How do fish know where they are going in the ocean?

Question

I’ve been looking up about Orcas, and I realized, how the hell do fish know where they are going in the middle of the ocean when there are no physical markers? It’s just water in every direction and depths so deep you cant see the bottom. I need google maps and I’ll still get lost. Is it something about magnets?

In: Biology

Answer 1

For salmon, scientists think that they use smell to return to the river they came from. Essential to this are the ones that make a mistake and return to the wrong river. This ensures biodiversity in the gene pool.