海底鉱物資源開発に関わる環境調査と影響評価の現状と展開

抄録

Deep-sea environments are faced with cumulative effects of many human activities, e.g. accumulation of plastics, overwhelming fishing and resource exploitation, heavy maritime transportation, and effects from climate change. Recently, growing interest in deep-sea mining enhances the activities of engineering development on seabed mining and environmental monitoring, and exploration of mining sites within States Exclusive Economic Zones (EEZ) or in areas beyond the limits of national jurisdiction. Since 2010, attention paid to potential environmental impacts caused by deep-sea mining has been increased, and many workshops and research conferences have been held. In the Western Pacific Ocean, the Nautilus Minerals Ltd. has announced that the sea mound located in Papua New Guinea will be a first site likely to be commercially exploited polymetallic sulfide deposit. The Japan Oil, Gas and Metals National Corporation (JOGMEC) conducts a feasibility project for seabed mining in the Okinawa Trough. In 2015, the leaders’ declaration from the G7 summit in Germany identified the conducting of Environmental Impact Assessment (EIA) and scientific research as a priority issue for sustainable development of deep-sea mining. The EIA protocol developed for deep-sea mining is recognized that it will be a practical component for ensuring effective management and protection of ocean ecosystems. The development of EIA protocols is started in Japan as a national project. This paper describes the current situation of technologies concerning deep-sea environmental assessment and monitoring on seabed mining, and technical background of multidisciplinary approaches for deep-sea environmental survey.