On an unseasonably hot May day in Aberdeenshire, Edwin Third stands by the River Muick, a tributary of the UK’s highest river, the Dee, explaining the growing threats to one of Scotland’s most iconic species — the Atlantic salmon. Behind him, across the moorland of the Cairngorms National Park, a herd of stags reclines in the sunshine.

It’s a stunning landscape, popular with walkers, mountain bikers, and salmon anglers — the latter contributing an estimated £15m to Aberdeenshire’s economy.

But according to Third — river operations manager for the Dee District Salmon Fishery Board and River Dee Trust — climate change is jeopardising the survival of spring salmon in the Dee’s Special Area of Conservation, a river where King Charles once learned to fly-fish.

Rising temperatures in the upper tributaries, where spring salmon are born, along with altered flow patterns caused by increasing winter floods, are contributing to what Third describes as a “massive decline” in their population.

Spring salmon are famed for their endurance, migrating thousands of kilometres to west Greenland and back, navigating waterfalls to return to their natal streams to spawn.

“We have over 300km of streams classified as vulnerable to warming water temperatures,” says Third, holding up what he describes as a “scary map” of such rivers drawn up by the Scottish government. “We’ve had 27.5C in some. Salmon feel stress at anything over 23C.”

Third, who was born and raised in Deeside and has worked on the river for 30 years, recalls winters when chunks of ice would break off and drift downstream. But over the past three decades, water temperatures in the Dee have risen by 1.5°C.

As illustrated by yellow patches on climate vulnerability maps, many of the river’s upper tributaries are now categorised as highly susceptible to warming — a serious concern for the Dee, one of Scotland’s “big four” salmon rivers, known for its high-quality fishing. While many rivers across the country are suffering steep declines, the Dee has thus far fared better. In Scotland, 72% of rivers (153 rivers in total) are currently classified as having “poor” conservation status for salmon; the Dee is among just 15% (31 rivers) rated “good”.

However, data from the Scottish Government’s longest-running wild salmon monitoring programme — based at the Girnock Burn, a key tributary near the Muick — has caused concern among conservationists, anglers, and estate owners. In 2024, just a single, solitary female salmon returned to spawn — the lowest number since records began, and a sharp decline from the 200 in 1966. Another tributary, the Baddock Burn, recorded only seven returning females — its fourth lowest count on record.

According to the Missing Salmon Alliance, a coalition of conservation and angling organisations, these figures represent a “catastrophic decline” in the Dee’s spring salmon population.

Coupled with other alarming indicators — including a 96% fall in spring salmon rod catches, from 8,000 in the 1950s to fewer than 500 today — a 20-year initiative called Save the Spring is attempting to reverse the trend.

The first five years of the project comprise a £5 million partnership between the Dee District Salmon Fishery Board, the River Dee Trust, the Atlantic Salmon Trust, the University of Stirling, and UHI Inverness. The programme has two primary components: habitat restoration and improvement, and a controversial pilot intervention called “conservation translocation”. This method — inspired by a project in Canada’s Bay of Fundy and has been used by the Royal Zoological Society of Scotland to reintroduce wildcats to the Cairngorms — aims to address the most perilous stage in a salmon’s life: its time at sea.

Currently, only three out of every hundred salmon return from the sea to spawn, says Third. By intervening during this phase, the hope is to increase survival rates.

Last year, around 100 young salmon, or smolts, were captured and transported 200 miles (320 km) to a larger seawater tank on Scotland’s west coast. Once mature — later this summer — they will be returned to the river.

However, the bulk of the work centres on habitat restoration, particularly tree planting for shade, and river re-engineering to moderate flow rates.

“The extremes of flows are one of the pressures on salmon,” says Lorraine Hawkins, river director of the Dee District Salmon Fishery Board and Trust. “They can wash juveniles and eggs out of the river.”

Placing deadwood in streams, for instance, changes the current and creates favourable spawning environments and safe zones for salmon eggs to survive.

Drier summers are placing salmon under increased pressure, with some stranded in dried-out riverbeds. Hawkins, a conservationist involved in the project, reports receiving calls from the public to rescue trapped fish.

Without riparian woodland, floods and droughts become more extreme, and river temperatures rise more quickly. Yet in the River Muick, wild salmon populations — though still critically low — have shown early signs of recovery after ten years of restoration work, according to Save the Spring.

Third gestures across the moorland, dotted with bog cotton and a scattering of alder, birch, and Scots pine saplings planted by his team. The upper Dee has just 8% tree cover, he notes, compared with a European average of 37%.

“The river would have had woodland in the past,” he says. “There are so many deer here, the trees don’t get peace to grow.”

High deer populations — maintained for trophy stalking on the surrounding private estates — make tree regeneration difficult. Balmoral and the Glenmuick Estate are among those supporting the Save the Spring project.

The initiative is not without its critics. A  paper published last year questioned the scientific basis for salmon restoration projects such as this, arguing that because marine mortality is the dominant cause of salmon loss, river-based interventions may have limited effect. Concerns have also been raised about the risk of introducing diseases from externally reared fish into otherwise pristine river systems.

A Save the Spring spokesperson responded that the project is addressing “critically low wild salmon populations” facing extinction.

“They do not have the luxury of another 30 years of academic study – they are a species on the brink.”

It is guided by best practice set out by the International Union for the Conservation of Nature (IUCN), and informed by senior scientists with expertise in Atlantic salmon conservation, landscape ecology, peatland restoration, government policy, and water resource management.

A University of Stirling spokesperson added that the relocated salmon are “closely monitored” and undergo thorough health checks prior to release.

So far, 150,000 trees have been planted along the Muick, including within a fenced 40-hectare site on the Balmoral Estate. Once mature, these trees are expected to reduce water temperatures by several degrees, says Third.

The ultimate goal is to plant 1 million new native trees by 2035 — including rowan, aspen, Scots pine, birch, willow, and hawthorn. Across Scotland, fishery boards are pursuing similar planting efforts to help cool river temperatures and create suitable conditions for salmon recovery.

 

 

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