The Danish Energy Authority, Danish Forest and Nature Agency, Dong Energy and Vattenfall have released "Danish Offshore Wind - Key Environmental Issues," an eight-year study on the impacts of two offshore wind farms, Horns Rev and Nysted, on the aquatic ecosystem including birds, fish, seals and benthic life. Horns Rev and Nysted are the owners of the two wind farms that were studied.
The study shows that waterbird species tend to avoid wind farms by changing their flight direction a number of kilometers away to deflect their path around the site. Birds flying through a wind farm tend to alter altitude to avoid the risk of collision. The report also shows that fish populations at the wind farms appear to be similar to what they were before the construction of the wind farms. It suggests that some fish avoid the area while others seem to be attracted to it - depending on its species.