Van Oord, Ecowende to Install Tree Reefs and Oyster Hubs at Dutch Offshore Wind Farm

February 25, 2025, by Adnan Memija

Van Oord and Ecowende, a joint venture of Shell, Eneco, and Chubu, have signed a contract for the design, construction, and installation of Tree Reefs and Oyster Hubs at the Hollandse Kust West VI offshore wind farm in the Netherlands.

Developed by Van Oord Ocean Health, these methods aim to naturally enhance biodiversity in the North Sea.

The trees will be collected from the Dutch fruit cultivation sector and are usually cleared as soon as they start producing less fruit.

The Tree Reef concept was developed by the Royal Netherlands Institute for Sea Research (NIOZ). The institute’s pilot project in the Wadden Sea showed that the complex structure of fruit trees can offer marine life a highly valuable habitat, said the companies.

A large North Sea Tree Reef is expected to create habitats for even more benthic and fish species.

The company plans to install the Tree Reefs in 2026 on four cable crossings at the wind farm, with approximately 1,000 trees forming the reefs. They are expected to biodegrade underwater within 10 to 20 years, gradually being replaced by natural reef-building species.

In addition, Van Oord and Ecowende will collaborate on constructing Oyster Hubs at the 760 MW Hollandse Kust West VI offshore wind farm.

The hubs consist of adult oysters of varying sizes placed on designated cable crossings to serve as a source of oyster larvae. The wind farm will function as a connection site, stimulating larval distribution to otherwise isolated locations (e.g., oyster grounds) and facilitating the colonisation of new areas, according to the companies.

The Oyster Hubs will be installed in 2026 or 2027 on three cable crossings.

Van Oord has already installed Oyster Hubs at multiple offshore wind farms, including Borssele 1 and 2 and Luchterduinen.

Ørsted and Van Oord to Install Droppable Oyster Structures at Borssele 1&2 Offshore Wind Farm

R&D

The Hollandse Kust West VI offshore wind farm will be built approximately 53 kilometres off the coast of IJmuiden.

Van Oord will be responsible for transporting and installing the foundations; designing, procuring, and laying the connecting cables between the wind turbines; and transporting and installing the wind turbines.