SEAWARDS. Bridging planning rationales to compare maritime spatial planning implications

The increasing use of marine space and the growing complexity of human activities at sea have led to the emergence of Maritime Spatial Planning (MSP) as a key governance instrument for organising maritime uses and addressing environmental, economic, and social challenges. Since the adoption of Directive 2014/89/EU, MSP has been progressively institutionalised across European coastal Member States. However, despite its rapid diffusion, MSP remains characterised by conceptual ambiguity and uneven implementation, particularly in relation to its spatial implications and its connection with established spatial planning traditions. Within this context, the research investigates MSP as an evolving form of spatial governance, analysing its nature as a process, a conceptual approach, and an operational tool. The study aims to understand how spatial and strategic planning principles contribute to explaining MSP’s development and to interpreting its implications across national and sub-national scales. Given the complexity of marine environments and governance systems, MSP evolves through diverse institutional configurations rather than following a single, consolidated model. The research adopts an interpretive and comparative methodology, combining theoretical analysis with the examination of European policy frameworks and national planning systems. This approach is complemented by the analysis of three case studies, Italy, Spain, and Ireland, through document review and semi-structured interviews with institutional and technical actors. The comparison allows for the exploration of how conceptual approaches are translated into planning practices and how these vary across contexts. The findings show that MSP primarily produces institutional effects, contributing to the establishment of coordination mechanisms, governance structures, and planning procedures. Its capacity to generate measurable spatial and socio-economic outcomes remains limited, reflecting its early stage of development. Significant variation emerges across national contexts, shaped by differences in scale, scope, and governance arrangements, leading to the coexistence of regulatory and strategic planning models. The research highlights the coexistence of multiple conceptual approaches and the partial integration of planning tools within MSP frameworks. While tools support data management, stakeholder engagement, and conflict mediation, they rarely function as drivers of spatial design. A key contribution of the thesis lies in bridging MSP with spatial planning theory, identifying lessons related to strategic selectivity, place-based approaches, and adaptive governance. At the same time, the marine domain offers insights for rethinking planning under conditions of uncertainty and fluid spatial boundaries. Overall, the thesis contributes to the understanding of MSP as a dynamic and evolving planning system. It argues that MSP should be interpreted as an extension of spatial planning into the marine domain, capable of reshaping planning practices and governance systems in response to emerging spatial and environmental challenges.