Underwater habitat and fish

The most significant impacts of offshore wind power on the underwater habitat take place in the construction phase. Impacts during operation are usually low, especially if there are other operations nearby, such as a port or a shipping channel.

Underwater foundations create an artificial reef for fauna and flora. This may improve the living conditions of some species and living cycles. According to a study carried out in the area of an offshore wind farm in Denmark, especially mussels attach themselves onto the foundations of the wind farm, and the amount of fish and other fauna and flora increased.

The above-mentioned reef impact may create a new habitat for some fish species. On the other hand, during the construction stage, spawning areas can be destroyed either temporarily or permanently. The construction of an offshore wind farm is scheduled so that the impacts on fish spawn will remain as small as possible.

In offshore wind power projects, the zoobenthos is adversely affected by the installation of undersea cables, but the situation is normalised rapidly after the installation stage, and corresponding zoobenthos quickly grows in the area again. The magnetic field caused by the cable is estimated to be larger than the natural geomagnetic field only at the distance of up to one metre from the cable at the most. Therefore, the magnetic field of the cable probably does not have significant harmful impacts on the fauna. [1]

Sources:

SEAS Distribution A.m.b.A., 2000. Havmøllepark ved Rødsand.Vurdering af Virkninger på Miljøet – VVM-redegørelse.July 2000.