The first signs of a bumper new generation of wild native oysters have been found in Loch Ryan.
This comes as the Stranraer Oyster Festival is set to take place this weekend.
The oysters were discovered following an unusually large spawning event in the loch this summer.
Young oysters have now settled on specially prepared collectors laid on the seabed in June, and the fishery that manages Scotland's last wild native oyster bed says the results of the first checks of the collectors, which took place earlier this week, are very positive.
The news comes as the Stranraer Oyster Festival opens on the shores of the loch on Friday, September 11, with Loch Ryan natives on the menu and the biggest line-up of celebrity chefs the community-run festival has ever hosted.
Loch Ryan is one of Europe's most important native oyster beds, with oysters from the loch supporting restoration projects around the UK as well as supplying some of the country's top restaurants.
The bed is managed on conservation principles, with around 95% of each catch returned to the loch to encourage the oyster bed to grow.
In June, when the fishery team were installing spat (baby oyster) collectors, they found that around 30% of the oysters they sampled were brooding larvae at the same time, their flesh turned a milky grey by the tiny larvae each one was carrying.
Loch Ryan's bed is home to an estimated 23 million native oysters, according to a stock assessment carried out by Professor Bill Sanderson of Heriot-Watt University for the Solway Coast and Marine Project.
A third of that population is roughly seven million oysters, and each native oyster carries around a million larvae.
Around June 10, when they released those larvae into the loch, it is estimated that trillions of baby oysters entered the water within a few days of each other.
Tristan Hugh-Jones, director of Loch Ryan Oyster Fishery Company, said: "A native oyster only carries its larvae for around three days before releasing them into the sea, so to find a third of the sample brooding at exactly the same moment leapt out at us.
"We have simply never seen this proportion of Loch Ryan oysters spawning simultaneously in such numbers before.
"When so many are breeding together, the larvae have far more opportunity to be fertilised and to settle, and that gives us real hope of a good spatfall."
Native oyster larvae swim freely for around ten days before settling on the seabed and fixing themselves to a hard surface, ideally shell.
Whether a spawning becomes the next generation of Loch Ryan native oysters depends entirely on where, and whether, the larvae settle.
Loch Ryan's geography is particularly well suited to native oysters, as the sheltered waters of the sea loch retain a large proportion of the larvae rather than letting them drift out to sea.
To find out where this year's larvae were landing, the fishery placed collectors at various locations around the loch.
The collectors included coupelles, stacked plastic plates used by oyster farmers, and concrete blocks coated in lime and laid directly on the seabed.
The lime coating creates the closest thing to an artificial shell surface for larvae to attach to.
It also makes the young oysters far easier to see and count.
The collectors were checked earlier this week, and it was found the blocks on the seabed did the best job, with hundreds of young oysters settled on the lime-coated surfaces.
Tristan believes the marine heatwave reported around the UK earlier this year is the likely driver of the early spawning.
He said: "Native oysters need to settle on a firm, shelly surface, and the lime gives them exactly that.
"Taken together with what we saw in June, the bed this summer looks to be in the healthiest state it has been for a very long time."
The Stranraer Oyster Festival runs from Friday, September 11 to Sunday, September 13 on Stranraer's waterfront, from 5.30pm until late, Saturday 10.30am until late, and Sunday 10.30am to 6.30pm.
Day tickets are £8–£12, weekend tickets £26–£32, and a free festival shuttle bus runs throughout.
Children attend free of charge.
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