A Flexible Framework for Assessing the Cumulative Effects of Offshore Wind Energy Activities and Other Pressures on Aerofauna

The offshore wind energy (OSW) industry is pivotal for renewable energy transition and climate resiliency. However, OSW activities may negatively affect aerofauna, contributing to CE from human activities and natural processes. Cumulative effects assessments (CEA) are vital for informed planning and management of OSW activities during regional assessment, site selection, and site evaluation. To reduce impacts on aerofauna, OSW developments should be sited in areas that avoid or minimize cumulative effects (CE). This study presents a cohesive and flexible framework for assessing the CE from OSW activities, other human activities, and natural processes on aerofauna to support decision-making during the initial OSW planning phases. The framework uses a species-based approach, applicable to various receptors, and adapts to available information on ecology, socioeconomics, and pressures. The analytical strategy uses a CE metric to indicate the presence or magnitude of effects from all pressures on receptors. Spatially explicit optimization methods identify OSW site configurations that minimize a CE metric. The framework accommodates alternative pressure scenarios that include foreseeable future human activities and natural processes and can explore the sensitivity of the result to uncertain parameters. Given sufficient spatial information on receptor density, pressure magnitude, and cause-effect pathways, the spatial optimization algorithm can find solutions that minimize population-level impacts from CE. If this ideal standard cannot be achieved due to information gaps, alternative metrics may be used to inform the immediate decision-making process.