Life‐cycle impact assessment of offshore wind energy development on migrating bird diversity in the North Sea

Abstract As offshore wind energy development increases, it is vital to rapidly assess the cumulative impacts to biodiversity, particularly for migratory species that could be impacted across multiple sites. Life‐cycle assessments (LCAs) are a useful tool for assessing and comparing cumulative effects over a large scale and are frequently used for decision‐making in industry. We have adapted the LCA methodology to assess collision, disturbance and barrier impacts of offshore wind energy developments in the North Sea on migrating birds from Norway by 2030. The potentially disappeared fraction of species (PDF)—a measure of the potential loss of species richness in an area—for collision, disturbance and barrier impacts was calculated for birds on migration within migration groups, relative to wind farm energy production in GWh. Distributions were modelled based on ring recoveries from countries surrounding the North Sea Basin, using a Brownian bridge approach. Wind farm developments in the North Sea were found to have the greatest impact on migrating waterbirds and soaring birds. For most groups, potential impacts from disturbance and barrier effects were higher than impacts caused by collision. Maps highlight where cumulative PDF values for combined collision, disturbance and barrier effects are expected to be highest, both by group and for all migratory species combined. Synthesis and applications . Our findings stress the potential cumulative impacts to migrating birds from large‐scale offshore wind energy development in the North Sea by 2030 relative to wind farm energy production. The combination of long‐term bird ringing data and LCAs, which are already widely used by industry in other contexts, could be a useful tool for comparing potential impacts across proposed wind farm sites for environmental impact assessments and national strategic environmental assessments. The LCA methodology presented here could be adapted further to rapidly assess impacts of other types of energy developments on a wide range of migratory species.