Abstract
The Belgian pilot of the ULTFARMS project explores the integration of aquaculture within offshore wind farms, building on earlier insights from the UNITED project. Conducted in the Belgian North Sea, the pilot combines seaweed cultivation, flat oyster farming, and nature-inclusive design approaches for oysters in a highly exposed offshore environment, aiming to develop scalable and resilient multi-use systems.
Despite significant environmental, technical, and logistical challenges, the pilot achieved key advancements in offshore aquaculture design and operation. Experimental work highlighted limitations in replicating offshore conditions, which were addressed through wave flume testing and scaled prototype validation. The development and deployment of submersible longline systems in a commercial field site demonstrated enhanced storm resilience, with successful submersion strategies informing buoyancy control and material durability. Field operations were frequently constrained by weather and vessel availability, necessitating adaptive approaches such as the reuse of existing datasets and flexible deployment strategies.
Technical challenges in artificial oyster reef deployment emphasized the need for robust designs and innovative installation methods, including acoustic retrieval systems to overcome restrictions on scientific diving. Offshore cultivation trials further confirmed that early-stage deployment and seeding techniques are critical for success, while losses of cultivation units underscored the importance of material selection and structural optimization.
Financial and logistical constraints, including high insurance costs and limited offshore access, reinforced the importance of strong cross-partner collaboration and resource sharing. Mitigation strategies implemented throughout the project resulted in improved system resilience, refined design methodologies, and actionable insights for industry, academia, offshore wind operators, and policy stakeholders.
Key recommendations include the integration of contingency planning for extreme weather, dedicated budgeting for offshore risks, and prioritization of nearshore test systems as stepping stones toward full offshore deployment. Overall, the Belgian pilot demonstrates that while offshore multi-use aquaculture remains challenging, adaptive design, iterative testing, and collaborative approaches can significantly enhance feasibility and scalability.
Acknowledgment
This work was developed under the ULTFARMS project, financed by the European Union's Horizon Europe Research and Innovation Program under Grant Agreement no. 101093888. The authors would like to thank all members of the ULTFARMS Belgian Pilot for their contributions to the discussion and work that informed the development of this work.