Animal · Norway, Iceland, Ireland
Atlantic salmon
Salmo salar — the name this animal has in the language scientists everywhere share.
The Atlantic salmon hatches in a gravel bed in a river, swims out to the open sea, and years later comes back to the very same river. Finding that one stream again among thousands is one of the great journeys in the animal world.
Picture credit: Charles Cusson/Atlantic Salmon Federation (CC BY-SA 2.5) · Peter Steenstra at the Green Lake National Fish Hatchery (Public domain) · E. Peter Steenstra/USFWS (Public domain) · Wikimedia Commons
Where does the Atlantic salmon live?
Home: cold rivers and the open North Atlantic.
In the wild it lives in these countries: Norway, Iceland, Ireland, the United Kingdom, Canada, the United States, Russia, Greenland.
Conservation status from the IUCN: close to being at risk.
The short profile
Fully grown: 70 to 80 cm as an adult. It weighs about 4.5 kilograms. On the menu: meat.
The story behind it
A young salmon spends its first years in the river as a striped parr, hunting insects in the current. Then its body changes: it turns silver, its gills learn to cope with salt, and as a smolt it lets the water carry it down to the sea. Out in the North Atlantic it grows fast on capelin, herring and sand lance, and after one to three years most salmon weigh between three and five kilograms. For the way home it seems to use the earth's magnetic field over long distances and then the smell of its own river for the last stretch, and only about one salmon in twenty ends up in the wrong one. Upstream it pushes against the current, leaping waterfalls and weirs, and the male's flanks take on a red-brown wedding colour. The female digs a hollow in the gravel with her tail and lays thousands of eggs, which the male fertilises before the gravel is swept back over them. Unlike Pacific salmon, some Atlantic salmon survive spawning, drift back to sea thin and worn out, and may make the whole journey a second time.
Find it on the globe
Atlantic salmon is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
How big does an Atlantic salmon get?
After two years at sea a typical salmon is about 70 to 80 centimetres long and weighs three to five kilograms. Fish of over a metre exist, and the heaviest one ever reported weighed close to fifty kilograms.
Where do Atlantic salmon live?
The rivers where it breeds run from Portugal north to Norway, Iceland and Greenland, and along North America from New England up to Labrador. Between two spawning trips the fish feed far out in the North Atlantic, near Greenland and the Faroe Islands.
How does a salmon find its own river again?
Researchers think the fish reads the earth's magnetic field like a rough map while it is far out at sea, and then switches to smell close to the coast. Each river carries its own mix of scents, and the salmon seems to remember the one it grew up in.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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