Nuclear waste survey threatens ecosystem of Japan's Minamitori Island

A private research institute has warned that field surveys and construction linked to the selection of a permanent high-level radioactive waste disposal site could diminish the conservation value of Minamitori Island, Japan’s easternmost territory, which is renowned for its unique biodiversity. The initial feasibility survey for the island began last month, marking the first stage of a three-step selection process expected to take 20 years before a final disposal site is designated. The Nuclear Waste Management Organization of Japan, which oversees the project, stated that the survey is based on published geological sources and focuses on rock strata and mineral resources, emphasising that ecosystems are not included in the evaluation items. This stance has alarmed the Institute of Boninology, a research body based in Ogasawara Village, Tokyo. Since the central government proposed the preliminary survey in March, the institute has independently gathered and published information on the island’s environment, compiling over 120 academic papers documenting rare fish, plants, and wildlife. Hajime Suzuki, the institute’s deputy director, argued that existing data already demonstrates the island’s high conservation value and that its ecosystem must be studied thoroughly before human access increases. Scientific findings support this view, including the discovery of a rare angelfish around the island in 1987, which changes its spot patterns as it grows and can change sex from female to male. The island’s central area hosts the Togemiudonoki, or grand devil’s-claws, a flowering tree from the Bougainvillea family typically found in Australia and the South Pacific, and not seen elsewhere in Japan. A 2022 ornithological survey also confirmed the breeding of white terns on the island for the first time in Japan in 120 years. The Institute of Boninology cautioned that environmental risks extend beyond the initial survey, as the preliminary investigation will involve on-site drilling and the detailed investigation could trigger underground facility construction, leading to significant environmental changes. Suzuki urged that locally led field research be conducted promptly to ensure all ecological values are documented and considered before further development proceeds.