A project to return native oysters to the UK in a bid to improve the health of coastal waters will start growing thousands of the shellfish beneath harbour pontoons.
Ecologists consider oysters to be “ocean superheroes” for their ability to filter sediment, nitrates and other pollutants from the seas.
Nitrate-based fertilisers can end up in the sea as a result of run-off from farmland or sewage spills, causing algal blooms that deprive the water of vital oxygen.
A mature oyster can filter up to 200 litres of water a day, but native oysters are on the brink of extinction, with numbers declining 95% since the 1800s.
Around 4,000 mature oysters will be installed in six harbours across the North East of England, Wales and Scotland as part of the Wild Oyster Project.