Abstract
Two marine ornithologists spent two days watching seabird behaviour from a fixed platform at the periphery of offshore wind farm Luchterduinen, The Netherlands, in January 2018. The aim of this study was to assess whether meaningful observations could be made from a non-moving platform, that was part of the wind farm scenery, i.e., one of the turbine foundations. On each observation day, a turbine was selected that was located at the wind farm perimeter, that offered views both of the interior of the wind farm and to waters just outside the wind farm. Earlier studies of seabirds in offshore wind farms have shown that many species tend to avoid wind farms, but also that some individuals, of most species, do enter. However, as these studies are typically conducted from moving platforms (ships or aircraft), it is not known how birds behave within a wind farm perimeter. Birds that find themselves between moving turbines might be intimidated. This might impair their normal feeding behaviour at sea, if the birds would be overly watchful, or mainly seeking to exit the wind farm. On the other hand, birds may specifically move into a wind farm, if they can deal with the fact that turbines are present, and if feeding conditions within the wind farm are good. Such birds would be expected to show feeding behaviour, such as diving.
Seabirds may also be habituating to the presence of wind farms in their environment. In the airspace below the rotors, at the sea’s surface and under water, there is no danger to seabirds from collision. Seabirds can thus safely enter and feed in offshore wind farms, and may, over the years, have learnt to exploit this new habitat. Therefore, even though earlier studies have shown displacement of seabirds away from offshore wind farms, this may no longer be the status quo as seabirds may be adapting to the new situation: a marine environment with offshore wind farms.
Two auk species, the common guillemot and the razorbill, were seen to move through the wind farm. Birds were seen here both flying and swimming, and diving (presumably for food) was commonly seen. Northern gannets were also commonly seen within wind farm perimeters, but only flying: not swimming or diving. We observed bird behaviour during only two days, in a relatively new wind farm not visited by us earlier, while using different methods of observing seabirds, as compared to earlier T-0 and T-1 studies nearby offshore wind farms. Acknowledging these methodological limitations, seabird presence in the wind farm seemed considerably higher than observed during the earlier T-0 and T-1 (personal observations) periods. This might suggest that these birds (both auks and gannets) are habituating to the wind farms in their environment.
Based on this pilot study of only two days of observations in only one season, it is fair to conclude that meaningful behavioural observations can be made from the turbine foundations and that the suggested process of habituation can be followed. It is suggested to conduct more such observations and to do so both from peripheral turbines and from turbines deeper into the wind farm.