The Arduous Migration of the Salmon

The salmon that reaches our tables has travelled a very, very long way. And this doesn’t just mean the distance from the fish plant onto our plate!

Many fish reproduce where they themselves hatched. During this mass migration, some of the most conspicuous fish are the salmonidae – the salmon.

The Life of the Salmon

In general, young salmons grow up very slowly. They remain in freshwater for two to five years before the move to the sea. There, they continue to grow, and that happens even faster than in freshwater.

It is unbelievable how much strength a salmon, which may have travelled already up to 1000 km in the sea, can summon when it wants to return to its spawning-ground. All the way UP the course of the river that it once swam DOWN. The highest spawning-grounds are at an altitude of 700 m!

A Migration With Many Obstacles

Often it takes several attempts before a salmon manages to overcome an obstacle like a rock, for example. During that process, it often becomes injured as well. But many of the fish's wounds also originate from fights between males, which is an additional drain on their strength during the arduous journey. Among the females, the digging and covering of the spawning hole saps their strength. For that reason, mortality after spawning is very high. In addition, these fish, like we humans, can become ill with arteriosclerotic vascular changes.

It is assumed that only 4 - 6% of salmon spawn a second time, and only 1% a third time.

The Atlantic Salmon And Its Multiple Strategies

The Atlantic salmon occurs in many forms, which may show different migration behaviour.

Some even stay completely in freshwater and only migrate between two lakes. There are even totally settled species.

One genus of Pacific salmon in America (Oncorhynchus) seems to never survive spawning.

The quinnat salmon spawns in the Yukon Territory no less than 3000 km away from the ocean.

For the Atlantic salmon there are impressive numbers as well: Animals marked in Sweden were caught on the west coast of Greenland 4800 km away!