Consensus building among local stakeholders is vital for the success of the proposed initial commercial marine renewable energy (MRE) projects in Japan. Even though the literature on stakeholder acceptance highlights the importance of creating local benefits and co-creation options, very few studies and almost no empirical data have been published on the application of non-monetary benefit creation schemes in the context of MRE. Hence, the purpose of this study was to systematically evaluate the possible co-existence options available for Japan’s MRE projects through data collected from interviews and questionnaire surveys in two development sites in Nagasaki and Kitakyushu in Southern Japan. To overcome the limitations of data unavailability and uncertainty, the Dempster Shafer Analytic Hierarchy Process (DS-AHP) was used for evaluating the best co-existence strategy out of five potential options. The results indicate that local fisheries prefer the oceanographic information sharing option whereas most of the other stakeholders prefer using local resources to construct and operate the power plant, creating business involvement opportunities for the local community. Analysis of stakeholders’ decision behaviors suggests that perceived impacts, knowledge, and values influence the preference decision. In addition to the validation of stakeholder preference of the previously proposed co-existence options with empirical data, this study provides a robust method to further evaluate the potential options with the availability of new data.

The technology of generating an artificial upwelling by constructing a seabed mound to increase the primary production is being examined off Ikitsuki Island, Nagasaki, Japan. A numerical simulation model is being developed in order to evaluate the effects and environmental influence of the artificial seabed mound. At the first stage of the modeling, tidal current is calculated for the coastal region including the artificial upwelling area. Since most of the boundaries of the computational domain are open to the ocean, it is necessary to give incoming tidal wave all over them, which is not easy because of complicate topography. A newly developed inverse method using the observation data at tidal stations along the coastline was applied to determine the boundary conditions of tide. The calculated tide by the method agreed fairly well with the observation data. Currents near the seabed mound was also investigated, whose result is indicated that internal wave induced by the mound makes the mixing larger.