TOKYO - Japan's easternmost island of Minamitori, which is currently being assessed as a potential disposal site for highly radioactive waste, could lose its conservation value due to on-site surveys and construction required for the process, a private local research institute has warned.
Since the central government proposed a preliminary survey for Minamitori Island in March, the Institute of Boninology in Ogasawara village, administered as part of Tokyo, has been independently collecting and publishing information on the island's natural environment, with more than 120 academic papers to date.
The collection highlights the island's exceptional conservation value, documenting numerous rare species of fish, plants and other wildlife.
The preliminary survey on the suitability of Minamitori Island as a permanent nuclear waste disposal site -- the initial part of a three-stage, 20-year process -- began last month.
The Nuclear Waste Management Organization, which is overseeing the project, says the survey, based on published geological sources, mainly examines strata and mineral resources, adding that "ecosystems are not included in the evaluation items."
Founded on Chichijima Island in 2000 to help protect the ecosystem of the entire Ogasawara Islands in the Pacific, the institute conducts wildlife research and conservation work.
"Our current knowledge alone already demonstrates the (Minamitori) island's conservation value. The ecosystem should be thoroughly studied before human access to the island increases," said the institute's vice director Hajime Suzuki.
Among the species highlighted is a rare angelfish discovered around Minamitori Island in 1987, whose polka-dot pattern changes as it matures and which can undergo sex reversal from female to male. The waters around the island may be one of its main habitats.
In the island's central area grows the Togemiudonoki, or the grand devil's-claws, a flowering tree in the Bougainvillea family found mainly in Australia and the South Pacific that occurs nowhere else in Japan.
A 2022 ornithological survey also confirmed a white tern parent and chick, marking Japan's first recorded breeding of the species in 120 years.
The selection process for the final disposal site for highly radioactive waste consists of a preliminary survey, preliminary investigation and detailed investigation.
The institute warns that the preliminary investigation involves on-site drilling, while the detailed investigation would lead to the construction of underground facilities, potentially causing major environmental changes.
Suzuki is calling for locally led field studies to be carried out urgently.
