Abstract
This report presents data from vessel-based surveys conducted during the winter period 2022/23 at the Kriegers Flak Offshore Wind Farm. The scope of the project is to estimate the abundance and density of wintering Long-tailed Ducks (Clangula Hyemalis) in the Kriegers Flak area, as well as to describe their spatial distribution. The overall purpose is to assess the effect of the existing operational wind farm on the abundance and densities Long-tailed Ducks in the area. The surveys were conducted approximately one year after the commissioning of the wind farm offering the opportunity to investigate potential post construction affects, of an operational wind farm on wintering Long-tailed Ducks.
Post construction surveys of operational wind farms are relatively rare, especially in Denmark, and the data presented in this report can provide valuable information to be applied in future Environmental Impact Assessments (EIA) of offshore wind farms. In particular this concerns the ecological and behavioural responses of Long-tailed Ducks to potential displacement or attraction effects from offshore wind farms in operation. There is a need to gain further insights into the impacts of offshore wind farms on this species, especially given the apparent state of the Long-tailed Duck population in the Baltic Sea, which appears to have suffered a significant and long-term decline according to the IUCN, warranting a downlisting in 2012 - from Least Concern (LC) to Vulnerable (VU) (BirdLife International, 2023).
This study and applied methods are largely inspired by the Nysted/Rødsand II report by the Danish Centre for Environment and Energy (DCE) (Petersen et al. 2018). Kriegers Flak is fairly similar to other sand banks in the Baltic Sea and this study as well as the study from Nysted/Rødsand II wind farm by DCE, serve as case studies for future projects.