Battle to save world’s leading salmon river from pink invaders

A BATTLE is under way to save the world’s most famous salmon river from an invasion of potentially harmful aliens.

Emergency measures have been put in place to try to prevent the River Dee – internationally renowned among anglers – from being colonised by Pacific humpback salmon.

The Scottish Government is worried about ‘unprecedented’ numbers of the non-native pink salmon being found in Scotland’s rivers and threatening the country’s native Atlantic salmon.

Record numbers of the humpbacks have appeared in Scottish rivers this year – and experts have confirmed for the first time they are breeding.

Now The Scottish Mail on Sunday can reveal that, on the Dee in Aberdeenshire, urgent action is being taken to thwart the alien menace.

Conservation staff have stretched nets across the river to capture and destroy the humpbacks.

They have also waded into the water to dig up the humpbacks’ nests and remove thousands of their eggs.

Anglers have been ordered to kill any humpbacks they catch rather than return them to the river.

It is feared the invaders could compete for food and territory as well as spread diseases to native salmon.

The scale of the invasion was revealed by the Scottish Government in a recent parliamentary answer. Roseanna Cunningham, Cabinet Secretary for Environment, Climate Change and Land Reform, said: ‘In recent weeks, anglers in at least 18 Scottish rivers and netting stations in the River Esk and Tweed have reported historically unprecedented numbers of fresh run non-native pink salmon.

‘As at the end of August, Fisheries Management Scotland (FMS) have recorded that approximately 140 have been caught in Scotland.’

She said work was continuing to investigate ‘the potential impact this could have on Scotland’s wild salmon populations’, including laboratory tests on eggs to assess the likelihood of successful spawning.

Pacific pink salmon were introduced to some Russian rivers in the 1960s and have slowly spread westwards to colonise some northern Norwegian rivers. They have previously been recorded in Scotland in small numbers – but never on the scale of this year.

On the Dee, sweep netting – where workers in dry-suits encircled the salmon with a 240ft net – captured 24 adult humpbacks.

Meanwhile nests, or redds, in a number of rivers across Scotland have been destroyed using spades, picks and hoes, with loosened eggs caught in a net.

Dee Fishery Board director Mark Bilsby admitted he was ‘worried’ by the unprecedented numbers.

He said: ‘Our Atlantic salmon have enough threats going on in their lives at the moment. We’re not seeing the abundance that we once did, and another threat is the last thing we need. There has been a UK-wide rapid risk assessment done and that says, where possible, kill and remove this species.

‘Until we’re told these animals are not going to pose a risk to Atlantic salmon, any pink salmon caught will be killed and removed.’

Dr Alan Wells, FMS chief executive, said: ‘We have seen unprecedented numbers of pink salmon in Scottish rivers in 2017, a situation that appears to be mirrored across the North-East Atlantic.

‘The UK Non-native Species Secretariat have produced a risk assessment and this... concludes that pink salmon are “very likely” to establish in the UK.’

‘Enough threats in their lives at the moment’