ULTFARMS follows the UNITED project, which aimed to combine offshore wind development with aquaculture, focusing on flat oysters and seaweed as proper feed is required when enhancing aquaculture in OWFs. A key focus was the restoration of oyster reefs, which once covered a quarter of Belgium’s North Sea but are now almost extinct. Given the hard substrates provided by OWFs, UNITED explored the feasibility of using these structures to reestablish oyster reefs. The project investigated whether adult oysters could be introduced to these environments to settle, reproduce, and contribute to aquaculture by catching larvae in water column.

ULTFARMS started in 2024 to further UNITED’s mission. The ULTFARMS project involves adding structures with adult oysters to the sea, and using spat collectors with clay settlement plates, which are favored by oysters. Clear substrates are placed on scour protection around turbines, and these structures are monitored to observe the growth of various species, including anemones and mussels. The project employs divers for monitoring, requiring favorable conditions and coordination with offshore wind farm (OWF) operators to ensure safety during diving missions. Monitoring also involves eDNA techniques to track shellfish diseases.

• Start small and test what’s working before running expensive tests. The ULTFARMS project required Bonamia-tested oysters, which are expensive. Test with small numbers to ensure that oysters can survive the placement process, then purchase larger amounts only after successful tests.
• Test as much as possible near shore or in controlled environments so that the expenditures on ship time, insurance, and days at sea are used as efficiently as possible based on preliminary data.
• Good communication with your OWF operator is crucial. They will provide information about placement and dedicated locations for structures.
• It is beneficial to use registered vessels with experience in OWFs, and to have good communication with the crew and captain.
• Network throughout your process! ULTFARMS initially opted for baskets for oysters, but the team learned that the stress of movement in baskets may impact oyster reproduction. To have adult oysters that can reproduce, a different and more stable design (like tripods) is preferrable.
• Working with divers is not always allowed due to risk and exposure. In Belgium this is allowed for scientific research but the project enabled the development of acoustic releases to retrieve structures without divers or ROVs.
• Include monitoring in your project plan from the start and reserve a budget for it.
• Monitor for as long as possible. Many projects only last 2-3 years, but longer term (10-20 years) would be ideal, even if not always feasible.
• Turn your decommissioning into a last monitoring activity. Before removing everything right away, use this opportunity to learn.
• Decommissioning is often overlooked and not accounted for, but it is a critical step. Don’t miss this in your planning!

As UNITED and ULTFARMS were research projects, environmental permits, assessments, and impact reports were not needed for this particular process. An agreement from the wind farm operator was required, as well as insurance. Near-shore tests in protected areas also need evaluation for environmental safety and approval by authorities.