They have evolved to become such powerful swimmers that they are capable of jumping 10 feet out of the water to clear waterfalls on the way upstream to their spawning grounds.
However, the pressures on this extraordinary animal are now so great that there are fears they could become endangered in the Atlantic within a lifetime.
In just 25 years, the number of salmon returning from the sea to rivers to breed has fallen by 70 per cent. As the Atlantic Salmon Trust says, this is a “catastrophic decline”.
Now researchers are fitting tracking devices to young fish to find out where they go after they leave Scotland’s rivers and head to the ocean in the hope this will shed new light on what is going so badly wrong. Previous studies into the salmon’s early life in rivers found that 50 per cent of smolts do not make it to the sea.
Sudden changes in one species can have a knock-on effect on many others. For example, freshwater pearl mussels spend their early lives hitching a ride on the gill of a salmon or trout to reach suitable new habitat. As this taxi service becomes rarer, the mussels, already an endangered species, will be in even bigger trouble.
There are a number of theories why salmon numbers have fallen so sharply in recent years, but what we need are the facts.
Hopefully this latest research will uncover the salmon’s secret life at sea and help find a way to ensure that the long story of the ‘king of fish’ does not end anytime soon.