A study commissioned by the Federal Association of Wind Farm Operators Offshore eV (BWO) for a network of funding partners shows that the progressive expansion of wind power at sea has no negative impact on the population of loons in the German Bight. The possible effects of offshore wind farms on the population and the habitat of the two species of loons, red-throated and black-throated divers were examined. The most important result: The loons population and thus also the importance of the main concentration area in spring for these birds has remained stable after the expansion of wind energy that has taken place so far.

The study "Divers (Gavia spp.) in the German North Sea: Changes in Abundance and Effects of Offshore Wind Farms ”was created by BioConsult SH, IBL Environmental Planning and the Institute for Applied Ecosystem Research (IfAÖ) on behalf of the BWO for eleven companies from the offshore wind industry. In particular, the evaluation of stock data for the years 2001 to 2018 and, for the first time, the recording of winter stocks (in addition to the important spring stocks) are new. The monitoring data of all offshore wind farms currently in operation are also taken into account. All operators of offshore wind farms are obliged by the Federal Maritime and Hydrographic Agency (BSH) to monitor the marine environment over a period of several years in the large area around the respective wind farms. The study is thus based on the largest data set currently available on the distribution and occurrence of red-throated and black-throated divers in the German North Sea. The aim of the study was to analyze the development of the loons population against the background of the increasing expansion of offshore wind power.

Stefan Thimm, managing director of the BWO: “The study shows that climate protection and species protection do not contradict each other. This was also shown by the Gescha-2 study, which found no measurable effects of offshore pile driving on the harbor porpoise occurrence in the German North Sea. The operators of offshore wind farms will continue to work to further reduce possible disruptions through innovations in construction and operation. "

The recently published study shows that loons maintain different avoidance distances to the wind farms, depending on regional and seasonal aspects and that the spring population of loons in the German North Sea was stable overall over the study period from 2001 to 2018 (average over the years approx. 16.500 birds) . Nevertheless, there are fluctuations between the years, but these can be explained by possible influences such as weather and food availability. A causal relationship between the annual fluctuations in the number of loons and the expansion of wind power could not be established. The scientists have also shown that the loons population is stable despite spatial shifts in the main concentration area northwest of Sylt and that the area continues to be of great importance for resting loons in spring. There is no apparent evidence that the area has reached its carrying capacity.

About the client

The study was carried out on behalf of the BWO for EnBW Energie Baden-Württemberg AG, RWE Renewables International GmbH (formerly: E.ON Climate & Renewables GmbH), innogy SE, Merkur Offshore GmbH, Orsted Wind Power A / S, OWP Butendiek GmbH, OWP Nordergrund GmbH, PNE AG, Trianel Windkraftwerk Borkum GmbH & Co. KG, Vattenfall Europe Windkraft GmbH and WindMW GmbH.