After hatching in a freshwater stream, young salmon make a break for the ocean, where they hang out for years, covering thousands of miles before deciding its time to settle down and lay eggs in their natal stream. So how do these fish find their way back to their home river? According to one theory, it’s all about magnetism.
Do salmon return to the ocean?
Then, in one of the animal kingdom’s more extreme migrations, the salmon return from the saltwater ocean back to a freshwater river to spawn afresh. After several years wandering huge distances in the ocean, most surviving salmon return to the same natal rivers where they were spawned.
This of course begs the inquiry “Why do young salmon return to the same stream years later?”
Let us find out. one hypothesis states that salmon retain an imprint of the odor of their natal stream as they are migrating downstream. Using this memory of the odor, they are able to return to the same stream years later. Another smell-related hypothesis states that the young salmon release a pheromone as they migrate downstream,.
You might be thinking “Do salmon go back to the river to spawn?”
Our answer is that When they have matured, they return to the rivers to spawn. There are populations of some salmon species that spend their entire life in freshwater. Usually they return with uncanny precision to the natal river where they were born, and even to the very spawning ground of their birth.
Why do salmon navigate their way home?
A random river might not have suitable sites for spawning, but a salmon’s birthplace is already a proven success for spawning. It may not have mates of the same species. Or conditions might not favor that type of salmon. For all these reasons, we can see why salmon navigate their way home .
According to one theory, it’s all about magnetism. When salmon are young, the theory goes, they imprint on the pattern of the Earth’s magnetic field at the mouth of their native river. Years later, when the salmon head back home to spawn, they home in on that pattern.
Where do salmon go after they die?
After several years wandering huge distances in the ocean, most surviving salmon return to the same natal rivers where they were spawned. Then most of them swim up the rivers until they reach the very spawning ground that was their original birthplace .
How long do salmon live at sea?
Chum may spend up to seven years at sea, but typically four. Pink salmon, on the other hand, spend a fixed 18 months at sea. Sockeye typically spend two years at sea, coho spend about 18 months, and chinook can spend up to 8 years before journeying back to their natal streams to spawn.