OCcAM: A tool for rapidly assessing impacts of offshore wind farms on seabirds

Offshore wind energy generation has a key role in reducing reliance on fossil fuels and mitigating climate change. However, it also has the potential to negatively impact the environment, including seabird populations. Quantifying and minimising impacts of wind projects on seabirds is necessary for ensuring compliance with environmental legislation and safeguarding populations. However, the timescales and complexity involved in assessment processes can limit the extent to which estimates can be leveraged towards balancing environmental impact and energy generation. OCcAM is a simple, user-friendly and transparent industry-developed tool allowing rapid assessment of impacts on seabirds from offshore wind developments. Mortality rates of five seabird species are estimated using two UK industry-standard models: the Band collision risk model which predicts fatal collisions with turbine blades, and the matrix-based displacement approach that predicts mortalities associated with distributional responses to the presence of a wind farm. The tool supports simultaneous analysis of up to three input parameter sets and predictions can be expressed as a percentage of a focal population. OCcAM allows auditable analyses to be run quickly and easily with no requirement for specific technical expertise, making it accessible to all stakeholders. It presents a variety of opportunities to facilitate ornithological assessment at strategic to project-specific scales. Here we demonstrate three potential applications of OCcAM: (1) predicting the cumulative impact of Scottish offshore wind farms upon protected seabird populations, (2) updating fatality estimates calculated for worst-case consented values using as-built input parameters and (3) optioneering of project design parameters relative to seabird risk.