Offshore wind farm foundations as artificial reefs: The devil is in the detail

Climate change and global biodiversity loss call for clean energy production systems with minimised ecological impacts. Offshore wind energy production will become one of the main uses of global marine spaces within next decades. Offshore wind turbine foundations can function as artificial reefs but it is unknown if these capabilities apply to different foundation types. We collected field data on Atlantic cod (Gadus morhua), a species under pressure in the southern North Sea, around three foundation types to assess these capabilities. Catch rates showed that monopile foundations with rock protection on the seabed were able to attract significantly more fish than monopile foundations with sandbag protection and jacket foundations. Fish densities varied on small scales meaning that reef effects were spatially restricted. This implies that offshore wind energy production can be used as tool to combine climate change mitigation with local biodiversity conservation but that a consideration of the wind farm design is required. •Offshore wind farms have been shown to attract fish.•Atlantic cod is an endangered species in the southern North Sea.•Catch rates of Atlantic cod highest around monopiles with rock protection.•Monopiles with sandbag protection and jacket foundations attracted significantly less cod.•Wind farm design can be adapted to meet conservation needs and produce green energy.