More than 15 million juvenile oysters are set to be released into the North Sea as part of one of the largest rewilding projects in UK waters. The initiative aims to re-establish a vast oyster bed near Orkney, which experts believe will trigger a 'trophic cascade' of climate and ecological benefits.
Richard Land, the marine expert leading the project, said the scheme would have a knock-on impact on the entire ecosystem. 'It won't just benefit fish and the bay, it will benefit sea mammals, seabirds and the whole environment,' he said. The project, backed by the Green Britain Foundation, the Nature Restoration Fund, Marine Fund Scotland and North Bay Innovations, is intended as a blueprint for reviving oyster beds around the UK and European coasts.
Oyster beds were once a key part of UK marine ecosystems, covering vast coastal areas, with some North Sea beds spanning the size of Wales. However, overfishing during the Industrial Revolution, when Londoners alone consumed an estimated 700 million oysters between 1840 and 1850, combined with pollution, climate change and channel clearance, devastated populations. Scientists say this caused a 'negative cascade' that decimated marine ecosystems.
The project also offers climate benefits. Dale Vince, founder of the Green Britain Foundation, noted that oyster reefs can sequester significant amounts of CO2. The new bed, covering over 100 hectares, could sequester up to 76 tonnes of CO2 annually, with the potential for that figure to increase a thousand-fold after 15 years if natural spawning occurs. 'Restoring native oyster beds is a perfect example of how we can work to restore nature and fight the climate crisis at the same time,' Vince said.
The Orkney initiative uses a unique rearing process, cultivating juvenile oysters onshore on calcium carbonate-enriched plates. These plates are then placed in the sea on long lines to protect the oysters from predators until they are large enough to form beds, creating reefs that support scallops, molluscs, algae, seaweeds and invertebrates.
Local MP Alistair Carmichael welcomed the plan, saying, 'Efforts to restore and recover historic wildlife in the isles are absolutely welcome, particularly if there is an opportunity for carbon sequestration at the same time.' Dr Philine Zu Ermgassen of the University of Edinburgh added that such reintroduction schemes are critical because oysters are now too few in number to recover naturally in many locations.
