Book 19, Question 63
Why Do Salmon Swim Up Rivers?
Many salmon hatch in a river, swim out to the ocean to grow, and then return to the river where they were born! They go home to lay their eggs. Then the next generation begins.
More fun facts
- Pacific salmon are famous for swimming from the ocean back to the river where they hatched.
- They return to that river to spawn, which means laying and fertilizing eggs.
- Before young salmon swim out to sea, they learn the special smells of their home stream.
- Learning these smells is called imprinting.
- Years later, adult salmon use their memory of those smells to find their way home.
- Salmon that never get to smell their home water at the right age are more likely to stray to other streams.
Sources: NOAA
Questions kids ask
Does the ocean changing affect salmon's sense of smell?
NOAA scientists are studying whether more carbon dioxide in the water, which makes the ocean more acidic, affects how salmon smell.