Oyster reefs once thrived in the North Sea, providing essential ecosystem services such as water filtration, habitat creation and coastal protection. However, due to overfishing, habitat destruction and disease, native flat oyster populations have drastically declined, leaving the North Sea’s seabed largely barren. 

At the same time, offshore wind energy is expanding rapidly, creating opportunities to integrate biodiversity restoration into wind farm projects. Ørsted aims to enhance marine ecosystems within its offshore wind farms and sought scalable solutions to reintroduce native oyster reefs. The challenge was to develop structures that could support oyster larvae production while withstanding offshore conditions. 

As part of its biodiversity initiatives, Ørsted has deployed droppable oyster structures at Borssele 1 & 2 Offshore Wind Farm in the Dutch North Sea. These innovative reef structures are designed to provide a stable substrate for adult oysters, that function as larvae producers encouraging natural reef development. The structures are made from sustainable materials and are designed to be easily installed at scale. 

The project builds on Ørsted’s previous experience with biogenic reef restoration and involves collaboration with marine experts to monitor the reefs’ development. By placing these oyster structures within offshore wind farms, Ørsted not only contributes to marine biodiversity but also explores how wind farms can serve as relatively undisturbed areas that support broader ecosystem recovery. 

In partnership with the Ocean Health initiative of global marine contractor Van Oord, the oyster structures were successfully deployed in October 2024, to test an innovative installation method for scalable oyster reef restoration. If successful, oyster reefs could improve local biodiversity by providing shelter for marine species and enhancing water quality through natural filtration. 

Ørsted’s approach demonstrates how offshore wind farms can go beyond energy production to actively contribute to marine conservation. The findings from this pilot will inform future biodiversity initiatives, with the potential for large-scale implementation across Ørsted’s global offshore wind portfolio. 

With offshore wind expanding worldwide, projects like this highlight how renewable energy infrastructure can be designed to support both climate and biodiversity goals, ensuring a more sustainable future for marine ecosystems. 

Associated partners:

Ocean Health  

Van Oord 

Technical University Delft