How do salmon have multiple spawning locations if they return to where they hatched?

Question

Wouldn’t they only have one starting location? Or do they just sometimes get their directions wrong?

In: 12

Answer 1

Returning to the spawn is just a preference. Their instinct is to swim upstream to find a nice place to lay their eggs regardless of if this is their spawn site or not. There are various things which can bring them off course. The river might be blocked for example. Or it might be overcrowded with too many salmons. The salmon can also get turned around and swim up the wrong way.