International blue carbon project management: Comparing the ideographs, innovation styles, and co-impacts of Japanese blue carbon projects to western countries

Blue carbon ecosystems are increasingly included in national plans to reach net zero emissions worldwide. However, despite recent studies on the sociopolitical and institutional aspects of blue carbon projects, challenges remain relating to project management. For instance, non-English speaking countries, which are underrepresented in blue carbon project studies, both show evidence of successful blue carbon project management and face issues such as insufficient local implementation of protection policies. To address this gap and improve global understanding of blue carbon project management methods, we conducted semi-structured interviews and email questionnaires to identify the typologies of ideographs, innovation styles, and co-impacts of two Japanese blue carbon projects and compare them to two western case studies analyzed using the same typologies. The results showed that Japanese case studies had high stakeholder collaboration between the national government, private corporations, and local entities and placed strong emphasis on co-benefits of restoration rather than focusing on carbon sequestration. This trend contrasts with two Western case studies that focused strongly on carbon sequestration but struggled with policy support and stakeholder inclusion. Japanese case studies showed strong institutional potential, but challenges related to carbon sequestration measurement uncertainties and environmental impacts that impeded restoration still need to be overcome. We attribute inclusion of local stakeholders and organizations to the high levels of blue carbon project implementation in Japan and recommend studies on other Japanese projects and projects in countries underrepresented in research to further understand the strengths and weaknesses of different methods and strategies to adapt to local conditions. • Japanese blue carbon projects focus on collaborations between stakeholders. • Japan exhibits stronger policy and private support for blue carbon than Western cases. • Japan focuses less on maximizing carbon removal compared to US and UK strategies. • Challenges such as water pollution and financial cost hinder carbon capture potential. • Significant blue carbon project information is hidden behind language barriers.