The Interesting Life Cycle of Salmon

Delicious, easy to prepare, and healthy, salmon may well be one of nature’s gifts to us human beings. Pan fry, bake, or grill it – it usually doesn’t disappoint.

Okay, salmon feed us, but before they end up on our plates, they rather live an interesting life. With a lifespan of two to seven years (for most species of salmon, at least), they usually travel great distances over their lifetime. Basically, they are born in freshwater, migrate downwards to the sea, and go back to the freshwater where they were born (or hatched – but for the sake of style, let’s use born) to spawn, and well, die. Taking on a long journey to the place you were born so you can die there – what’s more poetic than that?

Of course, between birth and death, life happens. So, what’s living like for salmon?

The newly-hatched salmon are called alevins, where the yolk sac of the egg are attached to their bellies. For a few months, they stay close to the redd (rocky nest). When they have absorbed the yolk sac and grown in size, they “swim-up” the gravel of the riverbed. It can be said that this is where their journey begins – they swim freely and are exposed to dangerous to predators for the first time. And, along with this milestone are the bragging rights of being called fry.

Fry can spend up to a year or more in their home stream, where they feed on microscopic invertebrates. Then there comes the call of the ocean (really, one can’t ignore that). So, they migrate seawards. This is also the time when smolting begins, where their scales grow as their turn a silvery colour.

Salmon spend one to seven years in the ocean. Then they take their long journey home. To locate their home stream, they use a combination of magnetic orientation, celestial orientation, the memory of their home stream’s distinct smell, and a circadian calendar.

Salmon go home to breed, but what comes with it is their death. They stop feeding as soon as they reach freshwater. They don’t die in vain, though. Besides making way for a new generation of salmon, their journey home also means that they are bringing with them millions of tons of nutrients to their home stream, benefiting all levels of the food chain, from bacteria to bears. This is because they accumulate marine nutrients and store them in their body as they grow in the ocean environment. When they die, these nutrients are released.

Of course, we are also one of the beneficiaries of salmon’s meaningful existence. It is one of the healthiest fish to eat – it is an excellent source of protein and an array of vitamins and minerals. It’s also rich in omega-3 fatty acids, which are known to be good for the heart.

All in all, it won’t be so much of a stretch if we say that salmon’s short time on Earth is something we can strive for (metaphorically, mostly).