Photo by Amy Gulick
Salmon are a true wonder of our remarkable ocean planet. The salmon life cycle is an intricate eight-stage marvel of growth and round-trip migration.
When salmon eggs hatch, tiny alevin emerge with yolk sacs attached. Alevin stay in their gravel steambed “redds,” or nests, because the weighty yolk sacs make movement difficult. The yolk sacs are their nutrient-rich lunch bags as the alevin absorb the yolk sac and transform into baby salmon, called “fry.”
Fry swim to the water’s surface, fill their swim bladders with oxygen, and begin to feed and grow. They eventually leave their natal streams and migrate to the ocean to feed and live in the salt water.
Finally the anadromous salmon later return to their freshwater birth streams to spawn and die. How salmon find their way back to their birth waters has been the subject of much research. Scientists believe they navigate magnetically, by sensing and responding to the Earth’s magnetic field.
In this exquisite way, salmon complete their circle of life in the place where it began.
* mahalo to the International League of Conservation Photographers (ILCP) for introducing us to this photo
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