Europe’s rapid offshore wind expansion is central to the renewable energy transition, but it also constitutes an unprecedented, large-scale transformation of open-ocean habitats. The biodiversity consequences of this ‘industrialisation at sea’ remain poorly understood, especially cumulative and long-term effects that emerge across whole seascapes, which are not captured by today’s largely site-based environmental assessments. UrbanOcean addresses this knowledge gap by reframing offshore wind farms as ‘ocean urbanisation’: a build-out of dense infrastructure networks that can fragment habitats, modify sensory environments (noise, light and electromagnetic fields), and disrupt ecological connectivity, particularly for migratory and pelagic fish adapted to the featureless open ocean. This urbanisation also reshapes access to, and governance of, the sea by changing ownership patterns and constraining traditional resource use, with potential winners and losers among stakeholders, and impacts that can propagate across borders and into coastal communities.
