The UK government has a commitment to obtain 20% of the UK’s energy from renewable sources by 2020, of which wind energy is likely to form a major part (DECC 2009). Consequently many wind farms are currently under construction and more developments are proposed (e.g. Round 3 zones, Scottish Territorial Waters sites and extensions to Round 1 and Round 2 sites). There is, however, much concern as to the effects that offshore wind developments may have on seabird populations.
Potential areas for development of offshore wind farms include locations that may hold large numbers of seabirds, seaduck and other waterbirds. Both consented and proposed development sites within the North Sea may also overlap the foraging areas of seabirds that are features of protected sites. Offshore wind farms may potentially have an impact on these bird populations through four main effects: (1) displacement due to the disturbance associated with developments; (2) the barrier effect posed by developments to migrating birds and birds commuting between breeding sites and feeding areas; (3) collision mortality; (4) indirect effects due to changes in habitat or prey availability. When assessing the potential effects of proposed wind farms on local bird populations, it is important to establish not only the use that birds make of the proposed wind farm area, but also in the assessment of collision risk, whether they are likely to come into contact with the turbines. The latter is largely determined by the height at which the birds fly, and any avoidance behaviour that they may show towards the turbines.
Before construction is consented, an Environmental Impact Assessment (EIA) is required to identify the possible risks posed by a development. As part of this process, where a ‘likely significant effect’ upon a Natura 2000 site (Special Protection Area, SPA, or Special Area of Conservation, SAC) is identified, an Appropriate Assessment (AA) needs to be conducted, to understand and predict the effects on the feature species found at those sites. SPAs are designated under the European Bird’s Directive (79/409/EEC), which protects sites within the European Union of international importance for breeding, wintering, feeding, or migrating vulnerable bird species. Wind farms have the potential to affect breeding seabirds or wintering waterbirds that are features of SPAs if they forage in areas where wind farms are proposed, or pass through these areas on migration. Thus, it is important to understand the connectivity between features of SPAs with development regions.
This study uses the latest tracking technology to investigate the movements of two seabird species that are features of SPAs – the Lesser Black-backed Gull Larus fuscus and the Great Skua Stercorarius skua.