The Metal Mining Agency of Japan (MMAJ) conducted the eight year project "Environmental Impact Research for Manganese Nodule Mining" from 1989. The overall aim was to reconcile mining of deep ocean manganese nodules with the preservation of the marine environment. The project surveys were carried out in the Japanese mining claim area in the equatorial pan of the north-east Pacific Ocean. The project included baseline surveys, a mining impact experimental, the data analyses, and development of simulation models to estimate the environmental impacts. From these results, methods to evaluate the environmental impacts expected to arise from real mining operations were developed. This paper reports results of the research up to date and recommends some additional areas of future research.
As the global demand for minerals increases, the importance of marine mineral resources is being recognized. Minerals found on deep seabeds are an untouched natural resource of immense potential value to humankind. Deep ocean manganese nodules contain valuable metals such as nickel, copper and cobalt. The project surveys were focused on the surface and bottom water layers. The research included baseline surveys, a mining impact experiment, the data analyses, and development of simulation models to estimate the environmental impacts. In order to evaluate the impacts of the mining operations, an artificial benthic disturbance was carried out in the survey area in 1994. It is known as JET: Japan Deep-Sea Impact Experiment. Subsequent monitoring surveys were conducted in 1994, 1995 and 1996 after the disturbance. The purpose of the research was to establish methods to assess the environmental impacts expected from the real mining. Since the research was almost completed by March 1997, this paper reports the results of "Environmental Impact Research for Manganese Nodule Mining" and suggests further research areas for the future.
