Watercourse

Wild salmon spend their first years in a river. The environment varies greatly both within the same watercourse and between different watercourses. The water temperature can vary from 0 degrees in winter to more than 20 degrees in summer. The water velocity varies from still water in lakes to roaring waterfalls and rapids in rivers. The water depth varies from shallow water near land to many meters deep. The bottom conditions vary from mud and fine sand to large boulders and solid rock. The oxygen content in the water varies greatly throughout the year and between different parts of the watercourse, but is rarely so low that the wild salmon suffocate.

The young salmon are found in shallow water along the shores of large rivers, in the shoreline of lakes or in small streams. The most important thing is that they find places to hide from fish-eating animals, and that they can find food themselves. They have camouflage that makes it difficult for enemies to detect them.

Tough competition

The competition between the young salmon for good hiding places and food is fierce. The young salmon that are best adapted to the conditions in the watercourse get the best places. They are the ones that grow the fastest and have the least chance of being eaten themselves.

Insect larvae are the most important food for the young salmon. In fresh water they are small and do not provide enough energy for the young salmon to grow large. In the ocean there is plenty of food, and there is no competition between wild salmon. If the young salmon are to grow large, they must therefore go to the sea. When they are the length of a ballpoint pen, they leave the river to migrate to the sea and grow large.

The adult salmon returns to its feeding river after one to five years to give life to new generations. It spawns in running water with enough oxygen for the large eggs. The females dig spawning pits in places where the size of the stones in the gravel is large enough.

We have done a lot of damage to wild salmon.

We have destroyed wild salmon in many watercourses, including through hydroelectric development, physical interventions, pollution, the introduction of diseases, alien parasites and fish species, and escaped farmed salmon. The Storting has given wild salmon special protection in 52 watercourses. We call these national salmon watercourses.

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