The innovative, custom-built floating reef provides a sheltered habitat where European oysters can grow and thrive while showcasing the potential of large oyster reefs at sea. It currently supports around 10,000 juvenile European oysters, known as spat, settled on scallop shells, alongside approximately 200 adult oysters growing inside biodegradable bags.

Native oyster reefs were once a common feature of Northern Ireland's coastline but have declined dramatically due to overharvesting, habitat loss, disease and pollution. As natural ecosystem engineers, European oysters play a vital role in improving water quality, increasing biodiversity and creating habitat for a wide range of marine species.

The floating reef builds on the local nature conservation charity’s existing native oyster nursery at Glenarm Marina and pioneering work to restore native oysters in Northern Ireland. Earlier this year, the charity completed its first deployment of native oysters onto the seabed in Belfast Lough, marking an important milestone in the return of this once-abundant species. 

The new floating reef at Glenarm Marina recreates the habitat of a natural oyster reef above the seabed and could provide a new way to scale up native European oyster restoration in Northern Ireland. Early results are encouraging, with oyster survival rates exceeding 80%.

To better understand how wildlife is benefiting from the new habitat, an Eco-Detect camera system, powered by machine learning (a form of AI), has been installed alongside the floating reef. The technology records the mobile species visiting and interacting with the structure around the clock, providing valuable new insights into how oyster reef habitats support marine life.

During its first three months of operation, the system has recorded more than 7,000 wildlife detections, including fish such as gobies and seabirds including black guillemots. The findings are helping Ulster Wildlife build a more complete picture of the biodiversity value of oyster reefs, complementing existing research from its nurseries on less mobile species such as sea slugs, worms and other invertebrates.

Dr Nick Baker Horne, Marine Conservation Manager at Ulster Wildlife, who has led the initiative, said: "The floating oyster reef represents an exciting new chapter in our work to restore the native European oyster to Northern Ireland’s seas and revive a habitat that has been lost for generations. It allows us to showcase the incredible habitat created by native oysters while continuing to build our oyster restoration efforts and deepen our understanding of the wildlife these reefs can support. Thanks to Eco-Detect’s camera system, we can now see what species are interacting with this floating reef, day and night.

“Oyster reefs are true ecosystem engineers – they help improve water quality, support richer marine biodiversity and create healthier coastal ecosystems. Clearer waters and thriving marine life can benefit local fisheries, while living reefs also store carbon and help protect coastlines from storm surges. Restoring these vital habitats is essential if we want to build healthier, more resilient seas for the future."

The project also has wider ambitions for marine habitat restoration. Ulster Wildlife plans to develop methods for collecting naturally washed-up seagrass on the floating reef before growing and replanting it to strengthen the local seagrass meadow in Glenarm. This will provide a welcome boost to this vital and fragile underwater habitat.

The floating oyster reef has been developed by Ulster Wildlife in partnership with Mid and East Antrim Borough Council and is funded by the Department of Agriculture, Environment and Rural Affairs (DAERA) via the Carrier Bag Levy. The project forms part of a wider programme to restore native oysters and other blue carbon habitats around Northern Ireland.

Find out more about Ulster Wildlife's work to bring back the native European oyster