The study “Auks in the German North Sea: Effects of Offshore Wind Farms”, commissioned by the German Offshore Wind Energy Association, examined the effects of wind farms on the distribution of guillemots and razorbills in the German North Sea.  

In their analysis, the renowned environmental institutes IBL Umweltplanung and BioConsult SH placed particular emphasis on possible seasonal, regional and inter-species differences. They draw on a very comprehensive and high-quality eight-year data set from airborne and ship-based surveys collected in 22 offshore wind farms and other monitoring projects between 2014 and 2021. 

The researchers regularly found guillemots and razorbills in wind farms. However, avoidance behavior towards wind farms was also observed seasonally and regionally. In winter (October to February) the avoidance effect was low for guillemots and not detectable for razorbills. In autumn (July to September) it was more pronounced for both species within a radius of several kilometers.  

The avoidance effect is a calculated value and means that statistically fewer animals are present within this distance from offshore wind farms. The observed density of the occurrence of animals increased again even at a short distance from the wind farms.  

The results show strong seasonal and regional differences in the behaviour of guillemots and razorbills near offshore wind farms. In comparison to other studies, a blanket large-scale avoidance could not be confirmed.  

Further research is needed to determine which other factors play a role in the animals' increased avoidance behavior in the autumn months and what role the size of the wind turbines and their distances between them play. This was not investigated in this study.  

Background:  

The German North Sea is an important feeding and resting area for the common guillemot and razorbill seabird species, which also breed on Heligoland. In winter, large populations of these auks from other breeding colonies also use the area, especially from Great Britain. 

The study “Auks in the German North Sea: Effects of Offshore Wind Farms. A study into Common Guillemot (Uria aalge) and Razorbill (Alca torda) distribution based on aerial and ship survey data in the German North Sea”. here accessible.

The study was commissioned by the German Offshore Wind Energy Association eV with funding from member companies BP Europa SE, CEID ApS, CI V Coöperatief UA, EnBW Energie Baden-Württemberg AG, Ørsted, OWP Gennaker GmbH, RWE Offshore Wind GmbH, Shell Deutschland GmbH, Vattenfall Vindkraft AB, WindMW GmbH and the scientific partners DanTysk Sandbank Offshore Wind GmbH & Co. KG, Northland Deutsche Bucht GmbH, Ocean Breeze Energy GmbH & Co. KG, OWP Butendiek GmbH & Co. KG, UMBO GmbH and Veja Mate Offshore Project GmbH.