The ‘everything is everywhere’ framework: Holistic network analysis as a marine spatial management tool

The North Sea hosts numerous man-made structures, some recently installed and others nearing end-of-life, with decisions about their decommissioning at the centre of current debate. Further there are plans for significant expansion of structures relating in particular to offshore wind energy. Here, using a combination of hydrodynamic modelling, particle tracking, and graph network analysis, we evaluate connectivity under two scenarios: existing structures – releasing particles from cells where structures are currently present – and “everything is everywhere” – releasing particles from every cell in the domain. Additionally, we introduce a Connectivity Importance Index (CII) to assess both current and potential future connectivity within the region. The CII under the ‘everything is everywhere’ scenario revealed cells with high potential connectivity that align with, but also extend beyond, those identified under the existing structures scenario, pointing to potentially valuable regions for future structure placement. The relocatable methodology described in this paper allows for the quantification of potential networks, applicable with or without existing habitat data, offering valuable insights for ecologically coherent marine spatial management strategies. • Connectivity Importance Indices (CIIs) identify connectivity hotspots within a region. • High connectivity regions in the North Sea extend beyond existing structures. • The method quantifies connectivity with or without habitat data and is relocatable. • Insights support ecologically coherent marine spatial management.