Abstract
Some Cumulative Effects Assessments (CEAs) screen out projects where a quantitative assessment of the number of animals impacted is not available (i.e. no EIA is available). Other CEAs acknowledge that offshore wind farm (OWF) projects should be considered and use a set of assumptions to estimate the number of animals disturbed. The purpose of this case study was to demonstrate (using iPCoD population modelling) the difference in a quantitative CEA depending on whether projects without an EIA are included in the assessment or not. Two scenarios were run in iPCoD to model the population level effects of disturbance:
- Scenario 1: EIA Projects Only - all planned OWF located in the North Sea MU that have an EIA, and
- Scenario 2: All Projects -all planned OWF located in the North Sea MU both with and without an EIA, using an effective deterrence range (EDR) and the SCANS IV density to estimate the number of impacted animals for projects without an EIA.
Despite substantially different inputs in terms of the number of projects and the number of piling days between the two scenarios, the population level results were almost identical. The reason for this is apparent when comparing the number of animals potentially disturbed by each project in the two scenarios. The number of animals predicted to be impacted for projects without an EIA are vastly smaller than those predicted in EIAs. Therefore, the results from the two different methods are markedly different and incompatible, and caution used when comparing. This needs to be taken into consideration when reviewing CEAs, and Regulators and Statutory Advisors need to provide clear guidance as to what methods should be used and how to best account for projects without an EIA.