Vattenfall

North Sea nature is under pressure. To learn how we can enrich this nature, The Rich North Sea is researching nature reinforcement in the North Sea. We look at the marine life in various offshore wind farms. For this we work together with various partners, including Vattenfall. Vattenfall is currently building the Hollandse Kust Zuid Wind Farm. The Rich North Sea and Vattenfall are jointly investigating the possibilities for improving native biodiversity. Previous research shows that wind farms increase local biodiversity and contribute to adequate fish stocks. Is there an opportunity to increase this effect?

What are we going to do?
In this project we investigate the effect of water replenishment holes in the hollow foundations of the wind turbines. These holes ensure that the water in the foundation flows well and is refreshed. But through these holes, fish and other organisms also have access to the foundation. The hollow cylinder of about 8 by 25 meters can serve as a shelter and feeding place for various forms of marine life such as fish, anemones, crabs and shrimps. These water replenishment holes have been installed in all 140 foundations of the wind turbines of the Hollandse Kust Zuid Wind Farm.

Vattenfall and The Rich North Sea, together with the Royal Netherlands Institute for Sea Research (NIOZ) and Wageningen University (WU), are looking at the living conditions inside and outside the foundations. We investigate whether the living conditions, such as oxygen content and temperature, are suitable for the development of marine life in the foundation. Furthermore we investigate difference between the conditions inside and outside the foundations. We are also curious how marine live will develop over time in this environment.

For this research we are testing innovative monitoring techniques, which we may be able to use in the Hollandse Kust Zuid Wind Farm and other wind farms in the future.

What are we going to learn?
The first part of the project will be completed in early 2022. During a number of offshore expeditions, measurements were carried out with special equipment. The data from these measurements gives us a good first impression of the water conditions, such as flow rate, turbidity and nutrients.. This information is important, because they determine the living conditions of different species. In addition, images and DNA analyses provides insights into the first species that settle inside and outside the foundations.

In the future, we can monitor the water conditions and marine live around the foundations. With this research we gain knowledge about the role of water replenishment holes in foundations of offshore wind turbines on marine life. How can these be optimally desgined to help biodiversity? The aim is to be able to apply this knowledge later on in the construction of future offshore wind farms.