New report on effects of offshore windfarms on marine life

Professor Lena Kautsky from Stockholm University is one of the authors behind the new report, which concludes that consideration needs to be taken to sensitive benthic areas, sound sensitive animals, as well as seabirds when wind farms are established. It also concludes that the turbine foundations can act as artificial reefs.

Offshore windfarms. Photo: Nicholas Doherty /Unsplash.

The report from the Swedish Environmental Protection Agency provides a synthesis of current research about potential impacts of offshore wind farms on marine wildlife. The authors of the report recommend that follow­-up studies will be carried out in connection with the construction and operation of new offshore wind farms.

Shallow coastal areas are sensitive to disruption

When the windfarms are built, impulsive noise associated with pile driving, and sediment dispersal connected with activities to prepare the seabed for the turbines and cables, may harm the local biodiversity, marine mammals and fish.

Harour porpoise. Photo: Erik Christensen /Wikimedia Commons.

Measures to reduce impacts of impulsive noise are of critical importance. But the one most important measure is to wholly avoid sensitive areas when constructing windfarms.

The harbour porpoise is dependent on ecolocation for foraging and navigation and therefore particularly
sensitive to noise. The high noises during the construction phase need to be mitigated and special consideration for the porpoise needs to be taken when locations of the windfarms are planned.

Consideration also needs to be taken for sensitive or rare natural benthic habitats, where species can be harmed or killed during the construction, as well as risks to sea birds. Depending on the species of birds and their behaviour, they may risk either collision, or to be driven away from suitable mating or foraging areas.

Windfarms make up artificial reefs

Blue mussels and barnacles. Photo: Niall Benvie /Nature Picture Library /Universal Images Group Rights Managed /For Education Use Only.

The hard structures of the turbine foundations and their scour protection act as artificial reefs which attract both sessile and mobile species.

The windfarms can be built with structures that promotes biodiversity – layers of stones and boulders, holes to live or hide in.

Sessile filter feeding animals on the windfarms may also improve the local water quality.

Reed the report here (in Swedish with an English summary)

Text: Jenny Rosen