Ørsted and Van Oord’s initiative, Ocean Health, have installed Droppable Oyster Structures (DOS) in the Borssele 1&2 offshore wind farm. These structures are easily portable reef systems with adult oysters attached. The oysters reproduce by producing larvae, which will colonise and eventually form oyster reefs within the wind farm.
The Droppable Oyster Structures can be installed by manually placing them on the seabed from the deck of a small vessel. An underwater camera will be used to monitor the structures and oysters over time to assess the method’s effectiveness and its impact on the local ecosystem.
Approximately 150 years ago, around 20% of the Dutch North Sea seabed was covered with large-scale oyster reefs. Today, wild oyster reefs have virtually disappeared, along with the valuable ecosystem services they provided. These services include filtration, which improves water quality, and the provision of habitats, food, and shelter to numerous fish and shellfish species, promoting biodiversity. Offshore wind farms provide hard substrate and undisturbed seabed, making them suitable locations for restoring the flat oyster population in the North Sea.
