Giving the fish a fighting chance How trees could save salmon in River Dee

On an unusually hot May day in Aberdeenshire, Edwin Third stands on the bank of the River Muick, a tributary of the UK's highest river, the Dee, talking about the rising threats to one of Scotland's most celebrated species, the Atlantic salmon.

- Karen McVeigh

On an unusually hot May day in Aberdeenshire, Edwin Third stands on the bank of the River Muick, a tributary of the UK's highest river, the Dee, talking about the rising threats to one of Scotland's most celebrated species, the Atlantic salmon. Against the hills of the Cairngorms national park, a herd of stags bask in the sun.

It is a spectacular landscape, attracting hikers, mountain-bikers and salmon fishers, the latter contributing an estimated £15m to Aberdeenshire's economy. But according to Third, the river operations manager for the Dee District Salmon Fishery Board and River Dee Trust, the changing climate threatens the survival of spring salmon in the Dee's special area of conservation, a place where King Charles learned to fly-fish.

Temperature rises on the upper tributaries, the birthplace of the spring salmon, and altered flow patterns caused by increasing winter floods, are both linked to a "massive decline" in the spring salmon population, Third said. Spring salmon migrate thousands of miles to west Greenland and back, leaping up waterfalls, to return to their natal streams to spawn.

"We have over 300km of streams classified as vulnerable to warming water temperatures," said 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 in Deeside, has worked on the river for three decades. He recalls a time when chunks of ice would break off and be swept downstream. But temperatures in the Dee have increased by 1.5C over 30 years. Many of its upper tributaries are now classified as highly vulnerable to rising temperatures.