Developing Transboundary Marine Spatial Planning: Opportunities and barriers for the Greater North Sea Basin Initiative

Marine Spatial Planning is typically a matter of national sovereignty, but growing cross-border marine activities are creating pressure for more coordinated transboundary approaches. However, such Transboundary Marine Spatial Planning (TMSP) efforts remain largely informal, temporary and voluntary, begging the question why more formal and enduring collaborations have struggled to materialize. This study aims to identify opportunities and barriers shaping the development and mode of collaboration of novel TMSP on the North Sea. A qualitative research methodology is adopted, combining a systematic literature review with an in-depth case study of the Greater North Sea Basin Initiative, based on participant observation. This initiative brings together nine North Sea countries to explore the creation of a regional platform for spatial integration of marine activities. The literature review identifies six categories that may function both as opportunities and barriers: resource availability, data and knowledge, the alignment of national institutional frameworks, (geo)political dynamics, existing transboundary relations and institutions, and stakeholder participation. The case study findings reveal that, while various opportunities legitimize and support the initiative’s development, key concerns – particularly over national sovereignty and institutional ambiguity of sea basin-level governance – limited the potential formality of collaboration. As a result, the initiative is evolving as an informal, voluntary platform for agenda-setting and early dialogue. The study concludes that although formal TMSP remains unlikely on the short-term, fostering informal collaboration already allows for more structured regional coordination as spatial and geopolitical tensions increase, while it may also be a stepping stone to possible future degrees of formalization. • Transboundary Marine Spatial Planning is largely limited to voluntary efforts. • The Greater North Sea Basin Initiative is a promising example of TMSP. • Barriers include national sovereignty considerations and institutional ambiguities. • Barriers steer the development of TMSP is to an informal platform for dialogue. • Current, more informal efforts are crucial for intensifying TMSP at later stages.