Natural Power has completed an update of the Ornithological Cumulative Assessment Model (OCcAM), an offshore wind seabird mortality tool developed to support early-stage impact assessment across the sector. OCcAM is an Excel-based tool that provides indicative predictions of the potential effects of offshore wind farms on seabirds. It is built on established methodologies used in UK environmental impact assessments and habitats regulations assessments, enabling users to generate consistent estimates of collision risk and distributional impacts for multiple seabird species.
Originally funded and developed by SSE Renewables, the tool has now been transferred to the Offshore Wind Industry Council as a free industry resource. The Offshore Wind Industry Council has supported further development to expand its scope, with Natural Power delivering the update on behalf of SSE Renewables and the Offshore Wind Industry Council.
The latest version incorporates nine species relevant to offshore wind projects: lesser black-backed gull, great black-backed gull, herring gull, Manx shearwater, black-legged kittiwake, common guillemot, razorbill, Atlantic puffin and northern gannet.
OCcAM includes embedded biometric parameters and flight height distributions, and allows users to input bird density data and apply different development scenarios. This supports use during scoping, early consultation and optioneering, where indicative assessments are required to inform design decisions and stakeholder engagement.
The tool has been tested with UK statutory nature conservation bodies, which have endorsed its use in pre-application screening. By aligning with established assessment frameworks and promoting consistency, OCcAM is intended to support clearer engagement between developers, consultants, regulators and advisers.
