Once salmon near and enter fresh water, scientists think they use their sense of smell to find not only their home stream or river but the specific tributary or area of the river where they were born. Juvenile salmon imprint on the unique chemical signatures of the waters where they were born and occupied as fry as well as on the waters they migrated through to get to the ocean.
How do salmon find their way back to the river?
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.
How do salmon find their way back to the ocean?
Pacific salmon are known to imprint on the chemical signature of their home river. This information helps salmon find their home river once they reach the coast from the open sea. In most cases, chemical cues from rivers are not thought to extend very far out into the ocean.
Then, how do salmon migrate?
Salmon can migrate out to sea to feed for several years before returning to spawn in the same stream, sometimes even the same section of stream, in which they were born. Other homing species probably use similar mechanisms, but few can match such precision.
You should be thinking “Why do salmon cross the ocean?”
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.
Why do young salmon return to the same stream years later?
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,.
Before they end up filleted and sautéed on your dinner plate, salmon lead some pretty extraordinary, globe-trotting lives. 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.