Offshore wind farms can affect animals that live in the sea or migrate over the sea. There may be negative effects such as disturbance and mortality. And there can sometimes be positive effects (new habitats due to the introduction of hard substrate) for some species. Ecology is an important issue in the appraisal of the different interests involved in the construction of offshore wind farms. The roll-out of offshore wind farms must comply with the ecological parameters set out in the Nature Conservation Act.
Uncertainties persist about how wind farms affect the North Sea ecosystem. Research is therefore being conducted to obtain answers to important questions about construction and operations. European regulations require a safe margin as a precaution when there is a lot of uncertainty about the relationship between an intervention and the effects. Uncertainty about ecological effects is also a factor in the cost-efficient implementation of the objectives for offshore wind energy. In order to better understand how both the construction and operation of wind farms affect the ecology, the government has commissioned a range of studies:
In addition to the government-funded research programmes, the operators of the Egmond (OWEZ), Princess Amalia (PAWP), Luchterduinen and Gemini farms have a research programme that is mandatory under the conditions of the permit (which includes a monitoring and evaluation programme obligation).
Accumulation of ecological effects
Ecological knowledge is important to establish a picture of the accumulation of ecological effects. An assessment framework has been produced (the 'Framework for Assessing Ecological and Cumulative Effects' or KEC) that focuses less on the effect of individual wind farms and more on the ecological impact of all the wind farms as a whole. The Framework for Assessing Ecological and Cumulative effects (KEC) looked at the cumulative ecological effects of the wind farms that are in place, under construction or planned for the future in the period leading up to 2030. The aim of the KEC is to determine whether all the built and planned wind farms, when viewed as a whole, will have 'significant negative effects' on the ecology.
It focuses on the effects on harbour porpoises, some species of seabirds and migratory birds and on Nathusius's pipistrelle. These are the species and groups of species that are expected to be affected most and that are protected under nature conservation legislation. Where necessary, requirements will have to be included in the site decisions to prevent or reduce the effects. In the 2016-2021 North Sea Policy Document, the national government committed itself to drawing up and applying a Framework for Assessing Ecological and Cumulative Effects.
The KEC is an instrument that was developed in the Netherlands and is now used here. There is also an international focus on a common approach for identifying the ecological effects of offshore wind farms. The Political Declaration made by North Sea energy ministers on energy cooperation between North Sea countries (June 2016) included agreements about the development of a common framework for reporting on environmental effects (CEAF = Common Environmental Assessment Framework).