This fish lives for part of its life in the high quality freshwater streams and rivers of Scotland and then spends most of its life at sea growing to adulthood in the Atlantic Ocean. It returns to the same freshwater tributary where it hatched, then it mates and spawns, laying its eggs in the gravel bottom. Most adults die after this epic journey, some females return to the sea and repeat the cycle the following year.
In spring, salmon fry (50-75mm long) can be seen in river shallows. Look out for their shadows on the stones of the riverbed. They grow over two or three years to be parr, looking like trout (100–200mm long) and can be seen in deeper pools. In spring and early summer in their second to fourth year, these parr change colour and become silvery and turn into saltwater tolerant smolts, as they journey down stream to the sea.
After years at sea feeding on plankton, sand eel and herring they return to freshwater rivers to breed. Adult salmon can be seen making spectacular jumps up waterfalls from May until September. They can be nearly a metre long and weigh up to 25kgs. Most salmon spawn in November-December.
Look for younger salmon in spring and summer by approaching the edge of shallow water quietly. Patient watching at any waterfall on a salmon river can be rewarded with glimpses of jumping adults. Watch spawning fish at a distance from the bank of the river and seek a viewpoint 2-3 metres above the river overlooking a gravel bed in around 100-150mm of water. Use binoculars to look for adults resting near these shallows.
The journey of an atlantic salmon is an epic one, involving hundreds of miles. Each female salmon can produce up to 750 eggs. Out of 5000 eggs laid about 4700 fry develop and at the end of their first year only 360 fry remain. During the following three years 260 parr dwindle to 50 or so smolts, which reach the sea. At the end of three more years at sea, 10 adult salmon might return to spawn again in the river and only one female may survive to return to the sea.