Relational values across land–sea interactions: Insights from a forest–river–ocean nexus watershed in northeastern Japan

Relational values have gained increasing attention in sustainability science and environmental governance because they move beyond the instrumental–intrinsic dichotomy and support more pluralistic approaches to environmental decision–making. However, while land–sea interactions are increasingly emphasized in marine governance, their socio–ecological dimensions across source–to–sea watershed systems remain insufficiently understood, particularly in non-Western contexts. This study examines relational values within a small watershed characterized by a tightly coupled forest–river–ocean nexus in northeastern Japan. Based on semi–structured interviews with local stakeholders in the Hei River watershed and qualitative thematic analysis guided by the relational values syntax framework, the study identifies key relational values associated with the forest–river–ocean system and examines how they shape local environmental perceptions, resource–use practices, and stewardship behaviors. These findings highlight the importance of integrating place-based relational values into marine and watershed governance frameworks. Such integration can support more coherent land–sea policies that align with local understandings of ecosystem connectivity and strengthen both policy effectiveness and social legitimacy.