Abstract
To inform the consenting process, the potential impacts on seabird populations of the key effects associated with renewable energy developments are assessed through an Environmental Impact Assessment (EIA). When preparing applications for Nationally Significant Infrastructure Projects (NSIPs) in England or Wales, or for equivalent national developments or major developments in Scotland and Northern Ireland, developers are legally required as part of the Habitats Regulations Assessment or Appraisal (HRA) process to consider if the project is likely to affect European protected sites.
If Likely Significant Effects (LSEs) on the features of a European protected site cannot be ruled out after HRA screening, the HRA report provided with the application should enable the competent authority to then carry out an Appropriate Assessment (AA). The purpose of the AA is to ascertain whether or not there are any Adverse Effects On Integrity (AEOI) on the relevant sites. These assessments determine whether populations within the site may be negatively affected by a development, for seabirds, typically through the use of demographic models.
The demographic models used as part of assessments require baseline information on the abundance and demographic parameters of the populations concerned. However, it is unclear the extent to which the demographic data used in these models relate to the specific sites considered in assessments.
It is also unknown whether existing monitoring of seabird populations at a colony level has sufficient statistical power to detect changes of the magnitudes predicted in response to the effects associated with offshore wind farms.
We reviewed AAs that have been carried out in relation to 21 consented, but not yet fully operational, offshore wind farms, to identify seabird populations of Special Protection Areas (SPAs) where LSEs in relation to offshore wind farms could not be ruled out by HRA screening prior to AA. Consequently, the populations selected reflect those for which monitoring might be required to detect the impacts associated with new offshore wind farms as they become operational.