Offshore Wind Ecological Programme (Wozep)

In 2016, a five-year research programme was launched to study the knowledge gaps in the ecological effects of offshore wind energy. This research programme will be managed by the Central Government and amongst other things will study the assumptions that were made in the Ecology and Cumulation Framework (KEC). We call this research programme the ‘The Dutch governmental offshore wind ecological programme’, and its Dutch abbreviation is Wozep (‘Windenergie op zee ecologisch programma’).

WOZEP logo


The construction and operation of the wind farms on the Dutch North Sea were preceded and accompanied by monitoring and research. For each individual wind farm, a monitoring and evaluation programme was implemented to examine the effects on the ecology and nature of the North Sea. The initiator of the permit was responsible for the research. The knowledge gathered from these research programmes for existing wind farms was used to create an initial model estimate of the net effect of all existing and planned wind farms on the North Sea up to 2023 on explicitly protected bird and marine mammal species in the Bird and Habitat Directive (EU). This Ecology and Cumulation Framework (KEC) was commissioned by the Ministry of Economic Affairs and developed by Rijkswaterstaat in cooperation with scientific partners.
However, the use of insufficiently validated model estimates due to a lack of knowledge has resulted in uncertainties about the predictability of being able to build all those offshore wind farms in an ecologically ‘safe’ way. Further research is therefore urgently necessary. Now that 10 wind farms must be realised in a short time, the search has begun for an approach that is better suited to research the (cumulative) effects of offshore wind energy on the ecosystem and the mechanism behind it. In contrast to the past, the Government is now directly managing these follow-up studies. The aim of this policy change is to conduct more efficient research and obtain more relevant information that can be applied more directly. The Ministry of Economic Affairs has therefore commissioned Rijkswaterstaat to develop and implement a new monitoring and research programme during the period 2016-2021. The new knowledge about the (cumulative) effects of offshore wind farms will be used immediately, for instance to reduce uncertainties in the KEC results. We have called this new programme the ‘Dutch governmental offshore wind ecological programme’, which has the Dutch abbreviation Wozep.

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 2017-2021

In late 2016, a long-term monitoring and research programme was completed in which the research lines for the period 2017-2021 were outlined. The client, experts and stakeholders were involved in working out and selecting the research lines. The research lines were selected by making a comparative assessment based on two time horizons:

  • Short term (up to 2023): aimed at using the results in the planned wind farms. Here, the emphasis is on the study of the assumptions made during the ecological assessment of these wind farms. In addition, the study also examines the usefulness, necessity and effectiveness of the measures imposed on the wind sector in order to limit ecological damage.
  • Long term (after 2023): which knowledge is necessary to ensure that further expansion of offshore wind farms takes place in a responsible way, 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, etc.
During the five-year period of Wozep, a great deal of ground-breaking work will be done and a huge amount of new knowledge about marine ecology and how it is affected will be gathered and developed. Yet again we are facing the challenge of using this new knowledge effectively in order to make the energy need sustainable.
Wozep a five-year research programme

What will Wozep examine?

The main knowledge gaps are in the area of the (cumulative) effects of the construction and use of offshore wind farms on the protected habitats and groups of species (and habitats) of marine mammals (porpoises and two species of seals), marine and coastal birds, migratory land birds, underwater habitats (for seabed fauna and fish) and, surprisingly, bats that migrate across the North Sea.
Porpoises and common and grey seals probably experience the most disruption from the noise caused by from pile-driving when a wind farm is being constructed. Because of this, the area can be unsuitable as a resting and foraging area for these species for a longer time, and this can affect their fitness and therefore their chances of survival and reproduction.
Marine and coastal birds can experience disruption from operational wind farms in two or three different ways. Species may be inclined to avoid artificial offshore structures because they do not recognise them as their ‘habitat’. They then deem it necessary to relocate to alternative areas. This costs extra energy and/or time and has a detrimental effect on their fitness. Species that are not deterred by wind farms run the risk of colliding with the rotating rotor blades of the turbines. This can cause higher mortality rates, which in turn can lead to unacceptable effects on the population.
The risk of collisions also applies to migratory ‘land birds’ and migratory bats (across the sea). It is only very recently that direct observations at night using bat detectors and ringing recoveries have shown that particularly Nathusius’ pipistrelle structurally migrates back and forth between the European mainland and the United Kingdom. And when we add that as they fly over land bats are demonstrably attracted to wind farms and that they are indeed regular victims of collisions, it becomes clear that this species group that is strictly protected under European law also deserves attention.
Wozep also focuses on the possible changes in the underwater environment. Changes in currents and/or patterns of erosion and sedimentation, whether or not in the presence of hard substrate on the seabed, can theoretically lead to possible changes in underwater habitats. These changes can affect the availability of food and therefore the quality of the habitat for protected species. This applies both to a number of fish species and to marine mammals and birds.