Their prize is the king of fish, but anglers intent on catching wild Atlantic salmon are now being urged to form a land army to help save it.

Rising numbers of non-native pink salmon – thought to have originated from Russia - outbreaks of a range of mysterious diseases and escaped farmed fish are said to be combining to push already dwindling stocks of native wild Atlantic salmon to crisis point.

Now with the new salmon season underway, Scotland’s angling community is being called upon to take up arms and help track a triple threat to the iconic species, in the hope of helping pull it back from the brink.

Anglers and the general public are being asked to become ‘guardians’ of their local rivers, and report sightings of diseased, non-native and escaped farmed fish via a new suite of three apps.

Launched by Fisheries Management Scotland, a key member of the Missing Salmon Alliance, the apps have been developed so reports of sightings can be fed straight to a central database to be assessed and shared with relevant organisations.

In the case of fish disease reports, the Scottish Government’s Fish Health Inspectorate would be notified – helping to speed up responses and for action to be taken.

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Incidents of fish being found with a range of distressing diseases including fungal infections, ulcerative dermal necrosis and red skin disease, have increased in recent years. In the case of red skin disease, fish develop a rash, with bleeding and ulceration on the underbelly and near their mouth which is eventually fatal.

While some are naturally occurring, increased incidences of unusual skin conditions in salmon – which often only become evident when fish are either caught by anglers and appear dead in the water - have perplexed fish health experts.

It’s also hoped that the apps will help build up a picture of the scale of the intrusion of pink salmon in Scottish waters – expected to soar this year as the species enters a key breeding year.

A Pacific salmon species with distinctive humpback and curved mouth, pink salmon were originally introduced to some Russian rivers in the 1960s when their release was regarded as a positive initiative.

However, they spread slowly westwards to colonise some northern Norwegian rivers. In 2017, unprecedented numbers were captured across Scotland and elsewhere in the UK along with Norway, Finland, Iceland, Denmark and Germany, rising concerns that their presence will put pressure on native salmon food, spawning grounds and fish health.

The apps will also help track escaped farmed fish, which are bred to thrive in a farm environment and are not adapted to surviving in the wild. Once in open water, they raise the risk of genetic impacts should they breed with wild salmon and trout.

It’s hoped the ‘citizen science’ mobilisation will help authorities fully understand the extent and severity of the triple threat at rivers across Scotland at a time when native wild Atlantic salmon numbers are already under pressure from climate change, pollution, predation by fish, birds and seals, and non-native plants that erode riverbanks.

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Launching the apps, Fisheries Management Scotland also called on everyone who values local rivers and Scotland’s iconic wild salmon to join a national call to action aimed at speeding up delivery of critically-important conservation measures.

It urges the Scottish Government to take decisive action to restore wild salmon by taking a raft or urgent measures, including the immediate delivery of crucial commitments in its Scottish Wild Salmon Strategy. Launched last January, the strategy sets out a range of measures aimed at boosting the species including improving river habitats.

The organisation has also called for the introduction of “effective regulation of the fish farming industry” which protects wild salmon and sea trout, and tougher penalties for those who cause environmental damage.

It also wants to see a review of hydro-electricity to ensure all life stages of wild salmon have free-access to habitat and sufficient water to access it Around 90% of all wild Atlantic salmon in the UK are foun d in Scottish rivers. However, their survival rate is low, with studies suggesting just five out of every 100 that leave rivers bound for the ocean never come back.

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Numbers of wild salmon returning to Scotland have declined by around 40% in the past four decades, with fears that the species may be placed on the endangered list in less than ten years and potentially vanish entirely.

Dr Alan Wells, Chief Executive of Missing Salmon Alliance member, Fisheries Management Scotland, said: “Fisheries managers across Scotland are working hard to protect and restore our precious wild salmon and freshwater fish, but we cannot do this alone.

“We need the help of anglers, fishery owners, other water users and the general public to use our apps to report issues affecting our wild fish.

“This will play an important part in informing the actions that fisheries managers and Scottish Government agencies take to address these pressures.”