why do some salmon get lost? how common is it?

Question

I have seen salmon trying to run up waterfalls, up canals etc. Why do they get lost? How common is it for the salmon to get lost/confused about which way is really upstream?

thanks

Answer 1

It is getting more common for Salmon to get lost. Some believe it due pollutants changing the scent of a river and that to some extent the fish use scent to find the way back home.

Answer 2

Very common, but what your seeing is not them getting lost. If you ever watch salmon migrate up stream to spawn, they jump out of the water and swirl at the surface. They are just fighting the current and attempting to gain momentum. And they do get lost some times... People think salmon will go back to the exact stream to spawn. This isn't 100% true. They often return the the right river system but not the correct stream.

Answer 3

Salmon don't get lost. They are returning to the place from whence they were spawned. Running up stream and leaping waterfalls, locks, and dams is what they do. In some areas engineers build in what are called fish ladders to enable them to pass such obstructions.
As far as hormones are concerned, that is waaay off. It is instinct, not hormonal.

Answer 4

What makes you think they're lost because they scale waterfall, dams and the like ? They go to their birth place to spawn -- to my knowledge, they only way the get lost is by being lunch for some creature.

Answer 5

maybe something is wrong with their hormones. Salmon by nature have hormones like we have hormones which acts as a body clock that directs them from where they came from.

Situation like this is rare. Its minimal.

Answer 6

They're males and refuse to ask for directions.