A review of biofouling characteristics and issues for offshore renewable energy industry

The development of offshore renewable energy (ORE) is accelerating to reach global decarbonisation objectives, but it faces technical and ecological challenges, including biofouling. This review synthesises current knowledge on biofouling colonising ORE structures, focusing on: 1) its technical impacts (increased hydrodynamic drag, corrosion, decreased component lifespan), and 2) its environmental impacts (modification of habitat, reef effect, non-native species dispersal). Special focus is given to floating systems, such as floating wind turbines, where biofouling significantly influences mooring lines and dynamic cables. Despite increasing interest in the field, many uncertainties remain, notably the lack of <i>in situ</i> offshore data, limited understanding of biofouling-structure interactions, and absence of standardised measurement protocols. The review discusses main knowledge gaps in offshore fouling dynamics and proposes future research perspectives to improve maintenance strategies and environmental management. Understanding these processes is essential for the long-term sustainability of ORE technologies and their integration into marine ecosystems.