A new study which was published this week has found that offshore wind farms can actually be beneficial rather than detrimental to the local ecology. This is good news, particularly, due to the fact that offshore wind is expected to play a large part in the UK Government’s drive for renewable energy generation.
The study, entitled ‘Short-term ecological effects of an offshore wind farm in the Dutch coastal zone; a compilation’ observed the effect that the Windpark Egmond aan Zee (which is the first large-scale offshore wind farm to be built off the coast of the Dutch North Sea) had on the local ecology over the course of it’s construction and for the first two years in which it was operational. The full report was published in the journal Environmental Research Letters and can be found here. The wind farm was described in the report as being “the Dutch demonstration project, for gaining knowledge and experience for future large scale wind farms at sea.” It was carried out by the Institute for Marine Resources and Ecosystem Studies at Wageningen University and Research Centre and studied the impact the wind farm had on a number of species.
Firstly, porpoise populations were observed by studying the noise levels produced by their echolocation: “Echolocation activity was similar during the baseline period, but increased significantly more during the operation period. Free-swimming porpoises in the wild have been shown to vocalise almost constantly meaning that the chosen measurements of acoustic activity can be used as an indicator of the number of porpoises present. The results showed that relatively more porpoises are found in the wind farm area compared to the two reference areas. It was established that this effect is genuinely linked to the presence of the wind farm. The most likely explanations are increased food availability due to the attached fauna on and in the hard substrates (reef effect) as well as the exclusion of fisheries and reduced vessel traffic in the wind farm (shelter effect).” Other research has supported these findings; “Danish research studies indicate that operational wind farms are frequently visited by harbour porpoises and most likely used for foraging”.
Of course the increased presence of porpoises has to be supported i.e. there must inevitably be an increase in other forms of marine life in and around the wind farm. Some fish species did see an observable increase in their population and the wind farm did not appear to interfere with or damage their life cycle: “noise and vibrations from the turbine generators and electromagnetic fields from cabling do not seem to have a major impact upon fish and other mobile organisms”. Rather, quite the opposite was discovered; “observations indicate a possible refuge function of the farm for certain fish species”. Indeed; “some cod stayed near a single wind turbine for the whole nine-month measuring period.” From this research it can be seen that wind farms can be beneficial to some fish species, sheltering them from predators and providing them with habitat areas that have far less intensive fishing been carried out. This is of great benefit to species such as the, citied, Atlantic Cod which has seen populations collapse as a result of overly intensive fishing practises.
Other marine lifeforms such as mussels have also found wind farms to be a most supportive habitat; “species on the monopiles were observed in clearly observed in two distinguishable zones: an upper zone dominated by mussels and a lower zone dominated by tubeworms and anemones. Mussel larvae attach easily to the monopiles and grow very fast in this area. This feature might be used in the future to stimulate multiple use in the form of aqua culture in the windfarms.”
Finally, the effect of the wind farm on several species of bird was studied. The effects of wind turbines on bird populations is an issue which has been perhaps been exaggerated to the public, perhaps even more so with onshore wind turbines. Many of the public seem concerned with the issue of birds simply flying obliviously into the turbine blades. This was an issue that was not encountered during this study: “small groups heading towards the farm always reacted strongly when noticing the farm and changed course to avoid the farm. Northern gannets and possibly little gulls seem to avoid the wind farm”. Even migrating birds flying at turbine blade height (a frequently citied issue for some when talking about turbines) managed to naturally react to and avoid the turbine blades. For other species the wind farm was actually highly beneficial: “One seabird species, the great cormorant (Phalacrocrax carbo) was attracted to the wind farm and uses the site as a new platform for offshore foraging. These cormorants are birds from two colonies nearby… They commute between the colonies and the wind farm. They feed in and around the wind farm and use the monpiles and meteomasts for drying their feathers, resting, and socialising. The wind farm is thus an offshore outpost of the two colonies on the mainland.”
The report, then, suggests that the Windpark Egmond aan Zee quicly saw the development of a diverse ecosystem around it, providing a new habitat for a number of species. This is the conclusion that Professor Han Lindeboom from Wageningen University arrives at: “At most, a few bird species will avoid such a wind farm. It turns out that a wind farm also provides a new natural habitat for organisms living on the seabed such as mussels, anemones and crabs, thereby contributing toincreased biodiversity.
“For fish and marine mammals, it provides an oasis of calm in a relatively busy coastal area.”
We can hope that the findings of this report will be suitably promoted by the UK and Scottish Governments as it outlines the benefits of offshore wind farms and helps to dispel some of the myths about wind turbines in general.