A North-Sea wind farm contributes to increased biodiversity and has hardly any negative effects on fauna, according to a Dutch research report.
For two years a research team studied benthic organisms (life at the sea bed), fish, birds and marine mammals at the OWEZ offshore wind farm near Egmond aan Zee.
Their study shows that the wind farm hosts a new natural habitat for organisms living on the sea bed such as mussels, anemones, and crabs. For fish and marine mammals, it provides an oasis of calm in a relatively busy coastal area. The main negative aspect is that a few bird species avoid the wind farm.
Local biodiversity increased since new species of benthic organisms establish themselves in the sandy areas between the wind turbines, and communities of animals arise on the wind turbine piles and the rocks piled around the columns.
The fish fauna turns out to be very variable. The wind farm seems to provide shelter to cod. Porpoises were also heard more often inside the wind farm than outside it.
Various bird species, including the gannet, avoid the wind farm, whereas others, such as seagulls, do not seem to be bothered by the wind turbines. Cormorants were even observed in greater numbers.
The number of birds that collided with the turbines was not determined but was estimated to be quite low on the basis of observations and model calculations.
On the basis of comparisons with results found elsewhere, the scientists conclude that the impact of a wind farm depends on the location of the wind farm and the depth of the surrounding sea. The location of the OWEZ wind farm is favourable due to the relatively low numbers of birds that fly through the area at this distance from the coast.
Intensive fishing, pollution, gas oil and sand extraction, and intensive shipping have already resulted in changes to the ecosystem. In such an environment, a wind farm can contribute to a more diverse habitat and even help nature to recover. In the busy Dutch coastal zone, the wind farm seems to offer a relative oasis of calm, according to the researchers.
The research was carried out by a consortium consisting of the IMARES marine ecology research institute, the Royal Dutch Institute for Maritime Research (NIOZ), and Bureau Waardenburg. It was funded by NoordzeeWind, a joint venture of Nuon and Shell Wind Energy.
“This environmental study was carried out in accordance with the Government preconditions and is non-biased. Although I am not surprised by its general conclusions, we have learnt a lot from it,” says Henk Kouwenhoven, Senior Development Manager, Vattenfall BD Renewables. Kouwenhoven devoted over 10 years of his professional career to the OWEZ offshore wind farm, which was built 2005-2006 and commissioned 1 January 2007. The wind farm consists of 36 V90 turbines, 3 MW each, totalling 108 MW.
The link to the project web site is www.noordzeewind.nl
Environmental Research Letters online