Oyster reintroduction project in Scottish Highlands set to transform region’s biodiversity, say researchers | Climate News

The reintroduction of millions of previously extinct oysters to part of the Scottish Highlands is expected to turn the region into a bastion of biodiversity, researchers have said.

Native European oysters have almost disappeared in the UK, with the population declining by 95% since the mid-19th century, likely due to overfishing.

It has also led to the virtual disappearance of oyster reefs under the seas of the UK coastline.

But the Dornoch environmental improvement project, launched in 2014will reintroduce four million of them to a protected area in the Dornoch Firth on the banks of the Glenmorangie distillery by the end of the decade.

It is one of many oyster restoration projects in Europe that scientists hope will improve marine biodiversity and water quality.

To get an idea of ​​the project’s potential impact, researchers from Heriot-Watt University in Edinburgh studied the biodiversity of Scotland’s last native oyster fishery at Loch Ryan.

It has been in operation since 1701 and uses what is known as a rotational harvesting system – meaning different areas are fished each year, then restocked for six years before being fished again.

Biodiversity “expected to double in a decade”

Lead author Naomi Kennon said her university’s work suggested biodiversity where oyster restoration projects were underway “will likely double over a decade”.

“This means that the population of species will increase in a balanced way,” she added.

Ms Kennon’s colleagues have looked at the impact of oyster reef development and any biodiversity gains at Loch Ryan at different stages after oyster habitat fishing.

They researched wildlife biodiversity, oyster shell density, and oyster shell percentage.

The modeling was then used to predict changes in diversity over time.

Calum Duncan, Head of Conservation Scotland at the Marine Conservation Society, said: “The Loch Ryan study shows that increasing seabed complexity allows many species to find refuge in this living reef.”

The Marine Conservation Society is collaborating on the project with Heriot-Watt and whiskey maker Glenmorangie, which provided the funding.

It is hoped that 200,000 oysters will have been replenished by the end of next year.