In connection with the problem of Chinese ships conducting unauthorized marine research in Japan’s exclusive economic zone (EEZ), it was learned on July 22 that Chinese marine research ships had continually been taking soil samples from the seabed over a wide area. This was the first time that details of their activities have been revealed. China is advocating the extension of its continental shelf, which would give it the right to develop underwater resources. It is believed to be conducting soil analysis to substantiate the legitimacy of its claim.
According to the Japan Coast Guard (JCG), Chinese marine research vessels conducted unauthorized surveys from early to mid-June and from late June to early July. Such activities also took place on a daily basis near Kuba Island and in waters north of Taisho Island from July 10-15. On certain days, three research vessels were engaged in such activities simultaneously in waters near Okinawa.
According to several senior government officials, the Chinese ships introduced bottom samplers, which operated around the clock in their recent surveys. These devices lifted soil once every 30 minutes. They responded to the JCG’s demand for them to stop the surveys by asserting that the surveys were being conducted with the Chinese government’s permission.
According to the Agency of Natural Resources and Energy, which oversees seabed resources, it is unlikely for metallic mineral deposits to be found in the seabed near the Senkaku Islands. Therefore, it is strongly believed that the surveys were unrelated to resources but were meant to determine whether soil in the seabed in this area came from China’s rivers.
China wants to extend the maritime delimitation of its EEZ in the East China Sea to seize interests in Japan’s EEZ. While Japan regards the median line between the two countries’ coastlines as the delimitation of their EEZs, China asserts that its continental shelf extends from its coast to the Okinawa Trough in waters near Okinawa. China submitted a proposal to extend the outer limit of its continental shelf to the UN Commission on the Limits of the Continental Shelf in 2012. It is reckoned that it is seeking to use sediments from the Chinese mainland to support its proposal to extend its continental shelf.