A NUMERICAL MODEL FOR ENVIRONMENTAL IMPACT ON MARINE ORGANISMS FOR SEAFLOOR RESOURCES DEVELOPMENT

摘要

The exclusive economic zone (EEZ) of Japan has a very wide area due to a lot of islands in the Japanese Archipelago. Recently, the development of power generation facilities, food production facilities, and the natural resources in the Japanese EEZ are planned. As the worldwide supply and demand of mineral resources are being tight, the technology for effective exploitation and the use of mineral resources in the EEZ will become a key for sustainable development in the Japanese industry. Prior to development of marine mineral resources, it is necessary to evaluate its environmental impact on the water column and seafloor of ocean. However, the environmental evaluation method for open ocean has not been established yet. Then, we are developing the environmental impact prediction model for the seafloor mineral resources development in deep sea area with the consideration of benthic organisms. This model can estimate the impacts of excavating seafloor and sedimentation of particles on marine organisms using an ecosystem model. In addition, the influence of an increase in dissolved oxygen on bacteria caused by the discharging of oxygen-rich waste water at seafloor, is considered in this model. The ecosystem in this model includes benthic organisms, zooplankton, bacteria, particulate organic matter and dissolved oxygen as the components. This paper introduces the calculation case using the prototype model.