’s bounty to the next generation by building more broad-based cooperative networks that go beyond local governments and creating models for addressing ocean debris and moving closer to a recycling-oriented society.

“Schematic diagram showing situation regarding ocean debris in the project’s four prefectures. From “Balance of Plastic Litter Inflow from Land, Generation in Sea Area and Collection in Four Prefectures in the Seto Inland Sea,” Journal of Coastal Zone Studies, Vol. 36, Issue 2 (2023). 303 tons of debris flows into the ocean from land. An additional 85 tons is generated at sea. The total that flows into the ocean and is created at sea is 388 tons annually. Of the debris that is collected on land and at sea, 302 tons is collected primarily by public entities including the Ministry of the Environment, the Ministry of Land, Infrastructure, Transport and Tourism, the Ministry of Agriculture, Forestry and Fisheries, the Fisheries Agency, cities and towns in each prefecture, port and harbor administrators, and fisheries cooperatives (annual average for the five years from fiscal 2017 to 2021). An additional 26 tons is collected by the Setouchi Oceans X project (which has collected a total of 76 tons over the three years from fiscal 2021 to 2023, for an annual average of 26 tons). The resulting shortfall is 60 tons annually (excluding inflow into the area from outside and outflow from inside the area outside). The survey therefore made two figures clear: that the Setouchi Oceans X project should collect roughly 86 tons annually (388 tons minus 302 tons); and that the current shortfall that needs to be collected additionally is approximately 60 tons (86 tons minus 26 tons).”
Current situation regarding ocean debris in four prefectures

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