How millions of oysters could be reintroduced to Scotland's waters

Scientists in northern Scotland hope newly introduced oyster habitats will help to get the local ecosystem thriving once again, as ITV News Louise Scott reporter explains

Scotland is famed for its clear waters and stunning landscape, and that’s no different on the Dornoch Firth, the most northerly estuary in the UK.

As dawn breaks, a group of scientists and marine biologists head out across the calm waters to a protected area.

They form part of the Dornoch Environmental Enhancement Project (DEEP), a collaboration between Heriot-Watt University, The Glenmorangie Distillery and the Marine Conservation Society, who are aiming to reintroduce four million oysters by 2030.

They’ve so far added 60,000 and the first of its kind study has found that biodiversity in the Dornoch Firth waters will be doubled within a decade.

Lead author Naomi Kennon from Heriot-Watt University told ITV News: "Oysters are quite often called an ecosystem engineer, so what that means is they form the ground level.

"If you think about it all the way to the top of the ecosystem you’ve got the predators like the seals and dolphins, so they will be benefitting from more fish, the fish will be benefitting from more crustaceans.

"This means the population of species will increase in a balanced way. Our data has also shown a link between increased shell material as the oyster population grows and increased biodiversity."

Naomi Kennon (right) explained to ITV News how the reintroduction of oysters will benefit much of the local ecosystem. Credit: ITV News

Populations of the European native oyster have dropped 85% worldwide over the past century.

In the Dornoch Firth, oysters covered the seabed for more than 8,000 years, but they became locally extinct in the 19th Century due to overfishing.

Researchers are taking oysters, which have been harvested from Loch Ryan, in Scotland’s west coast, to reintroduce to the highland estuary.

The oysters are dropped into the water close the surface, before sinking down to the seabed

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Ms Kennon said: "They’ll slowly sink down to the bottom, when they get there and they are happy they’ll open up; start breathing, taking in the water and then they’ll start filter feeding."

Over time the oysters will improve water clarity and even help mitigate the effects of organic waste from the local distillery.

The divers brought to the boat oysters, which had been dropped in over a-year-ago, to show us exactly how the ecosystems will grow.

"You can really really see the difference here. It’s got massive barnacle growth, it’s pretty incredible really," Ms Kennon added.

Project lead Professor Bill Sanderson added: "You can see all of the structure building up and this is in March time, in the middle of the summer there will be loads more."

Professor Sanderson said the study has been imperative to the ongoing oyster project, explaining: "These findings are significant for DEEP and for the Dornoch Firth.

"But more broadly this research will help to inform the many marine conservation projects around the world that have taken inspiration from this exemplary project."

The reintroduction of oysters will improve the waters of the Dornoch Firth over the coming decades, but the research will have an even wider impact by encouraging the restoration of oyster reefs around the world.

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