Nature Champions: European Flat Oyster Beds

European flat oysters (also known as native oysters, scientific name Ostrea edulis) live in shallow coastal waters or estuaries up to around 30 metres deep, but have also been known to survive in waters up to 80 metres deep. Most oysters live between five and ten years, but can live up to 30 years in rare cases.

They require shells, stones and other hard surfaces for their larvae to settle on, and are important ‘ecosystem engineers’.

In the right conditions, native oysters can form beds in their thousands, filtering millions of litres of seawater and providing a vitally important nursery and feeding habitat for juvenile fish and shellfish.

Due to historic overfishing, pollution and siltation there has been a decline of oyster populations in Scotland by over 95% since the 19^th century. But this has been part of a global decline, with global populations declining by 85%.

The Firth of Forth once contained an oyster bed the size of Edinburgh, from which as many as 30 million oysters a year were harvested at the peak of the fishery. Today, the wild fishery in Loch Ryan is the last of its kind in Scotland. A number of MPAs, such as Loch Sween, have been designated to protect native oyster populations.

Photo: © David George / Marine Conservation Society