Offshore Wind Ecological Programme (Wozep)

The Wozep research programme was launched in 2016 to explore the knowledge gaps relating to the ecological effects of offshore wind energy. This research programme was commissioned by the Ministry of Economic Affairs and Climate (EZK) and it will include research into the assumptions made in the Framework for Assessing Ecological and Cumulative Effects (KEC).

WOZEP logo


Before 2016, the construction and operation of the wind farms in the Dutch North Sea was preceded and accompanied by monitoring and research. The individual operators conducted a monitoring and evaluation programme for each wind farm in order to study the effects on the ecology and nature of the North Sea. On the basis of the knowledge generated by these research programmes, an initial model estimate has been made of the net effect of all existing and planned wind farms in the North Sea in the period leading up to 2023 on explicitly protected bird and marine mammal species listed in the European Birds and Habitats Directive. This Framework for Assessing Ecological and Cumulative Effects (KEC) was developed by Rijkswaterstaat in collaboration with scientific partners for the Ministry of Agriculture, Nature and Food Quality.

However, the use of model estimates that are insufficiently validated due to gaps in our knowledge leads to uncertainties in the predictability of the ecologically 'safe' construction of all these new offshore wind farms. Further research is therefore indispensable. Now, with the construction of ten wind farms planned in a short period of time, it has been decided to look for an approach that is better adapted to research into the effects (including the cumulative effects) of offshore wind energy on the ecosystem and into the underlying mechanisms. In a change with the past, the government is now directly managing these follow-up studies. The aim of this policy change is to make research more efficient and obtain more relevant information that can be applied more directly. EZK therefore commissioned Rijkswaterstaat to develop and implement a new monitoring and research programme during the period 2016-2021. The new knowledge about the effects (including the cumulative effects) of offshore wind farms will be used immediately, for instance to reduce uncertainties in the KEC results.

Activities in 2016

In the start-up year of 2016, Wozep set up a number of preparatory activities in the context of the specified themes. This mainly involved feasibility studies, possibilities for model-based approaches, the preparation of measurement systems, and surveys of existing knowledge and data. In this process we also take into account of what has been and is being done in the North Sea countries that surround us.

Monitoring and research programme 2016-2023

In late 2016, a long-term monitoring and research programme was completed that sketched out the research lines for the period 2017-2021 (Wozep was extended to 2023 in 2018). The client, experts and stakeholders were involved in working out and selecting the research lines, with the latter being determined on the basis of a comparative assessment using two time horizons:

  • Short term (period leading up to 2023): the aim is to use the results in the planned wind farms. The emphasis here is on studying the assumptions made during the ecological assessment of these wind farms. In addition, the research will also cover the usefulness, necessity and efficacy of the measures imposed on the wind sector to limit ecological damage.
  • Long term (after 2023): what do we need to know in order to ensure that the ongoing construction of offshore wind farms is ecologically sound, what are the expected effects of the further expansion of the number of wind farms on the North Sea, where exactly can they be positioned and with which possible consequences, how can negative effects be adequately avoided? And so on.

An assessment will be made every year during the entire research period to see whether, in the light of the results, the approach needs to be adjusted and which additional projects are required in order to study the principal knowledge gaps. Coordination with other North Sea countries is one of the main priorities.

During the eight-year period covered by Wozep, there will be a great deal of groundbreaking work. Furthermore, a huge amount of new knowledge about marine ecology and how it is affected will be generated. Once again, we are faced with the challenge of using this new knowledge effectively in order to meet our energy needs in a sustainable way.

Wozep a five-year research programme

What will Wozep examine?

The main knowledge gaps relate to the effects - particularly cumulative - of the construction and operation of offshore wind farms on the habitats (protected and otherwise) of marine mammals (porpoises and two species of seals), marine and coastal birds, migratory land birds, underwater habitats (for benthic fauna and fish) and, surprisingly, bats that migrate across the North Sea. Harbour porpoises and common and grey seals probably suffer most disruption as a result of the noise caused by pile-driving during the construction of a wind farm. The noise may make the affected area unsuitable as a resting and foraging area for these species for a longer period of time, affecting their fitness and therefore their chances of survival and reproduction. Seabirds and coastal birds can be negatively affected by operational wind farms in two or three different ways. Species may tend to avoid artificial offshore structures because they do not recognise them as a 'habitat'. They are then forced to move to alternative areas. This costs extra energy and/or time and it has a detrimental effect on fitness. Species that are not frightened away by wind farms run the risk of colliding with the rotating rotor blades of the turbines. This can cause higher mortality, which can in turn lead to unacceptable effects on the population. Migratory land birds and bats that migrate across the sea also run the risk of colliding with the turbines. It is only very recently that direct observations at night using bat detectors and ringing campaigns have shown that Nathusius’s pipistrelles in particular migrate back and forth between the European mainland and the United Kingdom on a regular basis. In addition, as they fly over land, bats are demonstrably attracted to wind farms and they indeed fall victim to collisions on a regular basis and it is entirely clear that this species, which is strictly protected under European law, also merits attention. Wozep also covers possible changes in the underwater ecosystem. Changes in currents and/or patterns of erosion and sedimentation, whether or not associated with the presence of hard substrate on the seabed, can theoretically cause changes in underwater habitats and have knock on effects on primary production and possibly on fish, birds and marine mammals. There is still a lot of insecurity on this subject .